xref: /dports/audio/bristol/bristol-0.60.10/ChangeLog

    0.60.10 27 Apr 2012 Maintenance release

Voices are given a small random detune. Pitchbend would lose this delta which
put the voices back in tune as soon as the pitchwheel moved. That altered the
width of the sound so added in the code necessary to maintain the delta values.
audiothread.c

Added in 'hi-res' skins for some of the emulators. This changes the rendering
to include a vector graphic stage where text and some line are rendered. It
makes the images far more scalable, ie, you can fullscreen them now without
getting pixel smashing.

Retuned the Mini filters. Fixed fastest attack rate to 0.5ms, the envelopes
were getting very 'ticky'. Increased the default Mini release stage to similar
values as note off were ticky unless Release was selected.

Jack MIDI configurations would only respond correctly on channel #1. Any other
channel would have the synth respond to the Jack MIDI messages but lose tracking
from the GUI, lose CC into the GUI as the channel identifiers could be lost in
the internal messaging.

    0.60.9 25 Oct 2011 Maintenance release, fanning linear potentiometers

Reworked the envelope to default linear attack and with gentler control of the
decay/release times. The linear attack was a Moog thing but was not universally
appreciated - it does not work very well for long attack times. Several synth
manufacturers preferred the use of exponential for this and other reasons.
The actual envelope code does not have linear or exponential attack as a fixed
value, it can be configured by the emulator although at the moment they all just
take the default setting, now linear. There is a ./configure option to have them
default to exponential rather than linear: --enable-exp-attack

It is now also possible to build with an alternative ADSR max ramp duration,
the following will give you a maximum ramp of 30 seconds, default is 10.
./configure BRISTOL_RAMP_RATE=30
These changes were to correct an anomaly in the previous design where the
actual ramp was a function of the sampling rate, hence if you step up to 96KHz
or even 192KHz for the improved sound quality then the ramp times would change
(now fixed). If you want to use very long attack times then exponential attack
will give arguably better results, that is admittedly opinion.

NOTE that these envelope changes will affect existing patches to some extent.

Added code to have fanning linear pots. The further the mouse is from the axis
of the pot the finer the value changes become.

Resolved a error in midinote.c that broke the scala file support. A patch was
posted to SFDN a long while ago now, this just rolls it into a release.

MIDI Program Change events were not being filtered by channel - they were being
tracked as OMNI. Applied same change to Bank Select. Have not tested all the
multilayered synths, they have exceptions since some use separate memory
indeces and some use combined settings.

Reconfiguring the continuous controllers as things like inverse mappings were
failing. The issue was that both the engine and GUI might be using the same
mapping file, dual inversion negated the effect. Corrected this with only doing
the mapping in the GUI but added a token called modWheel for the 'mcm' file to
allow the engine to have alternative curves for the modulation wheel.

The request to have an inverted modWheel requires the following: Start the
engine with -tracking to prevent the GUI tracking some events. Edit mini.mcm
and add in

modWheel: 127 0.001
modWheel: 0 127.0

This file is emulator global, ie, to have different settings with the same
synth then a user would have to configure different bristol cache variables.
A better way to do this might be to have an ALSA event manager in front of the
bristol emulators.

Ported over some note loss fixes from the 0.70 (smartphone) stream where with
excessive system load there were lost notes. This was never actually reproduced
on Linux so will discuss the fix with end users. The original change resolved
the issue when seen on a 600MHz ARM A8 on Maemo/N900 from Nokia and which were
also tested/confirmed on Android. It concerned signalling between the note
allocation code and the ADSR envelope states.

The multilayered synths would lose tracking of the PitchWheel - the pitch was
correctly calculated but only applied to the first bristolAudio structure in
the chain.

The Polysix gives click/tick at high frequencies and mods. The cause was the
change from the precached buffers to recalculated buffers. The code was changed
to have the buffers always calculated/cached on note events as a fix to the
existing band limited oscillator code. The code change was only the prophetdco
but it could be pushed into the other oscillators.

The BME noise mix was all but silent, readjusted the gain settings for the mix.

The Pro1 and Prophet10 saved sequencer memory was not reloaded on restart. Had
to apply changes to a few different parts of the arpeggiator/sequencer code.

Gain levels seemed low on the ARP 2600 and the Direct Out final stage gain left
a signal that was almost inaudible.

Added the option to use a memory barrier over the jack ringbuffer. The issue
is that the JRB can be demonstrated to fail on ARM CPU due to them having weak
memory ordering. Intel should not be affected. AMD is a marginal case. The
config option is --enable-memory-barrier which defaults to no barrier since
most of the installs will probably be on Intel.

    0.60.8 23 Dec 2010 Maintenance release, Hammond optimisations.

Made some changes to the way bristolrc is handled. If the file exists then a
seach is made for two tokens, PREARGS and POSTARGS. If they don't exist then
the same default behaviour takes place: all the contents are concatenated into
a set of options that are inserted before all the user parameters. If either
of these tokens are found then PREARGS are inserted before the user parameters
and POSTARGS are appended to the whole net commandline to the GUI and engine.
This gives a lot more flexibility to override default behaviour, for example:

PREARGS=-count 1024 -rate 48000
POSTARGS=-jackstats -jack -multi 0

Using such contents then the command 'startBristol -mini' would be expanded to

startBristol -count 1024 -rate 48000 -mini -jackstats -jack -multi 0

A part of the reason for the above change was that there were reports of issues
with the ARP 2600 and period sizes less than 1024. The culprit appeared to be
the -multi option, this defaulted to 4 for the 2600. Changed it to default to
zero with a need to then explicitly reconfigure it. The reconfigure can now be
automated in POSTARGS. The diverse Bristol front end appliations such as
monoBristol provide user arguments to the startup script, the current bristolrc
definitions can provide capabilities to extend how they operate as there are now
pre and post arguments that encapsulate the frontend parameters.

This release is noted as including hammond optimisations, these are not with
respect to CPU load, rather with respect to accuracy of the emulation:

Adjusted the B3 Preacher Compression code to provide a more pronounced non-
linear amplification. The results are interesting/different. It mixes well
with the new gearbox generated for a clean tonewheel (mostly sinewaves with
no crosstalk) and a mild crosstalk gearbox with some sliced tonewheel harmonics.
The control is not continuous, there are 3 stages which are selected as the
rotary changes position, this would normally be represented with radiobuttons
however the GUI previously only had a rotary control so this was used to prevent
a big reordering of the options panel layout.

The new tonewheel gearbox are in the factory shadow profiles, per default as
below. To test them then copy the target gearbox to your private memories
(these are the defaults, your installation may be different):

	source: /usr/local/share/bristol/memory/profiles/tonewheel*
	dest: ~/.bristol/memory/profiles/tonewheel

Also made few alterations to the B3 VC algorithm changing the tap gains and
LC filter values, altered the tap selections for the different 1/2/3 settings
and adjusted the selector mode to reconfigure LC and phase (which work in
combination) rather than the actual tapping points. More work could be done
but these do now give some different characteristics where previously VC3 was
the only useful setting. [Note: it would actually be quite easy to make even
further improvements here by using an alternative filter algorithm into the
different taps. The current one is a rooney which has weak phase modification,
it is similar to the original in as much as that could only introduce about
1ms of phase change however bristol has other algorithms that would give better
phase changes by frequency which would be closer to the Hammond vibra. The
current code overcomes the rooney limitation by taking the phase changed filter
signal (which has a phase change that is dependent on frequency) with an
additional phase change that is time constant. The issue is efficiency, the
rooneys are single pole and come almost for free. ffs]

Reintroduced some B3 code to give contact delays for each drawbar. The delay
is configured in the tonewheel file and is then a function of velocity. The
tonewheel file defines the maximum sample delay before any given harmonic is
activated and this delay is reduced depending on velocity. It is also possible
to configure a click sample per bus out of 4 available however the author
will state that none of the samples is accurate: click, thump, shelf, etc, is
not an accurate emulation. Depending on which source is considered authoritative
then the Hammond click may be a pure function of tonewheel position and its
activation point. This code emulates that effect with the option of adding in
extra effect as a combination of the tonewheel file samples and the overall
click setting. Note that the 'click' level does not affect the cut in points
of the harmonics, reducing the 'click' level will not affect the tick sound
when a drawbar contact is finally made. The harmonics do not have a constant
phase as per the original however the tonewheel file can override that to
emulate the L and M series spinets. With the current code, pressing a key very
slowly should result in the delays between the different busses being almost
audible, an effect that reduces with velocity. The configured Click is reduced
when the vibrachorus is on as is also heard on the originals.

This click code has actually been available for a few years, it was removed as
it affected other developments for gearbox optimisation. This optimisation was
to 'post generate' the tonewheels: if a harmonic was not needed then it would
never be generated. This was not condusive to busbar delays so now the decision
has been taken to drop the CPU optimisation in preference of a more accurate
rendition. At the same time the tonewheel damping was corrected so that, under
control of the Damp option, the summed levels of any given wheel is not linear
but is a function of the number of times it is tapped. It is noted here that
if no click is desired, at all, then the 'preacher' algorithm should be
disabled at which point notes are generated from zero point as per many of
the commercial emulators. Several of the later Hammond models reduced/eliminated
key click using various techniques, disabling the Preacher would give results
closer to the B2XX series organs. Disabling the preacher removes the damping,
busbar offsets, and all the other features of the tonewheel file.

Adjusted the click code to introduce changes to the bus offset delays by key
as well as velocity. The existing code used a single profile per gearbox but no
two keys would have had the same contact profile as this was based on aging of
the springs: the code now has semi-random delay selection. The 'semi' refers to
code that will select the same offsets if the same key is sounded sequentially,
this is how Jimmy Smith used to play key click with the same key - now the
delays for that sequential key do not change (they will if intermediate notes
are sounded which he also did and potentially the delay offsets may be prebuilt
for the whole keyboard rather than calculated, ffs). The different bus delays
only affect timing not the actual effect so if 'Click' is non-zero then the
sample selection per bus will be constant even though the delay changes. Now,
another affect of the bus delays is that if playing quickly it is possible that
a note will start and stop before even all the harmonics have sounded, this is
another trick of Smith when he played notes to not traverse the complete travel
of the key: not all harmonics would actually make contact and this is also
possible with bristol (depending on velocity, buffer size and configured bus
delays).

Added a -keytoggle flag, it affects GUI behaviour where a key is released when
the mouse button is released. Previously the key state latched which was useful
for polyphonic emulators but not necessarily for the monophonic ones. The
default operation is now not to latch the keys, this option overrides the new
default behaviour to give latching keys again.

There were some sticky keys and note 'ticks' when using the monophonic synths
with -nnp (no note preference). The polyphonic note logic could completely kill
notes when overvoice and if a keyoff event occurs for a voice on the new list
then some of the flags would get damaged. None of this happens with monophonic
note preference or with polyphonic synths (well, the ticks may still happen if
the polyphony is exceeded but get burried in the mix of multiple voices, ffs).

Bug report on some emulators defaulting to only one semitone of pitchwheel
depth. This turns out to be emulator aliases: the interface recognises some
alias names but it could not set defaults except on exact names. Incorporated
some changes to accept the known emulator aliases too.

Feature request that the SID should acknowledge pitchbend wheel as well as or
instead of pitchbend on the modwheel. Not a big change and the issue with the
MOD wheel is that it was difficult to tune having no notch. Currently both
controls can affect pitch but the modwheel can be turned on/off selectively.

There was a window when the global configuration options would not be sent to
the engine, a race condition. The result would be no output signal.

There was another race condition in the GUI library which for now has been
patched. The actual fix is a little larger but it will be left for future
research.

Found a bug in the MIDI handling code for NOTE_ON velocity zero being mapped
to NOTE_OFF velocity 64. When the ringbuffer was introduced the check moved to
the wrong side of the ringbuffer causing an endless loop at 100% CPU, for
some emulators quite a lot of nasty random noise and potential system 'hang'
for certain CPU configurations with RT scheduling. This had not been reported
which means either people did not bother or the use of NOTE_ON velocity zero
is not widely used.

Release 0.60.7 had an undocumented feature, undocumented because it was not
that big but it did go into the manual page. The option -jackstats will prevent
bristol from attempting to find out the current jack server settings, these
parameters would instead be defined with -count and -rate. This change fixes
some issues with jack connections, with LADI, and makes the GUI start a bit
faster as it does not have to poll the server from the script then reconnect
to the server from the audio thread.

The BME-700 Glide on/off switch was not active.

Roadrunner Vibrato was too deep, by a long way. Scaled back the tremelo at the
same time. Gentle vibrato was still possible but not under mouse control, it
had to be done with keyboard accel/deccel.

    0.60.7 22 Oct 2010 Maintenance release, minor features

Added in an option called -memdump which will copy all memories for a given
synth (specified with -emulate) to a target location. That location is then used
as the session cache so further changes will be made to the dumped memories.
That is intentional: this can be used with Session Management using a target
location in the session directory so that the session will include all of the
synth memories. The copy operation of the user memories only happens once when
the directory is created.

Added in an option call -neutral, this will initialise the emulator with the
value zero for all parameters. This provides a clean sheet from which to start
sound generation. The code is generic and there are some exceptions to where
it is applied: the organs and pianos do not implement the option, some of the
synths are exceptions too (P800, BitOne, DX) as they have a non-intuitive
interface that does not lend itself to being zeroed. For testing the few that
do not implement the option then '-load -1' can be used as a potential
alternative.

Added a runcom file "bristolrc" located in ${BRISTOL_CACHE}/bristolrc which
may contain the parameters that are always provided on the command line. The
parameters will be placed before the command line arguments so that they can
be overridded but they provide the possibility to simplify the command line
that needs to be specified when bristol is invoked. The variable BRISTOL_RC
can override the default location and the -rc option will circumvent it.

The size of the voice table is now a configure time parameter. There were some
requests for optimisation and reducing the size of these tables is a small one.
./configure BRISTOL_VOICECOUNT=32 is the default. This is not the max table
size which continues to be 128 voices: the -voices option is a runtime parameter
that can be used to increase the size of the table above the VOICECOUNT limit,
this ./configure option is just the default.

Resolved an issue with the filter tuning of a few of the emulators, they were
using an incorrect keyboard tracking value which meant that with the filter at
high emphasis there was discordance in the oscillator vs filter waveform
frequencies.

Reworked the summary text for small changes to some of the synth names: they
are sometimes different from the switches used to start them however the actual
name is required to be able to use emulate correctly. The -summary list will
list the emulators that have been finished, --summary will list all of them
even though a selection do not actually operate yet.

Removed the empty pop-up menus. The code is still there however it is no longer
called by either GUI or library. There were diverse requests to stop posting
them as they had no purpose.

Added an initialisation watchdog timer. If the audio thread does not activate
in this period then the engine will gracefully exit rather than just hang
around waiting for somebody to talk to him. The default timer is 30 seconds
but can be changed with the '-watchdog <s>' parameter.

The ARP Axxe was about a semitone out of tune. The cause was the logic behind
the pitch buttons which was broken.

Glide parameter settings could be lost on restart, the 'glidemax' parameter was
not being correctly initialised so remained as zero.

Remedied a test failure for the jackd binary. If jack is requested as the audio
interface then we need to connect to it to find the correct sampling rates and
period sizes. The check for failure of this request was broken.

Fixed a very arbitrary race condition between the audio and midi threads
causing segfaults which only happens during initialisation with heavily loaded
CPU. Doubt if this will have been seen outside of development as the window
was extremely small.

There was a spurious 'newline' debug message when active sense was detected from
a keyboard. Bristol does not support active sensing (except from the GUI) and
whilst these messages did not cause any issue with the synth operation they
were a great annoyance for the command line interface users. The print statement
was put under a debug flag.

    0.60.6 11 Aug 2010 Geometry configuration options, maintenance release

Was requested to implement a -geom option which would minimally allow for window
placement onto the screen. This seemed very reasonable so incorporated it. The
option will also take width and height parameters such as 500x200+100+100 and
where necessary break aspect ratio and configure antialiasing. If only one of
width/height is given then aspect ratio is maintained, and options such as
+100+100 will just affect window positioning. Options like -geom 640 will just
set the pixel width, maintain aspect ratio and take default placement, possibly
invoking antialiasing as well.

Randomised the TCP port numbers used to link the GUI to the bristol engine.
There remained an issue with the Jack Session Manager and configurations that
used multiple invocations of bristol: the TCP port identifiers would conflict
causing one of them to fail on reload. I think the option '-host unix:1234' is
a work around the issue as long as '1234' was always unique per bristol but
this only works on localhost as it uses unix domain sockets rather than TCP
domain. The longer term solution was to randomise the port numbers in the range
1024 to 16383, the transient service ports since otherwise there is still a
window for error if the TCP ports are not closed down cleanly (although that
is now finally a rare occurence). The port identifier can still be overridden
and will be inherrited by the JSM interface.

Resolved a few issues with different device drivers. OSS was actually broken for
a while due to incorrect flags and buffers and there were a few ALSA anomalies
although they were inadvertently correct.

Was requested to add a manual page for bristoljackstats for part of the debian
hurdles. Took the chance to also remove two ancillary binaries which generated
notes but were only for QA testing, not general distribution.

Added an option called -sleep which stalls the init process for <n> seconds.
This was too easy not to implement and may help to overcome what looks like a
race conditition when using a session manager to restart multiple Bristol
clients.

Corrected some ./configure options so that they correctly check for jack and
alsa header files rather than just the packages and libraries before including
them in the build. This change included adjusting the default drivers so that
OSS is configured when jack and alsa are not available.

    0.60.5 08 Jun 2010 Maintenance release

Fixed an issue with the SID where double clicking on the memory Load button
would turn on the soft chip debug code. This was a development feature that was
not intended to be distributed.

The -mono noise mod was originally just the literal noise source, this is not
a great mod and does not mimic the original which I think used a S&H circuit
on the noise source clocked by Osc3. Reworked this into the emulator anyway,
the sonic qualities are better. This should actually also be put into a few of
the other emulators (Prophets too for example).

The monophonic note logic no longer respected -nnp due to incorrect flag
management. This needed to be corrected as it was backing off to HNP which
implied that the engine ran constantly.

Discarded a check in the ShmImage code so that the check for support in the
server was dropped. Most servers which apparantly support the SHM structures
seemed to be responding negatively to the capabilities request which caused
backoff to the Pixmap interface. The current situation is that when compiled
with SHM support brighton will attempt to use it. If the server really has
issues with that then the -pixmap options will have to be requested manually.

Resolved a timing issue that can occur at startup, the event manager needed to
wait for positive status on the control interface before proceeding. Only
affected single core systems due to threading, and was naturally intermittent.

Failure to initialise the operating gain of the envelope when in some monophonic
note conditions could result in apparant loss of signal until the note states
were fully completed. This would manifest itself as either no output, low output
or even as lost notes over MIDI channels.

Midi debug flags were not being parsed correctly in the engine. Should not have
affected runtime as it was only a debug which is not usually active.

Changed the startBristol shell to request /bin/sh in place of /bin/bash.

    0.60.4 23 May 2010 Maintenance release

Coded an interface into the X11 SHM extensions under the configure switch
--enable-shmimage, some that was needed since the latest X11 servers have
dropped their support for XImage interfaces. This left only Pixmap which works
but is rather slow.

Added an option to restrict the rotary controller tracking to pure mouse up/down
rather than geometric positioning. This was on request and is -rud or -rotaryUD,
the value will be a fraction of the current window height. The code will respect
notched controls and similar stepped rotary types.

There was a bug in the event forwarding code that would damage intermittent
messages. The issue was masked for a few reasons: the key events did not use
this code path, controller events would be generated in such high volumes that
the loss was not visible. Program change was affected, also tacked on code to
address bank change events which were previously not distributed to the engine
although the way MIDI does bank management is not really consistent with bristol
memory management: bristol tends to work with banks of 8 or 10 memories as per
the old synths. MIDI runs with banks of 128 memories and the result will be some
overlap. It works as long as a single access method is used.

Added -stop as a method to reap any existing bristol processes. It will kill the
audio process if running which will result in any GUI dying due to the active
sensing. All processes will be terminated which may not be the target action if
multiple engine are being used, the options 'startBristol -kill -mini' will then
only terminate the engine and GUI associated with the mini emulator. This is
also not infallible as one engine could be running multiple emulators however
the goal was really just to terminate a daemonified engine rather than do any
really intelligent process management.

Added -cache as a runtime option to allow specification of the cache path for
memories and profiles.

    0.60.3 12 May 2010 Maintenance release

Reincorporated code for channel pressure recognition. It had been dropped from
an earlier release due to dumping core when applying the channel change to all
the voices associated with that channel. Also fixed up some issues with the
poly pressure handling, I think it was want to hit 100% CPU. This was also
ported back to 0.50.8.

Fixed a bug that had been reported a while ago against the MG1/Realistic of
corruption of the GUI image and loss of sound. The GUI corruption was due to
incorrect bounds checking on some bitmap manipulations which were corrected,
a fix that is applicable to all the emulators. There were a couple of other
specific issues with the MG1 and RhodesBass that had other consequences, also
fixed. This was ported back to 0.50.8.

Added in another velocity map: no velocity sensitivity. That should have been
there from the first implementation of maps but I think I got carried away with
the ability to add hundreds of different curves that this got swept aside. It
can now be requested with '-curve 0' to give something like a -3dB constant
velocity level for all struck keys. Ported back.

Put the autozoom feature under a configure time option --disable-autozoom, some
issues were reported where it would be apparantly get activated unexpectedly,
ie, the windows would constantly flip in size even though the -autozoom was not
given as a run time option. The ./configure option also removes the Enter/Leave
tracking which was the more probable cause of the error. There may still be
some issues with KDE4.4 that were reported. This code was tested against 4.3
and it does deliver a lot of seemingly superfluous ConfigureNotify which were
giving the window a Postage Stamp effect. Filtered out the ludicrously small
window sizes that were being proposed.

Added a preinstalled version check to the build scripts to exit configure early
if bristol is already on the system. The issue is that library directories may
be different between the two, most notably when the system package manager has
been used to installed as a part of the OS. It can be overridden with the flag
--disable-version-check although I did consider hiding this under an obfuscated
parameter name as the issue has come up several times now.

Fixed a core dump that could happen without the X11 libraries and a window
request that failed. This would always happen unless the -window option was
given.

The Explorer and Voyager mod bus ramp was actually coded as a square wave. It's
S&H was also very low. This also lead to more changes in the filter cutoff vs.
keyboard tracking, it is now a bit less bipolar.

This version includes a manual page, a common one for bristol, brighton and
startBristol.

    0.50.8 05 May 2010 Maintenance updates

Reincorporated code for channel pressure recognition. It had been dropped from
an earlier release due to dumping core when applying the channel change to all
the voices associated with that channel. Also fixed up some issues with the
poly pressure handling, I think it was want to hit 100% CPU. This was ported
back from 0.60.

Fixed a bug that had been reported a while ago against the MG1/Realistic of
corruption of the GUI image and loss of sound. The GUI corruption was due to
incorrect bounds checking on some bitmap manipulations which were corrected,
a fix that is applicable to all the emulators. There were a couple of other
specific issues with the MG1 and RhodesBass that had other consequences, also
fixed. This was ported back from 0.60.

Added in another velocity map: no velocity sensitivity. That should have been
there from the first implementation of maps but I think I got carried away with
the ability to add hundreds of different curves that this got swept aside. It
can now be requested with '-curve 0' to give something like a -3dB constant
velocity level for all struck keys. Also back ported.

    0.60.2 28 Apr 2010 Command Line Interface Changes, maintenance release

Added a play mode to the CLI. It can be activated with ':set play' and provides
an alternative key path directly to the frontend to send midi note events. The
code is only monophonic due to the way the raw interface works - there are no
qwerty key 'off' events so they have to be interpreted. It does allow for quick
testing of patches without having to resort to having a keyboard attached to
the engine. Exit from 'play' mode is as with the others, either escape or ':'
which at the moment cannot be remapped, something that might be an issue for
internationalisation.

Andrew requested monophonic sustain pedal support. This does not really fit
into a monophonic instrument: if all notes sustain then with note precedence
the only note heard will be at the outer one. Using sustain with a polyphonic
assignment algorithm over one voice works. For the HNP and LNP another
algorithm was added that holds the other extreme note - the lowest with HNP or
the highest with LNP - this is the note that will fall back when no other keys
are held during sustaining notes. When a more extreme note is played it then
becomes the 'extreme' note.

Julien reported some lost note events which was a bit disconcerting. Reproduced
an issue where the events were not lost but their triggers could be: if a noteOn
event arrived it would set the trigger flags. If a noteOff occured in the
same sample period it would clear these flags which is incorrect for the
monophonic note logic. (to be confirmed). This required a couple more patches
for glide errata reported separately and largely related to inversion of the
glide rate when the pitch wheel was moved causing Inf to be generated.

Colin Fletcher requested that something be done about the device names in jack
and eventually ALSA midi. The fix is not straightforward as the engine does not
know a priori what it has to emulate when it opens the MIDI interface. The
current feature is that the engine recognise the -emulate <synth> and use the
synth name here for all registrations. Added to this another alias called
-register <name> which will set both audio and MIDI devices names to the given
name and can be used to override other settings.

Extended the CLI midi command set to include 'set midi controller <id> <value>'
to give access to the MIDI controller interface. May be of limited operational
use but as a debuging tool it is very helpful - with alias supported it can be
used to generate NRP, RP and the rest. This was implemented to debug Andrews
issues with CC #64 (sustain) and used it to also debug Juliens issue by the
same manipulation of the sustain flags.

Cleaned up the build processes so that they really do not need X11-dev to be
installed. The previous releases did require the X11 headers due to some stray
ifdef in the brighton header files, even if --disable-x11 was requested. Now,
for the correct build process it is necessary to define --disable-ximage too
although the ximage is really informational only, ie, it would not be compiled
anyway without X11 being enabled. It was left in as it gives an error message
regarding the missing X11-dev headers. May remove that in the future.

Cleaned the code up to remove the size warnings. They were almost uniquely on
printf statements. The only remaining warnings should be for some unused
variables which can be cleaned up later, and my explicit warnings for some
potential issues that may need to be taken care of (again, at a later date).

    0.60.1 23 Apr 2010 Command Line Interface Changes

This release is primarily a cleanup to the CLI, first released in 0.60.0.
There were a few bugs that became evident, some incorrect cursor positioning
and hence occasional garbled output. A couple of CLI features were also added
which include extensions to the completion and the ability to add commands to
the accelarated keycodes in ESC mode.

Finalised the CLI command completion code such that it can pretty much complete
the whole tree with reasonable help information available.

Changed the CLI alias variable replacement such that variable $i is the param
of that index from the alias command line, the previous syntax was a little bit
unusual where a $ would just take the current variable index and % would make
the variable increment.

set alias trans Osc1 Transpose=$2; Osc2 Transpose=$1
set alias
       trans: Osc1 Transpose=$2; Osc2 Transpose=$1
transpose 1.0 0.2

This will set Osc to 1-Octave transpose and Osc2 to 5-Octaves

Added the capability to set CLI key codes in ESC mode to call any :insert mode
command. The interesting feature is to be able to configure aliases in the
CLI and then give then single key accelerator codes:

1. set cli q quit
2. set alias panic set midi panic
2. set cli p panic
3. set alias clidata set cli
3. set cli ? clidata

The first will allow the use of 'q' to exit the emulator, trivial example but
the point is that the CLI :insert mode command 'quit' is now available in ESC
mode. The second one is potentially more useful, it links the ESC mode char p
into a MIDI panic event which causes alls- notes-off. The third one adds a help
function to escape mode: if you now type '?' it will list the CLI accelerator
keys and their functions.

This cli/alias feature can also be used to provide seach accelerators for
selected synth parameters:

set alias vol Volume
set cli v vol

Now when in ESC mode the single key 'v' will take the Cursor to the Volume
control rather than having to /search for it or use the Cursor left/right
motion. Several of these can be constructed to allow fast navigation through
the parameters, one to jump to filter parameters, another to envelope, etc.

Added some options for changing parameters from the :insert mode in addition to
the <Variable>=<value> that was implemented in 0.60.0. The new modes are '+' to
increment by 1%, ++ to increment by the 'set accel' value, and +=<value> to
increment in given steps. Decrement have similar actions too:

mini mem 0 chan 1 # Tune=0.5
00 Tune                     :  500
mini mem 0 chan 1 # Tune+
00 Tune                     :  510
mini mem 0 chan 1 # Tune++
00 Tune                     :  610
mini mem 0 chan 1 # Tune+=0.09
00 Tune                     :  700
mini mem 0 chan 1 # Tune-
00 Tune                     :  690
mini mem 0 chan 1 # Tune--
00 Tune                     :  590
mini mem 0 chan 1 # Tune-=0.09
00 Tune                     :  500

Some of the same syntax was added into the 'set brighton device <p> <o> <val>'
such that where previously value was an exact value it can now take +=<f> and
-=<f> to give relative changes to variables. This has some value for a few of
the synths (poly800, bit series) where different panels may be required for
data entry and parameter selection. The Poly800 has now been populated with
text names for its panel parameters however to make it useful please contact
the author to get hold of a suitable set of aliases for changing the data entry
controls.


The ARP Odyssey emulator now has a 'Dual' option on one of the VCO. This will
make one VCO assign itself HNP and the other LNP to get two note logic. This
is not really dual voice as there is still only one set of filters and amps. It
is not a feature of the original, it kind of emulates another emulator. To
prevent unexpected results the code is not applied when in polyphonic operation
as it relies on the monophonic note logic to decide which are the highest and
lowest notes being held down. The feature is gimpy but more fun could probably
be had by starting two independent Odyssey on the same engine and midi channel
then applying HNP to one, LNP to the other.

Several changes were again added to the log file processes to remove a race
condition on file open status. This only showed up on multicore configurations.

Patched up some compilation directive errors for FreeBSD distributions, also
removing a stray ALSA header that should have been placed under a compilation
ifdef for removing its support. This was primarily for debian support.

    0.60.0 19 Apr 2010 Command Line Interface

Bristol now has a command line interface available from '-cli'. If the code is
built with --disable-x11 then it can be compiled without any X11 dependencies.
When built with X11 then specifying '-cli' will open both the CLI and the GUI.

The CLI is based on a VI type interface and will respond to the arrow cursor
keys: each parameter is available with Left/Right, and it's value can be changed
with Up/Down for accelerated control.

When started it is in escape mode and will also respond to the following keys:

CLI: h left
CLI: l right
CLI: ^k incmin
CLI: k inc
CLI: K incmax
CLI: ^j decmin
CLI: j dec
CLI: J decmax
CLI: M memUp
CLI: m memDown
CLI: r read
CLI: w write
CLI: x toggle
CLI: / search
CLI: u up
CLI: d down
CLI: U fineup
CLI: D finedown
CLI: : insert

These mappings are saved in the synth profile and can be edited to change the
them: '~/.bristol/memory/profiles/<synth>'. These mappings are additional which
means the above values represent the default mappings that always exist. There
is a keyword 'none' which will disable any key operations that you do not want.
They call also be configured from the command line with 'set cli <k> <action>'.

Typing ':' goes the the VI style command line in insert mode and will accept
the following commands:

GUI commands:

        find: [free|load] synth memory search
        read: load synth memory at the configured index
       write: save current synth settings to memory
      import: [path [mem]] read a file and save to memory
      export: [path [mem]] save synth memory to external file
        help: this screen
         set: [line|debug]
        midi: command set to engine (X)
       debug: [on|off] CLI and engine debug settings (CLI only)
     bristol: [cont/op/value|register] - operator commands
    brighton: [panel|p/d/v] - GUI management commands
         cli: [list|<key> action] navigation key management
       alias: command aliases, %/$ signs will be remapped parameters
        quit: exit application, terminate the emulator

The command line has a history buffer of the most recent 50 commands and any
consequtive duplicates are supressed. When in ':insert' mode then the cursor
motion keys will nagivate this history and give command line editing. The keys
'^p' and '^n' are also history forward and history backwards respectively.
There is a variable called 'set history <n>' which will limit the number of
history lines that are ever displayed, either with the 'history' or the
'set history' command, this is for small displays. The command line can be
edited with ^W (kill-word), ^U (Kill-Line), ^A (start-of-line) and ^E (end-of-
line).

The shell command line history can be re-executed with :!<n>, :<n><TAB>
will complete the line from the history buffer and leave it available for
editing.

When in ':insert' mode the <TAB> key will list available commands and complete
them where possible. Commands strings do not have to be complete to be executed,
they only need to be unique. If a command cannot be found from the above list
with the <TAB> key then the current line is used as a lookup into the synth
parameter list with the following syntax:

: LFO<TAB>
: Osc 3 LFO
: Osc 3 LFO=0.5

The tabbed search here is for the given string anywhere in the synth parameter
name, not at the start of the name. If the string is not unique then the matches
are listed.

When in Escape mode it is possible to search the emulator parameters with the
VI '/search' key and TAB is also available.

/lfo - find all parameters that contain the word lfo, complete if only one
/^lfo - find all parameters that start with lfo, complete if only one

To toggle from ':insert' mode to ESC mode either type ^C (Control-C) or <ESC>.

The CLI is available for the following emulators:

    Mini
    Explorer
    Voyager
    Odyssey
    Axxe
    B3
    BME700
    Realistic
    Juno
    Jupiter
    PolySix
    MonoPoly
    OB-X
    OB-Xa
    Pro1
    Prophet5
    Prophet52
    Prophet10
    Sonic-6
    Stratus
    Trilogy
    Sidney
    Solina
    Vox
    VoxM2
    RoadRunner
    Rhodes
    Rhodesbass

The arp2600, bm, bit1, bit99, bit100, dx and poly800 have not been converted
and are for future study. The bit and Poly need a separate interface due to
their input methods. The 2600 needs some method of representing the patch cable
configuration. Now the CLI can still be requested for all of the emulators but
only those listed above have (almost) descriptive text for each parameter.

There are a few CLI variables that can be set:

set history <n>
set savehistory on
set line <n> [CLI line width]
set accel <f> [Controller acceleration for Cursor motion]

The savehistory option will overwrite the emulator profile file with every
'quit' commands. The 'line' option defaults to 80 columns but is configurable
for small Braille displays.

The CLI supports alias definitions:

set alias trans Osc1-Transpose=%

The command 'trans 0.5' will cause a transpose request to be made to the
engine. Multiple commands can be aliased together using ';' between them.
Multiple parameters can be set such as

set alias trans Osc1-Transpose=%; osc2-transpose=%
trans 0.2 0.5

Here, the '%' is replaced with the alias options on the second line, each
% will move the argument list forward. The command will send two different
transpose events to the engine. Conversely:

set alias trans Osc1-Transpose=$; osc2-transpose=$
trans 0.2

Here the '$' does not move the variable forward so the same value is taken.
This will cause the same transpose value to different oscillators. Any defined
aliases will be added to the list of available commands and shown in the help
menu, as will the list of <ESC> mode keyboard shortcuts. Aliases can be deleted
with 'set noalias <name>'.

The CLI prompt can be configured. Typical values could be plain text for the
emulator type but there are also variables available:

set prompt mini
set prompt %algo%:
or more usefully
set prompt "mini %memory%: "
will give
mini 99:

The tokens 'channel', 'algo' and 'panelid' are also recognised.
It is also possible to give the name of any of the synth variables in the prompt
too in which case they are evaluated:

set prompt "%algo% mem %memory% chan %channel% # "
mini mem 23 channel 2 #

set prompt "%algo% layer %PanelSwitch%: "
obxa layer 0:



Fixed an aged issue with the Explorer/Voyager that they produce no sound by
default and even then they are very, very noisy. Not sure why it never got
reported. The noise was originally due to injection to make the filters self
oscillate but become noise after one of the many normalisation rounds.

After integration of the CV IO for the ARP it was time to change the diverse
Keyboard Tracking inputs for the oscillators and filter. Up to now they had been
inactive, the tracking was integral to the operators. Now they can be remapped
from any of the other outputs which gave some facilities to get modwheel to
frequency mapping and improve the filter keybaord tracking.

Change the MIDI device selection such that '-midi alsa' configures a SEQ
interface rather than ALSA raw. This has caused a few error reports from people
who have not got the expected result. Selecting a raw ALSA interface is now done
with '-midi rawalsa' or '-midi alsaraw'.

    0.50.7 22 Apr 2010 CV Keyboard Tracking Frequency Control for ARP

After integration of the CV IO for the ARP it was time to change the diverse
Keyboard Tracking inputs for the oscillators and filter. Up to now they had been
inactive, the tracking was integral to the operators. Now they can be remapped
from any of the other outputs which gave some facilities to get modwheel to
frequency mapping and improve the filter keybaord tracking.

Several changes were again added to the log file processes to remove a race
condition on file open status. This only showed up on multicore configurations.
This was a 0.60 backported fix.

Backported the 0.60 fix for an aged issue with the Explorer/Voyager that they
produce no sound by default and even then they are very, very noisy. Not sure
why it never got reported. The noise was originally due to injection to make
the filters self oscillate but become noise after one of the many normalisation
rounds.

Patched up some compilation directive errors for FreeBSD distributions, also
removing a stray ALSA header that should have been placed under a compilation
ifdef for removing its support.

Since the release of 0.60 this stream is now in maintenance only.

    0.50.6 08 Apr 2010 Multiple IO Channels for audio/CV, more NRP Controller Support, Jack Session Manager maintenance

Made the audio engine allow for registration of multiple ports into Jack. This
gives the stereo in/out that always existed plus up to 16 additional ports which
will be used according to the emulator requirements. In the short term this will
only be the ARP 2600 which will register 4 extra IO for CV inputs. Future code
will probably be the mixer that has been kind of waiting around for a while now.
The option '-multi <n>' specifies the number of channels that will be opened to
the jack daemon. The input and output signal levels can have a correction
applied to them, -migc and -mogc each take a floating point which will adjust
the gain on the signal, applying it to all channels. The default gains are 1.0.

The signals for this IO are normalised to +/-1.0f although the ARP shouldn't
have issues with a wider signal range. The tests executed in house used two ARP
both connected up to Jack, one driving CV into the other such that the Envelope
from the first was applied to the filter of the second for example. The signal
levels were within the range 0..1.0f from the envelope however AC signal will
have a negative range too. That may be an issue for some other targets that do
not want their CV to go negative so outputs 3 and 4 have a DC normalised signal
with clipping below zero. Extensions to the CV configurations for the other
emulators is for future study. The issue is not how to get the signals into or
out of the emulators but a question of how the routing should be defined. For
the ARP 2600 the signals can be patched as required.

A part of the IO functionality testing was done with session built by the Jack
Session Manager so that two ARP 2600 could be loaded and signals passed between
them. This lead to a number of fixes to parts of the naming structures, not
really bugs, just things that would only really have come to light when running
multiple instances of bristol with jack and jsm. The fixes included removing
any auto-connection options if there were any jsm options present, renaming the
windows so that the title includes the device name from the Jack interface to
help identify windows in duplicated setups, more small adjustments to the
parameters parsed to the JSM command line, some changes to the import and
export routines used to load the JSM saved memories.

Recoded the GUI NRP support so that it can track NRP parameters. It requires
the GUI be started with the -gnrp option. The code does not support ganging:
tying multiple GUI devices to the same NRP however that may change presently.
The existing CC control registration can be used for that purpose. The NRP
support is naturally affected by all the usual limitations of NRP: they are
assigned to MIDI channels not device targets (which SYSEX does do). This means
if two devices are on the same MIDI channel it is up to the user to ensure that
the NRP they use do not have conflicting actions. The NRP mappings are saved in
the same profile as the emulator CC, CM and keyboard mappings. Per default the
mapping table size has 128 entries which matches the CC counts and should be
enough for any of the current emulators. A parameter -nrpcc can be used to
change the table size.

The emulator settings will now be taken from the emulator header files rather
than pure runtime switches. This imposes the use of the '-emulate' option which
previously had this function. The choice was based on a discussion with Andrew
Coughlan: if we are emulating then consider defaulting the closest match to the
original, users can override options afterwards. This means a Hammond will start
with the maximum voice count available, for example, but a Mini Moog will start
with just one voice, highnote precedence. Changing the number of voices after
definition of the emulator can make the Mini run as a polyphonic instrument if
desired. The algorithm search is strict, ie, only the emulator names from
'startBristol -summary' are recognised. This is in contrast to the remaining
parameters that do take some aliases (-arp is the same as -arp2600 for example).

Needed to suppress a few more options from the command line presented by bristol
to the Jack session manager. These were port, rate and count which are all
dynamic parameters anyway. Not supressing them lead to their duplication and
some undesirable side effects of that.

Renormalised the trilogy output signal after some advice on their levels.
Changed the configure flags to include options for separate default audio and
MIDI drivers - Jack audio and ALSA MIDI was quite popular.

Fixes some repainting issues with the vertical sliding controls, they left a
trace of noise on the way down.

    0.50.5 03 Apr 2010 Jack Session Manager Immediate fixes

The code now can actually save and reload sessions on request of the jack
session manager API. 0.50.4 will be delisted.

Added a -import flag which will take a file and load it into the synth at init
time. This may fail if the memory was for another emulator however it can ease
file/memory interchange. The memory is not directly saved into the bristol cache
but still needs to be saved to some (free) memory location in the emulator. The
flag is actually an alias for -jsmfile which was required to do the same for
the jack session manager.

Added in runtime options to support keyboard splits. Not sure why this took so
long as it is a base requirement but as it is also possible from a master
controller it never made it yet. The two options are -highkey and -lowkey and
apply to single emulators. Error checking is minimal: values outside of the
7-bit MIDI note range are not checked, low > high is not checked, ie, it is
possible to build configurations that will not work. They will not break the
emulator but no response will be heard.

    0.50.4 02 Apr 2010 Jack Session Manager Support

Installed the svn jackd version with session management support to start work
on coding the interface. It required a few changes, not just to the way that
the jack interface had to work but also to the bristol message passing to allow
for arbitrary strings to be exchanged rather then just control and operator
data. Similar to the LADI code, the session requests come into the engine, it
then has to take care of redistribution to the GUI where save operations are
actually executed. The interface is perhaps not quite what JSM expects but that
is purely a bristol internal working issue: Jack session requests come into
the engine only, they are translated into bristol session requests and then
distributed as required - to the GUI. Bristol session management includes the
capabilities to both save and recall setup however the save and recall source
can only be the bristol cached content, not from an arbitrary file. to overcome
this, when a save request is sent from the engine to the GUI, it extracts the
file path. Memory is saved to a private entry in the cache and then this private
file is moved (exported) from the cache to the target location. The load request
works similarly although Load requests do not come from JSM which does not have
this feature. The engine command line parses the -jsmfile option and sends a
session message to the GUI to import and then open it. There is the -jsmuuid
option which is used by the session manager to direct the aplication to
register with the given ID. There is one additional option which is -session
which will disable all session management, including LADI.

Removed the incorrectly remaining 1/2 sample phase correction from the reworked
Huovilainen filters for the non-resampling algorithms. These are called when
the samplerate exceeds 80KHz as the point where the filter quality starts to
degrade is far above the audible operating range of the filter. These have not
been widely tested and an override could make sense.

The OB-X filter code needed some corrections for the performance changes, the
code was there by the command line options were different matches. Also added
some more frequency corrections for keyboard tracking of the filter.

Resolved an error in the jack ringbuffer management. The buffer would fill up
and give 'ringbuffer exhausted' messages under specific circumstances: running
as a headless server with last GUI detached whilst still receiving MIDI events.
The fix was belts and braces, the buffer is reset in the audio thread if it is
idling without emulators and the ringbuffer is also stopped with the last of
the emulator to exit, restarted when new ones are created.

The GUI still had some legacy support for controller registration against things
like RP, NRP, DE. This is supposed to be disabled if -nrp is given however the
flag was not being honoured. This is a kind of workaround, a bigger fix would
be to correctly register them however that leads to some issues with table sizes
that will be left for future study. This whole area is a grizzly part of MIDI
and should really be resolved with an alternative protocol.

The default build is now without the semaphores, they can be re-enabled on
request at configure time. Also added a config option for the default drivers,
the can default to alsa or take an option to use Jack as the default.

The mini emulator GUI would show key motion for midi channel and channel+1, this
was caused by an incorrect key panel flag. The engine did not respond on both
channels, just the frontend.

The Rhodes emulators stopped working due to some code that looks for the skins
not functioning on their internal contructions.

    0.50.3 17 Mar 2010 Band limited oscillator corrections, filter optimisation, GUI enhancements.

Corrected (most) of the previous restrictions on band limited oscillators,
namely that they were precomputed tables rather than dynamically limited. They
did give different signals than the mathematically built infinite bandwidth
waves (-blo 0) however they did not really prevent aliasing at the highest
frequencies. The code now does cut in bandwidth limits depending on a few run
time parameters:

    -blo n         - maximum number of harmonics to map, defaults to 31
    -blofraction f - upper frequency limit as fraction of samplerate (0.8)

The code will attempt to stuff as many harmonics up to 'n' such that the
fractional limit is not broken. Using values > 1.0 will lead to pretty wild
aliasing, lower values will thin out the sound but exhibit fewer artifacts at
the higher frequencies. The default value is admittedly above nyquist, this is
a tradeoff between distortions and waveform content. The code uses precomputed
tables for all frequencies where freq*n does not exceeded f.

Reworked the Huovilainen filters to move the expensive maths into the feedback
loop only. This reduces filter CPU requirements by about 90%, naturally at the
cost of some quality. The net results of the changes do not degrade quality that
excessively and due to the amount of reports of CPU exhaustion there are new
filter options: -lwf are the chamberlains, -hwf are the original heavyweight
Huovilainen and the default are the optimised ones. These are all run time
parameters per emulator. There is still the overriding -glwf option to enforce
all the emulators to use the lwf option globally. There is further filter option
which is -wwf, these use about half the CPU of the -hwf filters, they use the
same overall architecture however use a different but also more efficient non-
linearity giving a 50% lower CPU footprint. The default filters may also be
requested with the option -nwf, normalweight fiters.

Added some new corrections for the filter frequency tracking and especially
keyboard tracking changed considerably. It can now be played in tune when at
full resonance and can self oscillate at some settings.

The window now has a zoom accelerator under '<Shift> Enter'. This will toggle
between native window size and full screen. The native size the the one at
which it was created including applying any scaling parameters. The code will
introduce some image antialiasing when it scales to full screen, this remains
after returning to native size.

Used the same code to have window scaling accelerators: '<Shift> +' will make
the window about 10% bigger, '<Shift> -' will make it similarly smaller.

With the zoom accelerators coded it was then possible to add in the -autozoom
feature such that when the mouse enters the synth window it is maximized and
when the mouse leaves it is minimised. Both windows remain active however they
can reduce screen clutter. Width and scale will define the minimum and maximum
window sizes.

Added an option -width to speficy the minimum starting window size. This works
in conjuction with -autozoom and -scale so that between them they set the min
and max resize limits. There is no corresponding 'height' option, the height
of the window will follow the aspect ratio for the emulator. The option only
works with autozoom, if that feature is not required then the -scale option
should be used to set the actual window size.

Fixed the responses to FocusIn and FocusOut, they were silently dropped in the
earlier code releases but were now needed for the autozoom capability. With
these in place the opaque resize aspect ratio management was changed such that
the resize results in the window getting morphed to fit the window and then
aspect ratio being enforced after the resize has finished.

Glide and pitch bend did not work together: glide was cut as soon as pitch was
altered. The fix was a one line change to the frequency assignments, previously
target and current were set by the pitchwheel, the change was only to adjust the
current.

There was an issue with logging to the user home directory, in most cases the
log file would be opened truncated and never used as destination for output
messages.

    0.50.2 06 Feb 2010 Real time processing enhancements

Added code for Jack Sample Accurate replay. This was a compromise for a useful
if awkward feature to implement in bristol: it is only implemented in the
bristol envelope code such that note_on events will be sample synchronised
to the offsets reported by Jack MIDI events. All other events will be period
synchronised as the Jack MIDI events are handled in the audio stream so are at
least guaranteed to occur within the given period even running at double speed,
etc. There is no intention to synchronise all the audio generation code and as
this is working as an emulator that is not considered relevant - the original
instruments all had free running oscillators and as such were did not have any
kind of synchronisation to note changes. We are not going to attempt to have the
exact same sound come out at the exact same point however the major state
transition at note on will happen at the desired timepoint. Some of the
emulators already had trigger synchronised LFO, these are now also sync to note
offsets from Jack although the net effect will probably not be much due to these
being low frequency hence low rate of change over the Jack frame offset reported
in the note event.

Placed the use of sem_init under a complation flag, preferring sem_open instead,
improves portability except that sem_open requires root privileges and PAM does
not seem to support any security permissions for this. To use the sem_open call
then './configure --enable-sem-open'.

This last change was probably superfluous as code was also added to remove the
necessity for the semaphores in the first place. They cause issues with the RT
threads and so incorporated a ringbuffer for note events from the MIDI thread
to the audio thread. This adds a little extra processing but not excessive.
This is a compilation time option, './configure --disable-semaphore', it will
eventually become the default sequence or potentially put under run time
options. The code was not completely trivial as the system needed to be able to
distinguish between where events came from, and if jack then checks were needed
to see if it was from a single registration or multiple registrations - the
former actually ends up with two threads that can recieve messages, the MIDI
thread fielding events from the GUI (including note events) and the audio
thread itself - the sample ringbuffer code only supports singular TX/RX of the
ring. Added some flags to the messages buffers to indicate source and make
the choice of direct handling from audio thread messages or indirect handling
via the ringbuffer under other circumstances.

Coded a second ringbuffer for event forwarding. To ensure low latency then it
was not advisable that the RT threads did event forwarding to TCP however this
is needed to get event tracking from engine to GUI. The second ring buffer is
for the path from the audio and MIDI threads to the otherwise idle parent thread
who then does the forwarding from the ring buffer.

Fixed an issue where inability to find the bristol profile files would result
in total loss of output signal. The cause was failure to default the velocity
and frequency tables when the configuration files were not found.

Removed some compilation flags that were specific to my system ready for
distribution. Version 0.50.1 probably had compatibility issues due to these.

    0.50.1 22 Jan 2010 Usability enhancments, LADI level 1 compliance, process distribution

Implemented code for LADI level 1 compliance. This required a few changes, not
just to accept SIGUSR1 to save state but also to have this possible in the
engine and GUI. For the GUI this meant adding startBristol code to exec the
GUI (or engine for that matter) rather than fork it, then have it trap the
signal and save a state file. For this to work in the engine, seeing as it does
not maintain state, it requires the signal be trapped and later a message sent
to the GUI to save the state. This last one caused diverse issues that needed to
be resolved to clean up some SYSEX handling. The code will accept options to
field LADI only in the engine, only in the GUI, or the both. The default is to
field in the engine. There is an option for the state file memory index. At the
moment bristol does not keep an arbitrary state file: the call is a tack into
the existing memory save routines so that memory, chord and sequence information
is also saved, this code section only accepts an integer which is the memory
index. If both -ladi memory location and a -load options are given then the
LADI state memory will be loaded if it exists, otherwise the -load memory will
be activated and then becomes the template for the LADI state file.

Reworked part of the Jack audio library on request of Nedko for LADI support so
that the client interface is only opened once, in the audio thread. Without this
he was seeing both audio and MIDI threads opening an interface and this did not
map into his registration routines and PID mapping. Previous
releases incorporated separate Jack registration requests in the audio and
MIDI threads using different symbolic names. This worked however was a bit
cumbersome for LADI support. The MIDI code can now reuse the audio registration
from the audio thread, just adding an extra MIDI port to it. This became the
default Jack behaviour with a -jdo option to enable Jack Dual Open if still
needed later. The operation of the -jack flag also changed to configure Jack
drivers for both audio and MIDI. Prior to this the -jack flag only configured
the defaults for the audio interface and kept the ALSA (-midi seq) option for
the MIDI interface. The previous functionality can still be requested with
the flags '-jack -midi seq' or just '-audio jack'.

Integrated several keyboard accelerators, these were requested as a set of
usability enhancements. The include ^S, save, ^L, reload, ^X, exchange two
memories, ^K, print the list of shortcuts, ^H/^?, print help information which
is the text writeup for the emulator. The actual readme is now built from this
output. Parts of this code (specifically the save routines) were used for the
LADI state save routines.

Cleaned up some issues with the MIDI interface flags, the readonly input to
bristol needed to be configured as an output into ALSA, something that was
being mixed up. This may be ported back to 0.40. Affected midithread.c and
midiSeqDevMan.c only.

There was a bug in the memory file management code that cause a spurious
directory 'memory' to be created in the users home directory if the emulator
did not have a private memory path. It was also created in $HOME/.bristol as
well, correctly, however the code did not return on the first creation.

The BRISTOL_LOG_CONSOLE environment variable was changed to be a true/false
flag. The run time equivalent option -console should now be honoured under all
circumstances which was not the case previously.

Cleaned up the closedown procedures for the situation that jack decides the
process is 'zombified' (sic) when it is actually under CPU pressure. It used
to leave the engine hanging around. The issue was not always obvious due to
alternative TCP port selection but it was still wrong. The processes should
now exit more gracefully although jack could be a bit more flexible here as
the cause of the original hanging processes was libjack blocking disconnects
from a process it had flagged as 'zombified' (sic).

Added key handlers for left and right arrow to give more controller tracking.
The Up/Down keys already moved controllers, with shiftkey accelerators, the
Left/Right now give more movement than up/down.

Integrated another fix for loss of keyRepeat functionality on exit: there was
a window where repeat could be turned back off if the mouse re-entered the GUI
window before engine negotiation had completed.

The following changes would have been in 0.50.0 had it been released:

This is actually a new software stream, the changes required to give correct
distributed processing were sufficient to be kept separate from the 0.40
release even though there do not appear to be a great number of features.

This release 0.50, is going out first as unstable. Many fixes for bugs found
whilst working on this code were put back into the 0.40.7 release which is now
considered to be stable. Having said that, this release is the first to include
some form of quality assurance. The process of SQA rotates around the
distribution capabilities: a single engine is started in one window, and then
a scripted procedure runs sequentially through every emulator, starting and
stopping every 10 seconds (roughly). During the whole process note events are
being sent to the engine and redistributed to the GUI. The SQA test is only
considered to have passed if it runs without any form of misbehaviour. Typical
cycles are somewhere over 2000 iterations.
Failure includes any crash the GUI or engine, loss of audible signal, exhaustion
of any of the library resources (handles, devices, etc), memory leakage or any
recognisable memory corruption. This is neither the simplest nor the most
complex test procedure. The first iteration just restarted a single emulator
1000 times, after that it became starting all of them, and then adding note
generation. There are two other scenarios that will be in a final test sequence
(at a later date) which will include multiple synth pairing and also program
change events. The multiple synth pairings will be interesting, it should
involve generating notes to every possible pair of layered synths (about 1200
cycles) including stopping and starting all of them each time on the same
engine.

Added a -log option that causes output redirect to a file. Will first attempt
to log to /var/log/<process>.log if permitted, otherwise it will attempt
~/.bristol/log/<process>.log with file truncation if logging is to the home
directory. As a part of this operation the whole logging mode was altered such
that a separate thread now takes control of stdin/stdout and stderr, timestamps
the output messages before printing them. Finalised this with a -daemon option
that detaches the controlling terminal and implies -log and -server. It is noted
that -daemon holding open files in a users home directory is potentially not
optimal so this mode would best be used as root with open files in /var/log.
It is possible to override the use of the log thread by setting an environment
variable BRISTOL_LOG_CONSOLE, this prevents the thread creation and continues
to output to your TTY.

Had to rework the brighton thread management to allow for asynchronous MIDI
event distribution. It may need more testing so will go out as unstable - there
were quite large alterations required but it lead to better general thread
management in the GUI: it no longer exits forcefully on window requests or
interrypts, it flags the threads to exit gracefully. The changes all passed
through the SQA hurdles discussed above.

Finalised the event redistribution code so that only the GUI or the engine
need to be aconnected to a real midi interface (or sequencer interface). Events
arriving on this interface are redistributed to tcp ports, ensuring that the
GUI and engine always track the same events. There is an override of this
functionality using -forward (discussed below) and forwarding is on by default.

Added an option -sysid to specify the MIDI SYSEX system ID for communication.
This needs to be entered as a 32 bit hex value. It will override the default of
0x534C6162. This followed an interesting discussion on LAU regarding controller
identifiers. The theoretical collisions that could happen should not have
affected bristol since SYSEX is only used over the TCP connection from GUI to
engine however the feature was cool enough to get implemented. For those who
are interested, the default SYSID is 'SLab' in hex, the bristol MIDI interface
extended from the SLab design.

An issue was reported with -voices 1 not giving any sound. This turned out to
be true and the workaround (now the fix) is to use -hnp or -lnp with either the
-mono flags or when voices=1. The code also now configures the note precedence
automatically (although it can be overridden). [And the last note precedence
code should also now be fixed too. nc.]

Fixed a spurrious compilation issue when Jack drivers are not found. Code was
still attempting to make a library call that was not compiled into that library.

Reworked exit conditions so that the processes can return reasonable status
back to the caller. That was not the case with the GUI and even if it was then
the startBristol script needed to still consider these exit status.

Did a cleanup of the build process to remove some spurious warnings that should
not have cause any issues with the code but did make the pedantic compiler churn
out messages. The remaining output should primarily be for my own warning
statements and a few unused variables/routines in the unfinished emulators.

Added an option -window to prevent posting of the GUI window. This is for SQA
testing where each emulator is started in turn in a constant cycle of thousands
of iterations, this spares a few cycles and allows other work to take place
without the sometimes irritating window focus changes.

Inserted some exclusion code on the midi signalling not to dispatch callbacks
for physical midi events, nor forward them, during some critical code sections,
notably starting and stoping emulators. Also had to clean up some deallocation
of the voices as there was a 'hole' in the code where a NULL baudio would
prevent a voice from being freed up, ever.

Added some NRP commands to request remote event forwarding. This is used by
the GUI to prevent the engine from duplicating events into two possible TCP
pipes (dual manual keyboards), and by the GUI to selectively do the same for
its interfaces. This resulted in changing the -forward flag to be a global
engine setting, -localforward for the GUI to the engine (local in the sense
that the GUI is per definition local, the engine may be remote), and then a
-remoteforward option for engine to GUI settings. The latter two will only
affect the single emulation which means some GUI can request copies and others
decline them. This flag does not affect the existing -tracking option which
simply governs whether the GUI keyboard will respond to MIDI note on/off
messages. The forwarding of events covers more than just note on/off, most
notably program change and modulation events are needed even if tracking is
turned off.

Fixed an issue of incorrect shadow rendering from resizing withdrawn panels.
When they are finally exposed the shadow contained the unsized instance.

Fixed two issues with the bassmaker operation, the first step after pressing
start was not being sounded and LED status is not cleared on restart. The LED
status of the last Stop point was not being cleared. Additionally the shadow
rendering was faulty when panel selection changed with resized windows.

Cleaned up a compilation flag that could still cause it to fail if Jack was not
included in the system or build process.

Reworked the audio library so that ALSA devices are just drained and prepared
when a read or write error occurs. Previously they were closed and reopened
which is a rather ugly overhead, plus there were obvious chances that it used
to incur some memory leakage. The new code changes some of the data preload
processes which now have to be pushed down into the library. The previous
method can still be compiled by giving the --disable-drain option to the
configure script for cases that give problems with the new method.

A failure in limits checking lead to a potential memory corruption issue in the
continuous controller code and NRP handling. This could have been the cause of
the original issues reported around NRP causing the engine to fail. Irrespective
of this, though, there are too many possible collisions here as the NRP address
space is common across a given MIDI channel making its use rather hazardous.

A couple of the emulators were exhibiting fairly random segmentation faults,
indicative of memory corruption. Ran up valgrind to give some input into the
causes and there were diverse issues that had to be taken care of. A part of
the cause was the controller ID damages given above, there were diverse changes
to the emulator code as there were a few errors in buffer pointer management
that resulted in some emulations leaking quite voluminous amounts of memory
each time they were invoked, and some small leaks on things like audio device
restarts where buffered name space was not being reutilised. There was one
case of a bristol audio structure being reused after it had been freed, this
was introduced when the emulator destruction code was moved from the MIDI
thread to the audio thread for other unrelated problems. Valgrind still reports
some minor memory leaks however these are almost uniquely related to the ALSA
library interfacing where structure ownership is not really that clear and are
typically bits of memory that are not really lost, they are just not freed on
exit, and since the audio drain feature was added then the audio device is not
longer reopened when xruns occur. These remaining bits can be reviewed later
as the loss is still small, it does not appear to increment over time and does
not affect functionality yet. In total there were about 15 changes related to
corruption rather than leakage although not all of them would have caused
segmentation faults as they were not all write operations, some were read.
These would have caused intermittent noise (ticks) and potentially wild
modulation, especially of the DX FM operators.

Removed an issue with the libbristolmidi ALSA SEQ interface handling for the
channel identifier, it was not correctly being merged across resulting in all
channels converging onto zero.

There was a small timing window where GUI failure could result in dangling
emulators (headless). Active sense will only start after a sense message is
received, so if this first message does not get there then the emulator does
not detect GUI failure. The engine now always starts ActiveSense, the GUI
has to turn it off if not enabled.

There was a ludicrous amount of debug messaging added to track down all of the
above problems and rather than remove it all for the release, they were buried
under a -debug flag that defaults to 'off'. Values of '-debug 12' or greater
are not advised as they will debug every period of samples.

The B11 library stops key repeat on window entry and reenables on LeaveNotify,
this is use to make sure the QWERTY keyboard tracking functions as expected.
With some window managers (reported against fvwm) the window Destroy function
only sends a wmDelete request and no LeaveNotify as the window exits which
would result in loss of key repeat. The command 'xset r on' fixes that however
submitted a fix to turn repeat back on under these circumstances too, and added
in some X11 event debuging at -debug 9 or higher.

Finally continued to resolve what I would call minor issues although that is
subjective. Engine compilation did not include config.h, the Solina had very
different gain on its harmonics, some of the bitmaps needs improved drop shadow
rendering, the MIDI processing would terminate with the first emulator to exit,
ie, the MIDI library was not reactivated, etc.

Removed potential segfault in midiNoteOn(). Put the speaker holes back into the
ARP 2600, vertically as there was a shortage of realestate but having them puts
the gravity back into the image.

Fixed an issue with the flagging defaults for the -alsa flag, it was taking
ALSA rawmidi rather than the usual target of ALSA SEQ. This would fail the
option completely. It could still be made to work with -alsa -midi seq, or by
not using any specific driver options as the defaults were correct.

Updated diverse parts of the GPL compliance, bringing all the files up to
version 3 of the license and including the disclaimer events where necessary.

Bristol version 0.50.0 was never distributed, the release was rolled up into
0.50.1.

    0.40.8 22 Jan 2010 Maintenance release

Fixed an issue with the flagging defaults for the -alsa flag, it was taking
ALSA rawmidi rather than the usual target of ALSA SEQ. This would fail the
option completely. It could still be made to work with -alsa -midi seq, or by
not using any specific driver options as the defaults were correct.

Jack MIDI opening sequences had a potential window to fail in which case the
interface would not be activated.

There are no further fixes from 0.50.1 that will be ported back to 0.40.8 as
they are now primarily related to new features in the 0.50 stream.

The 0.50 stream will also be created at the same time, as such this download
may not be of interest to many people, ie, installing this may duplicate the
effort later.

    0.40.7 22 Nov 2009 Maintenance release

Fixed some compilation flags that could still cause the build to fail if Jack
drivers were not included in an installation. This is a backport from 0.50 for
compatibility purposes.

The sid.c code had as issue with debuging being executed without suitable
checks on the handle. Could cause a crash which has now been fixed.

The XPM reader had a couple of issues with parameter naming collisions and its
file naming for temporary files used for decompression could also fail if more
than a single GUI intialised at the same time.

Had to implement some extra local memory sanity checks before calling the
emulator operate() code. Depending on timing these may still be null as the
emulator initialises.

The bristol BassMaker would give incorrect panel rendering when panel selections
were made on a resized window. This could have affected other emulators as well.

The BassMaker would jump the first step of a sequence.

The BassMaker did not correctly clear the LED status of the stop position.

There was a hole in the voice management code that would prevent a voice from
ever being freed up if it had a null baudio. This could happen if a voice is
still active as an emulator is terminated.

Cleaned up a compilation flag that could still cause compilation to fail if
Jack was not included in the system or build process.

A failure in limits checking lead to a potential memory corruption issue in the
continuous controller code and NRP handling.

Removed an issue with the libbristolmidi ALSA SEQ interface handling for the
channel identifier, it was not correctly being merged across resulting in all
channels converging onto zero.

A couple of the emulators were exhibiting fairly random segmentation faults,
indicative of memory corruption. Ran up valgrind to clear up a few memory leaks
of small amounts of memory on things like audio device restarts and also to
track down the corruption. It was partly the controller ID damages given above
however the baudio structure was getting freed before its ultimate use which
could intermittently lead to further damage. There are still some minor memory
leaks however these are related mostly to ALSA library interfacing where
structure ownership is not really that clear. This can be reviewed later as
the loss is still small and does not affect functionality yet. In total there
were about 15 changes, not all of them would have caused segmentation fauls as
they were not all write operations, some were read. These would have caused
intermittent noise (ticks) and potentially wild modulation, especially of the
DX FM operators.

The B11 library stops key repeat on window entry and reenables on LeaveNotify,
this is use to make sure the QWERTY keyboard tracking functions as expected.
With some window managers (reported against fvwm) the window Destroy function
only sends a wmDelete request and no LeaveNotify as the window exits which
would result in loss of key repeat. The command 'xset r on' fixes that however
submitted a fix to turn repeat back on under these circumstances too, and added
in some X11 event debuging at -debug 9 or higher.

Removed potential segfault in midiNoteOn().

    0.40.6 28 Sep 2009 Maintenance release

Resolved a name resolution issue that would cause the split/layer keyboard
emulators to fail. The dual manual ones should have worked. The workaround was
to default the hostname when null but the actual fix is to request the same
destination host in all cases, something that will now only go into 0.50.

Included some memory packs for the trilogy and polysix emulators.

    0.40.5 23 Jul 2009 Distributed processing maintenance release

Added an option to startBristol, -gui, which will prevent the GUI from being
started and invoke the engine with all the resolved bristol variables. This
will allow for easier distribution of the applications with GUI and engine on
different hosts which was always a part of the design but was never really made
that accessible. This can be used in conjunction with the -server flag which
will leave the engine active even when the last emulator has disconnected.
Running as a server lead to a few issues that were anticipated - constantly
reconnecting GUIs would exhaust various engine tables that were not being
cleaned up correctly as this had never been widely used. The file descriptor
table was not being cleaned up, the handle and device tables similarly. There
was an issue with SID selection of the EXIT requests not being correctly matched
causing the wrong emulators to be disconnected, and with failure to correctly
close input file descriptors on active sense failure requiring a small change
to the device reading logic. It was finally possible to run a test script to
reconnect nearly a thousand times, without failure, all emulators still audible
and so moved to released code.

Several issues arose whilst building the application without ALSA drivers. This
is supported, especially now that Jack MIDI is integrated, however since ALSA
turned 1.0 the coding has been a bit lax, assuming that ALSA was available and
integrated. The result was that building without ALSA might fail and that even
when compiled there were issues with device open() requests. Resolved these and
added the flags required to accept note events over the control link so that
GUI keyboard events are still tracked even if the ALSA code is not integrated.

Was requested to remove all OSS dependencies from the build process as well.
This was a little more work than ALSA since that was always intended to be a
build option, OSS by contrast was always anticipated to be present. Had to
clean up some of the socket toolkit header files and some erroneous definitions
in the midi library that was being flagged by some more meticulous compilers.

Reworked the TCP addressing code to accept -host <hostname:port> where hostname
can naturally be a IP address or (non)canonical hostname. The port option can
be used with the -engine flag to connect the GUI to a specific host where the
engine is running, remotely: it is an alternative to the -port flag however
it is still advised to actually use -port for other reasons.

There was some general code cleanup from the request to have bristol function
on a system that had neither OSS nor ALSA installed. This was never anticipated
and making it possible brought other issues to light.

The Trilogy had a very unequal mixing section, the organ gain was too quiet
and the synth section too loud. These were evened out.

The Trilogy also had some rather unusual use of volume controls. To reduce
CPU load the synth would not run the organ and string sections unless they had
a non-zero gain. This achieved its affect however the result was that if the
gain was zero at note_on then the voice was always muted (it actually just fell
through the note logic and turned itself off). The fix was to always run the
oscillator divider circuit envelopes under all circumstances to engage the note
logic. The audio generation code is still skipped as it would be silent anyway
when the gain is set to zero.

    0.40.4 06 Jun 2009 Audio Driver Mainenance Release

Added an autodetect for Jack where a small program will connect to the daemon
and find out the sampling rate and period size. These are then given to bristol
as parameters preventing unexpected mismatches later.

Fixed a watermark issue with the ALSA drivers, the high available threshold was
too low which causes the library to report false overruns. Since these come
back as a failed write operation the bristol audio library was restarting the
audio devices. The diagnostics reported this as a broken pipe.

Resolved a typo in the ALSA drivers that damaged the periodsize and buffersize
matching. Caused cyclic ticks in the output stream depending on hardware and
ALSA driver versions.

Changed the activesense period to 3s and timeout to 15s. There are issues when
running with RT scheduling where the GUI may get starved when there is a lot
of audio activity causing the engine to give a false positive of a GUI failure.
Since active sense is really there to make sure everything exits gracefully
when there really is a failure then the timers need to be more flexible to
cater for situations of high CPU load. [0.40.5: as a side note, this only
really affected a system if it had cpu-speed ondemand, or was massively over-
loaded, neither of which are optimal for audio processing.]

    0.40.3 25 May 2009 Maintenance release, B3 stuck notes.

The Bristol B3 was exhibiting stuck notes, fairly arbitrarily however the
issue was not reproducable on the development system. After a ludicrous number
of debug builds to get different statistics the cause turned out to be the B3
postOpts which manipulated the voice flags and the resolution was to extend
the semaphore coverage to include emulator postopts. Theoretically it would
be possible to have just changed the B3 code however the engine that hosts
the emulator should not be open to flag abuse in the voices and the voices
are allowed to manipulate these flags. The actual cause was a race condition
that only really exhibited itself on multicore/HT systems.
Thanks to Andrew Coughlan and Damon Chaplin for the report and debuging
output to isolate this issue. As the problem was not reproducible on the
development system (single core) then tracking down the cause required a
number of different debug revisions and a great deal of patience and output
logging from the people involved.

Releases 0.40.1 and 0.40.2 will be removed from the download site.

The bristol shutdown procedures were not really compliant with the Jack API
definitions, they would not deactivate/unregister the active handles before
exiting. This does not work very well with multiapp environments, it causes
a subgraph timeout in the API. Changed the shutdodwn code sequences so that
the last exit operation will clean up the emulators in the audio thread and
let the MIDI thread then unregister jack and exit so that all parties are
happy. Also added some diagnostic output in the event that ports cannnot be
registered - this happens if Jack has a lot of application ports to deal
with so the additional message makes sense. Also coded in jack_client_open()
to replace the now deprecated jack_client_new() previously being used.

The Sidney emulator was about 1/2 a semitone out. After a lot of delving into
the correctness of the code without much success (ie, it seemed correct) it
turned out the C64 had different versions for NTSC and PAL, with different
CPU clock speeds. The frequency tables were built from data taken from what had
to be a confused manual since they did not match up for the clock speeds. When
the due correction was applied (0.985 to 1.02 and finally 1.023MHz) it was
finally pitched correctly.

The trigger events for the SID MOD Env were not really correct. Any accepted
note_on event would cause them to trigger however in light of the way voice
separation happens it really required that the Env was only triggered if it
would have a affect on the given voice. There were a few cases, voice goes
via the filter and env modulates the filter or if the Env modules the voice
that is being activated. Added the logic. Voice-2 arpeggiating never triggers
the envelope, only its own envelope.

Increased the minimum Sidney arpeggiation step, it was a ludicrous 0.3 ms, it
is now a more reasonable 16ms. Maximum stays the same at roughly 250ms.

The Sidney emulator had an issue with some memories and its keymode settings,
the indexes were not converged correctly resulting in the radio buttons not
working normally (double selected radio buttons).

The OB-Xa 4-pole filter was incorrectly mixing its feedback loop, silencing
the output signal. The 2-pole worked correctly.

The MIDI library was altered such that all messages now carry a sequence
number, it's only u32 but its only use is debugging events and with the typical
event rates this will last far longer than any session. Also finally fixed the
event timestamps which were previously just null.

The midi and audio threads had different scheduling algorithms, one was FIFO
the other RR. Since the two threads used semaphores for a critical code
section for note events then there existed the possibility that the midi thread
could cause large delays to the audio thread by taking the semaphore and then
getting pre-empted. The fix was pragmatic, both thread have been made FIFO
with different priorities. A full fix would also have been to adjust the
thread priorities in the critical code however the current fix works except
when there are multiple RT programs running and that should only be the case
if they are all audio threads.

    0.40.2 05 May 2009 Maintenance release, usability improvements.

This is primarily maintenance for the last couple of releases including fixes
to the SID emulator and some ARP improvements.

The SID synth has more key assignment modes, both arpeggiating, visible in the
GUI as Arpeg 1 and Arpeg 2. They will split the keyboard at MIDI note number 52
then assign two voices to one half and one voice to the other. Arpeg-1 has its
function on the upper half, leaving the lower half as a duophonic synth
allowing an arpeggiated chord as rythm for a bass sequence. Arpeg-2 will do the
opposite, it will arpeggiate on the lower half allowing for arpeggiated rythm
with a duophonic lead solo. These were seen as an improvement over the previous
but the results need to be reported back.

Bristol will now check the system for the availability of the TCP control port,
defaulting to 5028. The application behaviour has always been that an engine is
attempted every time the application starts and correctly speaking if a user
wants to work multitimbral then the second request should be given the -engine
option. Without this flag it still worked but was sloppy, the second engine
would fail to get its control port and so would exit, the second GUI would
still connect to the first engine and start a second emulator. The current
behaviour is that each time the application is started it will look for the port
availability and if it is already taken then an upwards scan is done from the
port number looking for a free socket. The port can be specified explicitly
with the -port option if fixed ports are required however this is not a real
requirement if the -audiodev is used with Jack, for example, to specify the
registration identifier for the new engine. If no engine is requested the GUI
will just attempt to connect to the specified port although arguably it should
check to see if the port is open - this is kind of done implicitly when the GUI
attempts to connect to the port.

Extended the BRISTOL_AUTOCONN by adding the following environment variables,
BRISTOL_AUTO_LEFT, BRISTOL_AUTO_RIGHT and BRISTOL_AUTO_IN. If these are set
they will be searched in the relevant ports list and then connected up. This
only happens in conjunction with AUTOCONN. On my systems this was tested by
setting them to system:playback_1, system:playback_2 and system:capture_1
resprectively, and by leaving them unset. Will see how much use they are,
since they are environement variables then to be useful they would have to
be scripted.

Submitted code to repaint transparency layer devices when windows sizes are
changed. This affects shadow layers and transparencies (such as the ARP 2600
patch cables). Prior to this the objects painted on to this layer were lost
which was confusing with the ARP at least. The effort to do this was considered
preferential to the alternative which was to fix the window size once defined,
not allow resizing and just have the -scale option at startup.

There were some compilation issues due to the SID test program not having the
correct dependencies. Removed sidtest from the distribution, it is no longer
required, it was only used to exercise the bristol softSID chip until it was
integrated into an emulator, now done.

Known issues are that the Pro-10 would fail on some systems. This is a very
specific issue as some systems have been reported not to suffer from the
issue. A workaround is in place however a longer term resolution will have to
be sought and a bug is open against the issue.

    0.40.1 25 Apr 2009 Commodore C64 SID emulator

This release introduces an emulator for the Commodore C64 6581 SID audio chip.
The implementation has a digital access method to program the chip registers
and an 'analogue' access method to extract the audio signal. The oscillators
and envelopes are implmented with integer functions as the original was partly
digital, and then the filters are in floating point to emulate the analogue
components. Specifics of the chip will be in the README file presently.

Two of these chips were then used for a bespoke synth, the -sid. This is not
based on any original design but exercises the SID emulator. One of the two
chips gives the audio output, the second gives signals for modulation: one
LFO, one Env and one noise source which can be as an input to a S&H circuit.
This design uses a few different voice allocation routines, monophonic, three
voice polyphonic plus some combination algorithms to give access to the high
frequency arpeggiation used often in the C64 where a single voice would do a
fast scan of several frequencies to give chords and widen out the sounds. Each
of the three voices can be programmed independently.

Added an environnment variable, BRISTOL_AUTOCONN, which when set will direct
the jack library to autoconnect its ports to the first IO found. This will not
be much use for general users however it will make testing easier.

Fixed an issue where the emulations would fail unless started on midi
channel 1. The issue was caused by the Globals settings using a system
connection id rather than the negotiated midi channel for setting up
diverse defaults tables.

    0.30.9 02 Apr 2009 Bristol BassMaker, massive filter optimisations.

Coded a 16 step, 4 page sequencer along the lines of the SQ-10 to generate
bass lines, hence the pun. The overall feature set it pretty sparse since this
is not intended to be a general purpose sequencer. Each step has a note,
transpose, volume for the MIDI note and a Control option to send fine tune,
mod or another MIDI note on a second channel, plus the triggers can be skipped
to join notes. The control features have not been widely tested and may need
some fixes. Also the fine tune and glide when applied to the Control setting
are a little dependent on the emulator, something that can be altered if the
is a demand. A full description is in the README file.

Colin Fletcher optimised the huovilainen filter code, first factoring out kfc
to reduce the number of multiplications being executed, then continueing with
completely factoring out v2, and since it was generally used as a divider
function this was a considerable CPU overhead. This delivered a massive
improvement in the CPU utilisation, not only of the filter but the emulator
generally due to the filter being so CPU intensive. The factoring out of v2
was ingenious since it was not immediately evident from the code that this
would have been possible.
Testing this also corrected some anomalies in the OBXa filter selection code.

About 5 superfluous variables were stripped out of the filter code to reduce
parameter popping and actually improve readability providing minor improvements
in the filter efficiency.

Applied noise injection code generally to prevent filter denormals with low
to zero input signal. This is quite efficient noise generation code so should
not have a big affect on the optimisations and prevent 100% from denormals.

Another optimisation was applied to the filter for higher sample rates which
removes the internal oversampling. At the higher rates this delivers around 40%
reduced load and should not result in any loss in quality since it only applies
when playing at 88kHz or greater where the filter response is still good to
over 20kHz without resampling. Not all the emulators will actually use this
code modification since it is only in B_FILTER2 which is sparsely deployed at
the moment, something that will change as the different modifications are
qualified. The result of all these optimisations is that this filter code
should be about as fast at 96kHz as the previous one was at 48kHz, and as the
filter code currently uses the vast majority of the emulator cycles then it is
probably possible to run any of them now at the higher sample rates with
little affect on net load.

Applied some reduced EQ to the Hammond B3 Bright signal levels. This kept the
same rough profile however the overall signal level was far in excess of the
existing normal gearbox. This was required due to some big reductions in the
crosstalk levels of the normal gearbox leaving bright as too loud. The changes
to the crosstalk was required since the net amount was superfluous and
although it brings some nice overdriven sounds it was excessive for both of
the configurations to have that amount.

Bristol no longer implements any Jack port auto-connect per default. After a
trail of submits to LAU there were very good arguments as to why having
default connections always being applied is a dangerous feature. The auto-
connect remains but has to be requested with '-autoconn' although admittedly
this does make it a fairly superfluous feature.

The VOX Continental M2/Super/300 was silent. The global parameters page had
zero set for all parameters that needed corrections to the memory loading code
to force the save settings into the active set.

The Polysix emulation would clip excessively with the modgroup was routed
fully to the VCA. The signal gain from the LFO would result in an overdriven
output. Reduced all the respective output stage signal levels, which are still
quite strong anyway, and also some of the tremelo depth when mod routed. This
will have a minor effect on some patches.

Incorporated Andrew Coughlan's manual page for the Polysix emulator.

    0.30.8 20 Mar 2009 Maintenance release, ARP 2600 fixes.

When using Jack as the MIDI interface it was possible that the engine would
attempt to link audio to midi channels and vice versa. The requests fail and do
not break anything but the default connections don't work so its not quite as
plug-n-play. Added code to check for the port name and also to parse the whole
list of outputs for the first two that will link up, similarly all the inputs
later.

Resolved a strange issue with the ARP 2600 with respect to discrepencies
between the GUI indeces and the engine indices. The problem did not show up
on all systems and the root cause was being masked by a programming error in
the engine using an incorrect scaling for parameters passed to it. The problem
was not evident on all systems probably due to differences in type casting -
the parameter is delivered as a float however the index is taken from that
cast into an int with a range considerably wider than '1.0'. The fix also
required changes for removing cables.

The ARP 2600 filter and amplifier outputs had a signal level far stronger than
most of the other components, this came from reworking the general filter
input/output levels to ensure it was being driven correctly. Added in a bit of
normalisation code to even the levels up.

The ARP 2600 filter would also suffer denormals if all the inputs were move to
zero. Almost to be expected due to the DSP involved in the filter. The initial
fix is to inject about -96dB of noise if all the inputs sum to less than that.
This has the nice side effect of making the filter self oscillating at high
resonance, that was not previously the case.

Reorganised the ARP 2600 volume options. There was a single 'Global Volume'
that just drove the output stage. This was broken in several ways. Firstly it
was in the memory which was a mistake to start with. Then it did not function
as per the original where this single control was called 'initial volume' and
was a kind of drone level for the VCA. To correct this the parameter was
separated into 3 controls: Global Volume which is not in the memory, Program
Volume that is in the memory, and Init Volume to allow the VCA to drone. It
is noted that droning in polyphonic mode is messy however not having it with
mono mode did affect capabilities.

The BME filter tracking keyboard selector did not function to expectation, the
tracking was either off, or honoured along with the mod group which was wrong
as these are exclusive options.

The X11 library will now only handle single configure events at a time. These
are typically window resizing that come by the boatload due to mouse motion
and if they are all handled at once we tend to get active sense failure and
the engine (then the GUI) exiting.

Reduced the B3 drawbar crosstalk values for both gearboxes. The previous
values worked but the signal to noise (crossbar leakage) was excessive. The
bright gearbox settings are still quite rich in harmonics giving a reasonably
overdriven signal but the normal gearbox is now not so noisy.

Distributed Andrew Coughlan Polysix patch 23 and added his sample to the
website.

    0.30.7 02 Mar 2009 Baumann BME-700

Build a BME-700 emulator. This is a rather rare synthesizer and is probably
the best example of where an emulator makes sense, it would be pretty much
impossible to get ones hands on one of these. The emulator is in its first
build and the oscillator may well need some improvements. Future work will
also improve response with higher samples rates by removing the internal
oversampling code. To test this emulator try the options
    startBristol -bme700 -mono -hnp -retrig
This will give a monphonic emulation with high note precedence and envelope
retriggers for any note change.

Added a velocity flag to the monophonic key logic such that velocity may then
optionally only be taken from the first note in a legato sequence rather than
from every note in the sequence. Option is called -lvel.

Monophonic triggers were a little broken, the current fixed code will either
always send a retrigger when the voice moves to a different note with the
-retrig flag or will only send a trigger for the first of a legato sequence.

The Korg MonoPoly emulator would crash. The new synchronisation code did not
check for a null sync buffer and some of the emulators would pass a null
buffer if sync was not configured. Related to this was reassignment of the
-mono switch to be 'monophonic', equivalent to '-voices 1' rather than as an
acronym for -monopoly. The switch was reassigned to make the monophonic note
logic more sensible.

Prophet bank select was broken, code was adding incorrect offset into the
selection algorithm.

    0.30.6 22 Feb 2009 Monophonic note precedence key logic.

The note assignement logic now correctly implements/emulates a monophonic
keyboard with low note precedence (-lnp), high note precedence (-hnp) and last
note precedence. Previously there had only been code for last note - it was
the polyphonic algorithm with just one voice however this gives a completely
different playing style. The option only works when the voicecount is set as
a single voice. Additionally there is a -retrig option to trigger in both
directions when playing legato style. The code is interesting since it was
firstly a little awkward to do and also since the final solution was to have
the monophonic synth start playing its single voice and then just keep the
voice rolling forever. It stacks up the CPU constantly but gives some useful
features with the ARP 2600 and Moog Sonic-6 (and others) for droning or just
tweaking them without playing and is arguably a closer emulation of a real
mono synth. The voice, once assigned to a mono synth, should not be preempted
by other emulations, ie, it becomes dedicated.
A present release may make hnp and retrig the defaults for mono synths, and
similarly invoke a single voicecount if precedence is requested. For not you
will probably want to use -hnp/-lnp and -retrig to get useful results.
This release might include some monophonic note logic debugging output, it
will probably stay there until 0.30.7/8 depending on testing or bug reports.

Finalised the frequency/step tables and moved on to implementing glide for the
non-resampling oscillators. The oscillator already supported this but the
frequency tables were needed to correctly fill the buffers. Poly-800 parameter
#67 now controls glide for that emulator, previously not operable.

Reworked all the filter code keeping only the Chamberlain and Huovilainen. Then
reworked the Huovilainen for 2pole/4pole (non-resampling versions later). Put
in an Oberheim modification that remixes the different pole outputs back into
the main signal path. The mix is configurable however the GUI has no control
that drives it: a default value is taken. The filter is a bit richer for the
mix. This mod was at least considered by Oberheim for the Matrix-12 but then
never implemented as the discrete circuits with quality components was a bit
cost prohibitive. Here is is relatively simple work and since the filter is
already computationally expensive this operation does not add much to the CPU
requirements. Different codes sections use different mixing loops. The main
one puts the tapped signals into the output stage only, others will mix it
back into the filter feedback loop which give yet another quality however it
also suppresses resonance due to the resulting phase complexities.
[As a note, the application still implements 3 other filter types, the rather
weak rooneys and a butterworth. The ARP also has its own lag filter for
voltage processing.]

The Arpeggiator/Sequencer code would leave voices hanging after the operation
terminated. This was kind of known, start/stop just set the emulator flags to
allow the code to be called. The resolution was to actively deschedule all
voices associated with the arpeg/seq function.

The LFO changes to 0.30.4 to increase the maximum speed did adversely affect a
number of memories and, rather than back them out, this version introduces
parameterisation to set the upper and lower limits of the LFO with defaults
that were as per 0.30.3 and below. The new emulators that want to use LFO up
to ranges that verge on FM functionality will request wider ranges. The
default values should go from 0.1Hz to 20Hz in line with the previous releases.

Build options was damaging the LD_LIBRARY_PATH where jack libs were included
before the newly built library path. The result was that rebuilding the code
would probably find the installed libraries rather than the new ones.

The Hammond was loading excessive memories on switching the opts panels in and
out, added some flags to prevent this.

    0.30.5 01 Feb 2009 Maintenance release?

Worked on a slew of new (short) recordings for the website, fattening out a
few of the exising memories. This lead to some issues with sound quality in
some emulators. These would have been fixed earlier if I actually used bristol
however most of the work is in development rather than operation. Most of the
sounds were configured in a matter of minutes, more work would have improved
the depth but they give an idea of each of the emulations that were recorded.
These short recordings highlighted a few anomalies in the code, and along with
some other issues that have been gathering over a few releases the rest of
this release is a set of fixes.

There were apparant envelope clicks on the axxe emulation, primarily on note
off events. This was due to a direct 'gain' level being mixed in with the
ADSR. Corrected it with a grooming envelope on the key however the ARP lag
processor would also have done this trick quite well.
Applied the same change into the Odyssey as it uses a similar gain section on
the amplifier. The 2600 is not affected by this since it uses patching to get
around the amplifier rather than fixed signal gains.

PWM on the Arp DCO was failing, affecting all the Arp emulations. The cause
turned out to be a mixup with the min and max limits for the pulse width,
something that was introduced when the corrected sync code was introduced in
release 0.30.3.

Fixed a key mapping issue where the '\' character mapped to key id zero rather
than two semitones above the ']' key where it should really have been mapped.
The changes are in the text profiles so could have been done locally in the
event of complaints. Apart from that the mappings only cover a US QWERTY
keyboard anyway.

Some of the keyboard graphics were damaged during the redesign for the
Poly-800 giving incorrect redraws for the 3 octave emulations.

The Poly800 GUI had a typo that stuffed a non-zero termination signal level
into its DCO-2 envelope causing clicking if Double was selected. A separate
issue occured with the filter envelope that was not retriggering correctly,
resolution was to configure this one envelope for re-zero and will have to
see if it needs to be done for all of them.

The duplicated raw audio output code does silence suppression however this was
only intended to be for leading silence. It was implemented as a cheap way to
get sample for the website but it was doing permanant silence suppression which
damages the audio in most cases.

Added a -mbi option and structure entry to the GUI for memory supersets that
came as a side effect of reworking just some minor details of the polysix
options (the -load worked however the GUI did not reflect the true memory).
This was rolled into general use however some emulations already use local
methods to manage this. This will only conflict if the global method is
requested and it also affects Chord and Sequence memory as that does not
access this parameter (yet). This is a single digit parameter adding that
number of K to all memory access. Memory #1 with '-mbi 2' accesses memory
#2001 on disk. The option is additionally set from the -load setting, if a
memory above 999 is requested then mbi is stuffed with the most significant
part and the memory index is the remainder.

Revised the LFO to have a range from 0.1 to 100Hz for a pending BME emulation.
The rate control is a power function so it should not affect any existing
memories excessively.

Broken in this release and until further notice is the -glwf option, it causes
note vocalisation errors. The -lwf option should be used with each emulator to
activate the lightweight filters individually rather than globally.

    0.30.4 20 Jan 2009 Korg Poly-800

Built a Korg Poly 800 which was more work than anticipated. The GUI needed to
have a 'membrane' support for the parameters which generally takes quite a lot
of effort, perhaps less since the bit-1 already had much of the code. Another
envelope was built as it is a 6 stage design however that is reusable for the
pending Yamaha CS-80 that has been under construction for a while. The Poly800
emulates all the dual/single oscillator with an envelope each, plus the single
filter design was integrated into the emulator PostOps() routine as well as
the Poly code so that there can be a single high key tracking filter as per
the original design or you can have one per voice as a bristol mod. The full
set of mods and general construction are described in the README file, the
only remark here is that the single filter code is a bit jumpy when the notes
change by large amounts, something that could be improved.

Added modifications to the bitone oscillator such that it integrates a separate
sync output. This is at the base frequency with a resampled squarewave only,
allowing this complex oscillator to still drive sync into other oscillators.
Tested with the Crumar and Jupiter emulators.

The same modifications were rolled into the explorer DCO since it also
generates some combined waveforms that could distort the sync algorithms.

Reworked the bitone oscillator to generate what I am for now calling waveform
tendencies. The output signal will tend towards a target value under a kind
of discharge circuit at a controlled rate. The result is a non-resampling
oscillator, more or less, the wave is generated based on algorithms rather
than wavetable resampling. The results are at least harmonically unique within
bristol, at the moment only integrated into the Poly-800 emulator. They sound
reasonable when heavily filtered, a little raspy otherwise. The nice thing
is that they are still quite efficient (will change as the waveform heuristics
develop), costing only a few percent for the generation of 8 oscillators each
with 8 strands of tendencies, all slightly detuned from each other to give a
quite rich result. The oscillators can generate square, ramp, saw, tri and sine
with support for PW/PWM of the square, sync in/out on ramp/saw/square/tri.
The triwave sync is correct softsync, the rest are hardsync with waveform
inversion as required. The efficiency lends itself to oversampling which in
turn could make the Huovilainen oversampling filter more efficient and give
a net improvement in the sound at very little cost however that is FFS and
will not be done until after the P800 is released.

Integrated a new noise generator which has better performance and also a cleaner
overall signal. The previous code has some excessive LF components.

The Preacher gearbox was a sixth out of tune, 8 semitones. Pretty strange it
was not reported and I admit I had not noticed it. The default gearbox seems
to take the wheel indeces from an incorrect starting point. This also brought
to light another issue with the same code. Since the user profiles were
enforced recently then the tonewheel mapping file had to be in ~/.bristol and
was not shadowed back to /usr/local/share. This would have caused some issues
with the tones rather than the frequencies.

Built another set of keyboard layouts, this time for the Poly-800 but may get
rolled into other emulators later.

Check Button devices would still dispatch an event if the mouse is released
outside the bounds on the device. This should not be the case so checks were
added for limits before callbacks are made.

There was a small window when killing the app during initialisation could leave
the engine waiting for the audio thread forever. It should all exit so added
some timeouts to the status polling routines in the midi thread.

Key bindings were not being read for library testing. Not an operational issue
however it needed a fix for testing purposes at least.

The pitchwheel and its associated Registered Parameter were not working in
unison, had to reorganise their internal variables and the frequency calc
code when changes are made.

Reworked a few more shade layers and put the new key designs into a couple of
the other emulators.

Configure will now prompt the user to install libasound2-dev as well as
libx11-dev if either are misssing.

    0.30.3 19 Dec 2008 Crumar Tilogy, PWM and Sync fixes, Polysix improvements

Added the String section to the Stratus emulator to produce the bigger brother
of the pair, the Trilogy. As with the Organ section of the original, the string
section is not a major feature and was nothing to write home about. The code
adds some extra harmonics to fatten out the sound plus some panning and
spacialisation to enhance the section. The features can be disabled to give
a more authentic emulation of the original.

Changed the graphics on the Stratus synth waveform selector, it was not a true
mix but a three way switch. The graphic is emulated however the control is
still continuous here.

The default memory for the stratus had a bit too much key tracking configured
and it shut off the filter completely for the lower octaves.

Fixed some minor issues with the Stratus options panel.

Took excess debugging out of Trilogy/Stratus code.

Touched up the shadow layer for both these emulations.

The Polysix mg controller side affected the oscillator frequency. The wheelmod
should just affect the overall depth of the routed LFO, it was doing separate
mod for vibrato which was undesirable. Also changed the default switch for the
polysix from -poly to -polysix and -poly6. For now it will respond to both.
This was an unfortunate choice originally and will presently be dropped to
just the newer options.
Similarly changed the Korg Mono/Poly switch to be -monopoly from -mono, also
an unfortunate historical choice.

The polysix waveform selection was actually wrong regarding Square and Pulse
wave - square is a fixed wave that only uses a PW control to select its width,
the pulse wave uses the same setting but adds PWM via another LFO, these were
out of sync. Thanks to Andrew Coughlan for the insight whilst working on a Jens
Johannsons lead sound, apparantly originally done with a Polysix.

Andrew's patch also showed some issues with parameter memorisation for the
operating modes: Poly and Mono mode could be lost on reloading a memory, now
also fixed.

Added in some diverse changes for the PWM code, historically the width has
been an integer value in the range of the size of the wavetables and at least
for some of the oscillators this was still being managed as an integer. The
pulse width is now floating point and the resampling is independent of the
main waveform being generated. The difference is only subtle since the
original code resolved to better then 0.1% accuracy already however it did
show up a couple of bugs in the prophet DCO code regarding offsets and brought
to light the noise on oscillator sync with certain waveforms (notably square)
that really also need to be addressed but probably in the next release as it
really needs triangular (soft) sync as well as hard sync.

Fixed a long running issue with oscillator sync, namely that it worked but
very badly if the synchronised wave as a square. It was always ok with ramp
for example. The cause related to how sync was being done, it was just
resetting the resampled wave table index to zero, correctly speaking it needed
phase inversion as well, now implemented. The synchronising wave is also
resampled before it goes to the synchronised wave to remove the flutter or
shimmer associated with synchronising to whole samples, it basically
synchronises to subsamples. Phonically this is a big change and it may be
rolled back into 0.20 since 0.30 is still relatively new.

Alterations for this fix are still needed for bit1osc, it generates complex
waves by default and they are not very good for sync signals. For now users
will have to simplify the synchronising wave, a future release will have the
oscillator generate a sync output signal at its base frequency.

    0.30.2 15 Dec 2008 Crumar Stratus

This release has an implementation of the Crumar Status 'duosynth', it used an
organ divider circuit to produce some slightly lacking organ sounds with four
harmonics of pure square waves plus a six voice poly synth. The organ circuit
has been beefed up considerably - it can produce the same square waves however
adds in alternatives (square and sine through ramp, smoothly) and some added
stereo spacialisation. The interesting synth glide circuits are emulated, this
is not typically polyphonic portamiento since this beast used organ divider
circuits for the oscillators so independent glide on each voice was not
possible. In contrast the circuits could be over and underclocked as a note
starts then glide back to the target note, here emulated polyphonically.
All the legato features should work - the LFO in mono mode will only strike
open the LFO envelope grooming circuit once, the glide features will work in
a similar legato fashion and the oscillator output can be kind of random with
legato.

Improved the oscillator sync algorithm however certain waveforms are still
noisier than they should be. This was only in the Crumar Stratus oscillator
but the alterations can be moved over to the other synchronising oscillators
when finished.

Altered the filter keyboard tracking for the Huovilainen to try and get better
tuning. It can be made playable however that still takes quite a lot of
tweaking so a few more changes are likely over the coming releases.

Put the reverb back into the Sonic-6, will see what people make of it as it
only works well with fat sounds (B3) or at low delays.

Reworked some of the button control logic since they were not being set when
withdrawn. The logic for withdrawn should really be just 'don't draw' and this
was corrected.

Reworked some more off the graphics for better drop shadow on the keyboards.

    0.30.1 03 Dec 2008 Voyager Electric Blue, Moog Sonic 6.

Voyager Electric Blue released in conjunction with some fixes to the existing
explorer algorithm as detailed below.

Moog Sonic 6 released, the suitcase synth. There are diverse differences with
the original, implemented largely because they were denoted at the weakest
points of this fair synth:

    Added a mod wheel that can drive GenX/Y.
    PWM is implemented on oscillator B
    Installed an ADSR rather than AR, selectable.
    No alternative scalings - use scala file support

The emulation is not duophonic. Primarily poly with separated glide. It does
have the same 'diaphonic' capabilities although they were pretty dubious in
the original. Details are in the README file. There are sadly few memories
configured in this first release, none in fact.

The Sonic-6 implementation was the first new algorithm in a while and it has
shown a few issues with gain levels regarding the filter output. This lead
to a few more alterations to the normalisation of diverse emulators but it
should fix the issue of filter resonance overdriving the outputs and causing
clipping. It should now be a gentler easy sine wave, probably still quite
strong but it should not cause clipping with most emulations.

The Explorer code needed to be reviewed for a changed filter set and filter
characteristics, the original stacked LPF was wrong. The code needs to have
either serialised HPF/LPF or parallelised (and then stereo) LPF. This was
worked into the code and an interface put together to emulate the 'Blue Ice'
version of the synth.

Reworked the Release parameter of the Voyager/Explorer. The existing code
either configured the value or just '10' depending on the release switch. The
correct coding is to either send the value or a small part of the value based
on the switch setting, closer to the original.

OSS drivers were broken due to a failure to convert some of the device flags
correctly. The result was no subfragmentation and no subfragment buffer. Only
tested with ALSA compatibility mode.

Reworking the drop shadow step by step on the piano keyboard. Gives a better
effect.

Minor changes to the options for the different Prophet emulators.

The 0.20 stream is now maintenance only.

    0.20.10 27 Nov 2008 Maintenance release.

Altered the permissions on the memory files and pixmap files since some users
would have had problem accessing them. That would have made memories
unreadable and given some incorrectly painted images. There were no complaints
however it probably would not have been totally obvious what the problems
even were.

OSS drivers were broken due to a failure to convert some of the device flags
correctly. The result was no subfragmentation and no subfragment buffer. Only
tested with ALSA compatibility mode.

    0.20.9 14 Nov 2008 Maintenance release.

Changed the lightweight filter option to be emulation local rather than global
but kept the global option now as -glwf. This allows for mono lead synths to
have a thick filter and the rest to have the lower cost Chamberlains.

Added an option to prevent the user interface from requesting window sizes to
the window manager by default used to ensure that the aspect ratio was some
kind of reasonable match to the original however this causes problems with
some tiled window managers causing endless redraws. The -ar or -aspect option
will just make the library paint into whatever available space is given to the
GUI - the results may look gruesome if either the height or width is excessive.

Added code to the XPM reader to look for *.xpm.gz and then to gunzip them
first to /tmp. This reduces the installation nearly by a factor of 5 and is
minimal overhead an this is only in the startup routines. If the bitmaps are
manually decompressed then the overhead is avoided as the xpm is then found
first. It probably needs to be noted that the benefit of having the gz images
will only be seen if the previous installation is first removed. If not then
the .xpm and the .gz will remain.

Alterations to the diverse blueprints, most notably the MS-20 however since
that is not yet functional it was a bit superfluous.

The following synths still need some filter work:

        -explorer          - moog voyager. Needs more work (*)
        -cs80              - Yamaha. Needs more work (* and is unfinished)

* needs to be two separate filters, Chamberlain HP into Huovilainen LP.

Added some checks for the number of options being given to both bristol and
brighton, and if they are too few to then advise using startBristol and exiting.
The goal was to advise on what should be done if somebody just attempts to use
the binaries without the wrapping script, and since the script uses a host of
default switches it doesn't cause these messages to print.

Resolved a long running and annoying problem with closing the GUI windows -
when the close is requested from the Window Manager [x] button (typically in
the top right) the application does not exit as fast as it should. Had to set
some WM attributes and do some more checking for Client Messages. Also had to
clean up the code to terminate dual manual synths, something that became
evident once the shutdown did not require a ^C in the controlling terminal.

Improved the state logic between the threads such that if the audio thread
cannot get hold of the target audio device then all threads will exit. This
was giving problems since previously the parent thread would not exit even
though the audio thread had failed. Recovery was then a manual process. We
do not need to apply similar logic to the midi thread since if that does not
open we will never proceed to the audio thread anyway.

Known issues:
Starting two mini on the same engine will seg fault when one is closed. The
buffer pointers are cleared incorrectly. It will probably be a trivial fix: not
to free the buffers on exit. The floating buffers are little overhead and will
get reused if another emulater is started.

    0.20.8 28 Sept 2008 New filters, normalised gains, diverse fixes

Integrated the Huovilainen filters into the full set of emulators. Some still
have filter options that may use the Chamberlain however that may change by
converting the Huovilainen to a 12dB/octave option and using the Chamberlain
for lightweight filters, BP and HP:

Added an option for lightweight filters where the CPU intensive Huovilainen
are replaced by the colder but a lot less expensive Chamberlain, -lwf.

Band limited oscillators are now the default with up to 31 harmonics. The
previous geometric waveforms are still available with '-blo 0' however their
roughness was highlighted by the reworked filters. A few emulators do not use
the global wave tables and will not inherit the BLO option but they should all
use other distorts to reduce the edginess of infinite bandwidth waveforms.

Normalised the signal levels on most emulations. This was lead by the Pro One
developments since it gave a reasonable signal and was used to baseline the
other emulations.

Converted glide into a power function to give better control at low values.
Converted attack into a power function to give better control at low values.

Pitch wheel depth was half a semitone out of configured value. The default
of 2 was being misinterpreted.

Rhodes was damaged due to a conflict in operator selection since the code for
the arpeggiator was finalised. The Chorus controls would select ARPEG code and
that would eventually cause issues.

Noise was inadvertently mixed in the Mini algorithm, passing through the reused
filter buffer. Fixed this and other anomalies with mod routing.

Mono emulators appeared to drop new notes when played quickly. The actual cause
was a loose coding of the note_off logic where an off event would match any
voice on the channel even though note_on had reassigned the voice a new key.
This only happened if the note_on voice was still on the newlist waiting to
be promoted onto the playlist.

Normalised gains and integrated Huovilainen filters to other emulations.

    0.20.7 29 Aug 2008 Sequential Circuits Pro-One, Scala tonal mapping tables, overhaul of the Prophet-10

Built a Sequential Circuits Pro-1 as a polyphonic emulator. There are some
differences in operation compared to the original. Details are in the README
file.

The Prophet-10 needed some work primarily on layer management. The original
had a few features for in-memory volume/balance/tuning, a sequencer and the
memory bank functionality was organised differently. These were all worked
into the emulation. The sequencer is a lot simpler than the original but can
function with a sequence per memory and adds the ability to arpeggiate and to
chord notes. Also reorganised the 5/10 voice management since it was a little
incorrect previously and realigned the midi channel utilisation.

Reworked the hammond drawbar device to support fully painted images and used
that to render a new ModWheel dev with a rolling tooth design for the Pro-1.
It could be improved with a local highlight rather than using the global
shadow layer, something for future study.

Reworked the rotary pot to support limited motion from -60 to +60 degrees
with stepped movement for the Pro-1 octave selector. This could be used in the
other emulations however the general use was for waveform selectors and the
problem here is realestate to show the waveforms - without the full rotary
action the diagrams will not fit the available space. Mono, Poly now also use
it for octave controls and waveform selections requiring a bit of redesign of
their blueprints. Also put into the LFO waveform selection of the Jupiter.
The work also included redrawing code the complete rotary to support irregular
designs. This was required for the tip of the ProOne pot that sticks out.

Added a parser for Scala .scl files to build a microTonalMap for the synth. It
is possible to retune the synth based on the thousands of Scala maps. The
option is '-scl <file>' where the file can be a full path name (leading '/') or
if the mapping file has been placed in the $BRISTOL/memory/profiles directory
it can be a "filename.scl" or just "filename". The settings are global at the
moment and there is no default scala map although that would be possible if
people were interested, or a default per emulation for example.

Added another two taps to the Hammond chorus organised such that there is a
unique tap sweep per VC rate. Each sweep is offset against each other and for
chorus then either 1, 2 or all 3 taps are remixed with the original signal at
a configurable mix level. Changed the scan betweeen taps to be a more gentle
sloped fade rather than a linear transition. The scan delay and LC are user
configurable parameters and the tap scan time also to alter the overall speed
of rotation. Altered the addition and subtraction of taps to fatten out and
smoothen the sound. Reduced the spread of the taps since they are only
interesting at low delays. Filled out the lower scan ranges so that they at
least always scan between taps. It no longer sounds like it has a broken cap.

Added a build option to configure: --disable-jack-midi. There were complaints of
interoperability with the older jack MIDI libraries. I do not want to support
the previous releases and this is the lowest common denominator to allow the
application to at least build with the 0.103.0 API. The complaint is
"too few arguments to function 'jack_midi_get_event_count()'" or similar.

The audiodev name is now used for jack registrations. It is defaulted to the
program name when jack drivers are requested and then overwritten if given as
an explicit option. This allows visibility of each invocation of bristol into
jackd.

MS-20 was packing too many panels. Cleaned it up and added in the new ModWheel
however it still does not work - should move it along a little bit.

Minor bitmap manipulations for some resizing misfits using the -scale option.

Added some more output text for cases where jackd could not be started however
a review should be made of the the audio and midi thread status selections to
make the operation smoother.

Fixed some issues with detuning (sensitivity) where if not initialised it led
to unexpected results.

Put in limits testing in bristolMidiSendMsg(), something I did not want to do
preferring a well behaved GUI however it has lead to issues during development
that would have been nicer to have avoided and its at very little cost.

The per user private memory cache should now be enforced, this should allow
people to keep their private memories over reinstalls and upgrades. Prior to
this the cache was only used if the directory structure was in place however
that is rather unwieldly for most users for the current number of emulations.


    0.20.6 13 Jun 2008 Band limited oscllators. UI Heartbeats, GUI scaling.

Added in band limited master waveform tables for the base waves: square,
tri, ramp/saw, and a sine wave just to be complete. These were then pushed into
the diverse oscillator code for most of the emulations. The results are a lot
smoother if a sufficient number of harmonics is used, '-blo 21' or more, however
smaller values also give interesting results. The Mini is generally improved by
not having the 'infinate bandwidth' geometrically correct waveforms, the sound
is softer and warmer with relatively few harmonics. The next work on the sound
generation will need to go into the filter.

GUI now sends active sensing updates to the engine. This means the engine can
detect UI failure and exit rather than hang around and damage the next attempt
to connect (with the same MIDI channels, etc). There is one timer to control
the rate at which the GUI sends updates and another time for when the engine
will decide to stop the emulation. The GUI can detect failure of the engine
the same way - the write operation of the active sense will fail if the TCP
connection terminates at the remote side. The code could be improved, it
should actually scan the list of synths however it is pretty trivial to extend
it later. The reason is that the heartbeats are per emulation rather than at
the top level however the generation of the heartbeats occurs in the GUI in a
separate MIDI thread and hence is at the top level.

GUI now has a -scale option to presize the window. Default remains 1.0 and at
large scaling will automatically enable aliastype 'pre'. This can be overridden
with -aliastype none. There were too many remarks about the diminutive size
of the GUI and whilst the author likes the size this option improves usability.

Started work on a Yamaha CS-80.

Backing of Realistic MG-1 was offset since the prealiasing code, needed to be
corrected (actually had a third layer still packed but not used).

Explorer glide was not working due to changes to the operator indeces in the
emulation not being mirrored in the GUI.

Change the max device ccont from 128 to 512, already under the limit with some
of the synths probably leading to a few of the crashes I have been seeing.

Applied build patches from Alexis Bailler's gentoo packaging.

With antialias and mobile devices (sliders) we need to repaint extra pixels
during move operation or the 'blur' starts to stain the image. Fixed with some
minor alterations to the Undraw code extending its range by a pixel on the X
and Y axis.

XImage creation failure now suggests using the '-pixmap' option but its almost
a case of better never than late. I could consider changing the flag and then
attempting the load again however this may already be a non-issue (was a broken
64 bit X Server issue).

Introduced a lever operator that changes its size at it moves up and down its
scale. This was for a part of the CS80 code.

Added a configurable timer into the GUI host code midi scanning period.

Horizontal scales needed redrawing fixes.

    0.20.5 20 Apr 2008 First release of the Jupiter-8 emulation, GUI prealiasing, Vasiliy Basic's Mini memory suite.

Integrated a 4+4 split/layerable Jupiter algorithm with arpeggiator, sequencer
and chording function assignable per layer. Full write up in the README file.

Changed the Jupiter design such that the VCO have selector buttons rather than
single switches for register and waveform. This is not per the original but it
allows me to make them non-exclusive and that will fatten up the sound. This
functionality is more like the JP-6 and MKS-80.

This code includes a Jack MIDI client interface. It is started with the normal
options plus '-midi jack' so that it can be used in parallel to an ALSA link
and TCP link to the GUI. The result is that the engine uses two midi threads,
one doing bulk operations for GUI settings which might be quite slow, a higher
priority thread doing Jack MIDI, and the highest priority thread doing the
audio processing. Semaphores are implemented to prevent the threads interfering
with eachother.

Reorganised qwerty mappings for correct MIDI note selection and transpositions,
brightonController.c confdev may need to be buried in window structures.
Worked especially for a couple of keyboards that were not C-C.

Implemented a prealiasing code which uses whole pixel blending. It is only
applied to the silkscreens and gives far better imaging when the synths are
resized towards fullscreen - they are still reasonably readable. Reducing the
window size and normal size are a bit blurred. Configured with '-aliastype pre'.

Reevaluated the arpeggiator step rates to go from 1Hz to 20Hz.

The implementation of antialiasing allow threw light on some coredumps at
very small window sizes caused by anomalies in the drop shadow rendering
going negative due to the small sizes.

Arpeggiator did not correctly terminate the note list when more keys than
available voices were pressed. Resulted in hanging arpeggiation and holes in
the arpeggiation sequence.

Resizing windows failed on some emulations with the output signal going to
zero: If some of the GUI settings did not match the engine before the resize
then the sound will change. We should suppress all updates when resizing since
no changes should happen to the engine.

Resolved an issue with the -emulate and its interpretation of gain levels,
they were a bit low.

Touched up the rhodes bass graphics. Minimal, but was bored.

Minor touch ups to the memorymoog, prophet, prophet52, axxe, odyssey, mini,
explorer and rhodes shading graphics. Adjusted some offsets on the B3 to
prevent some lines of transparency on resizing.

    0.20.4 26 Mar 2008 Arpeggiating OB-Xa, fixes, synchronised threads.

This is maintenance code however you may prefer to defer using it until 0.20.5
is released. There are numerous fixed integrated here however the midi note
event management has changed considerably and there may be some anomalies in the
implementation of the multiple dual linked listed that govern key assignments.
The symptoms of such anomalies are potentially quite ugly if you run bristol
with real time scheduling, the tight loops may lock your system so you may
want to run it with '-priority 0' for no realtime prioritisation. There may be
lots of thread and arpeggiator diagnostics that will also disappear in the next
release but you can also use the -quiet flag to prevent them.
Also, since the MIDI and audio thread now use exclusion then a very busy audio
thread may result in what appear to be dropped notes: The note_on gets delayed
due to system overhead but eventually generates a 'newlist' entry for the
engine to process. If the note_off arrives before the audio thread has taken
the newlist entry then it is removed before it even gets started. These actions
are visible with the current debugging. A master keyboard should not be badly
affected by this however the GUI can end up clumping together multiple events
if the CPU load is high and that causes/exacerbates the situation.

Reworked the OBXa for some stronger sounds with a couple of routing corrections.
Overall sounds is a lot richer. This lead to changing the glide to be a log
controller rather than lin, another improvement that will affect existing
memories though. Will become a general capability. Fixed some flagging issues
with OBX modpanel and layer assignments. Adjusted the mod mix and corrected
the mod LFO rate controller. Should build some more OBXa memories as well.
Rework OBXa dual/split options for single midi channel. Reworked some of the
OBXa graphics including a shading layer ready for distribution.

Arpeggiating sequencing now records under suitable control - only emulation with
an interface is in the OBXa, Bit-100 but others may follow. The settings can be
saved in a memory to be recalled and recoded to the engine. There is serious
fun to be had now with the OBX-a emulator and sequencing/arpeggiation. Details
are in the readme file but basically start arpeggiating and then crank down
the filter envelope decay and play with the filter cutoff and mod level.

Implemented the chording code as a small extension to the 0.20.3 sequencer.
When enabled it will assign a voice to every note in the note list, transposing
them as it goes.

Worked the arpeggiator changes back into the Juno-60 code. Made the OBX-a Seq
be once per voice rather than once per synth.

The LFO rate parameter was converted to a log controller rather than a linear
one, it improves response and allows for some very slow cycles. It will affect
some memory settings. Glide also changed to logarithmic control. Arpeggiator
rate similarly.

The memory library was changed such that it honoured the active parameter
when calling memory locations, something that may well have changed the
characters of the other synths. Went through the code to clean up the obvious
ones but should run through them all again.

It is now possible to have the GUI search for an emulation rather than passing
the emulation exlicitly. This is with the -emulate option. The feature also
sets default voice counts, detunes, gains, etc, from the emulation such that
the options such as "-voices 10 -emulate jupiter8" and "-voices 10 -jupiter8"
are different - the first call would default the voice count to 8 from the
emulator, the second would have the emulate inherit the explicit option of 10
voices and since we have not actually requested an emulation then the remaining
options will not be taken from the application defaults.

Installed some new key bitmaps, not sure about the results as they look a little
surreal, almost chrome rather than ebony.

Corrected some tv_usec comparison failures that were damaging the double click
timers and defaulting to 1000ms only.

The bristol ASLA seq interface would misinterpret note on/velocity zero. Caused
some strange results with certain keyboards, and only with some bristol
features (arpeggio) since it is correctly reinterpretted later in the chain.
Also, the OB-Xa midi tracking would double strike with the GUI linked up to
the master controller, the GUI was not honouring exclusion and retransmitted
midi events already seen by the engine.

Reorganise the transposition system for some emulations, they now correctly
request the transpose to the engine rather than just scale their own keyboard.
Both methods work and are arguably both correct however unless the engine is
informed of a tranposition then it will not be audibile from a master keyboard
driving the engine. This alteration needs to be reviewed as it separates the
midi key id from the qwerty keyboard id's and that is awkward for anybody who
wants to build their own mapping files. The mapping is now not qwerty key to
midi key but qwerty key to GUI button index - for most emulations this is the
key 0 to 60 on a 61 notes keyboard. Also separated the mapping table per
window rather than globally - when the GUI goes medusa this will be required.

Resolved another window timing issue with note on events at high load. This
required using a couple of semaphores and was a big change to the note event
management. It ironed out a few other unlikely situation such as running two
monophonic synths simultaneously would give unexpected results - their note
selections could get intermixed. The use of semaphores for mutual exclusion
of the midi and audio threads was very worth the effort as it will probably
be used to distribute load over different cores with multiple audio threads
presently.

Resolved a lingering seg fault in the DX operator with the bounds checking
that was added and cleaned up the L1/L2 gain levels to be lin rather than log,
the log did not work well for these controls.

Fixed a heap corruption in GUI has needed addressing for rather a long time
instead of providing a long term workaround. Resolved a couple of related
issues with detection of pure blue from negative offsets that also caused
segfaults that have been annoying me for a while. The workaround that had
been in place for several releases was pretty ugly.

Cleaned up some parts of the code that were giving in my opinion spurious
error messaging during compilation.

    0.20.3 05 Mar 2008 Integrated a new Crumar Bit-100 emulation

Finalised the bit-100, some extra options, ability to save -1 and -99 memories.

Restructured the rate algorithm for the glide, there were historical issues
with its mathematical correctness. Additionally added a bristol NRP to allow
the maximum glide time to be configurable. The default value was up to 30s
however that often felt excessive and makes configuring short values awkward,
changed this to be 10s with the ability to request up to 30. The GUI now
responds to the -glide option per emulation and the Bit emulations have memory
parameterisation.

Added pink and filtered noise options to the BIT synths, defaults to white. The
option 'white' could be dropped and turned into Pink with progressive filter.

Added a flag required to enable NRP parameter changes in the engine. Default
is now not to pass them for interpretation since it is a rather arbitrary
interface and has been probably responsible for noisy interaction with some
master keyboards.

Diverse fixes to the BIT emulations:
Layer volumes were damaged going into split/layer settings.
Layer transpose, split and midi channel tracking needed some corrections for
the different options. Specifically there are flags for supporting different
settings per layer (per default they remain in sync) and these were not being
honoured.
The same fixes were required to ensure that non-aligned settings would be
correctly returned after dual loading splits and layers.
Layer parking was damaged (required writeThru cache enabled to work).
Memory loading was damages for high ordered parameters.
More issues with the high order parameters.

Restructured the arpeggiator to cetralise the code ready to put it into the
Jupiter emulator. Code inserted to allow the arpeggiator to hook into the
midi note event dispatching to prepare it for reprogramming.

Tested now with jack 0.99, 0.103 and 0.109 successfully.

Updated copyright dates to reflect 2008.

    0.20.2 25 Feb 2008 Integrated a few Crumar Bit emulations.

Edited brightonButton for highlighted buttons, required repainting the control
and could be rolled back into the brightonButton rather than being separate.
Build a Crumar Bit-99/Bit-1 and an m2, all variations on the bit-99. Added
several bristol features via data entry parameters. The capabilities and the
differences to the original are documented on the website and in the README
files with the distribution.
Patched in a dummy audio driver such that no audio operations are executed. This
may seem rather daft for a synth however working under virtualized systems often
gives dodgy and unreliable audio interfacing so having a dummy lets me still
work on the GUI to engine interfacing rather than limiting the work to the GUI.
This is accessible with '-audio dummy'.
Fixed an issue with port redirection and multilayer synths failing.
NRP were being incorrectly interpreted which meant that emulation gains and
detunes were not being registered.
Velocity of note off events was being mapped into voice velocity as well as
note-off velocity. This is incorrect as it causes jumps in envelope gains, etc.
The correct behaviour is for device that want to use note off velocity should
search for it in the correct place. The bristol ADSR does not adjust release
rates by velocity however it could by using this explicitly.
The envelope uses a power gain curve that is precalculated for lookups on
attack/decay rates. It was a little damaged at the zero point and could cause
'inf' failures on some of the work being done, highly inefficient. Only seen
in very rare cases and normally just during development since the code avoided
using the limits. Corrected.
Implemented OMNI mode however only the Crumar allow access to it at the moment.
Transpose has been reimplemented such that the MIDI library is correctly
handling the transpose. Previously it would lose track of some notes - press
key 36, transpose 12 notes and it would not be able to match the note off to the
original note on. The fix was resonable trivial and now the rest of the synths
should also start using this method, something that will happen later.
Velocity control has been added into the GUI so that it can be requested at
start time per emulation. I should try and document all the 500 or so different
mappings - the only references at the moment are the source code.

    0.20.1 20 Jan 2008 First release of the 0.20 stream

Designed a 7 segment red led digit display for the Jupiter panel. The original
had an 8 segment display however the floating point was superfluous and has
been left out.
Compilation without jack or ALSA would fail dismally, the make routines would
not pull out all the ALSA definitions. There may remain some issues since the
OSS Midi interface does not seem to work, only rawmidi. If you really want OSS
support with MIDI and all then mail the author. The changes altered the list of
drivers, removing the Sun D-BRI and ALSA revisions prior to 0.9, both of which
are now antiquated anyway.
The remaining audio interfaces are:

    OSS (pretty much any release as the interface is stable)
    ALSA 0.9 or greater (SND_LIB_MAJOR=1)
    Jack 0.99 or greater

There does not seem to be any jack version information available from the
include files at compile time unfortunately, something that may be an issue
with the currently new 0.109 release that appears to have altered the library
interface specification.

This should not be released until jackd with a 64 sample period size has been
tested (reported to fail) and we should also consider waiting until the jack
interface has been folded into the bristol audio library even though it does
not like being there. That may wait, the alterations the audio library to remove
the diverse unused interfaces and changes to the compilation flags seems to
improve stability (and may be ported back to 0.10 at some point). After that we
can start breaking things again.

Cleaned up some of the debuging.
Removed the bristol files from the brighton directory.
This release is based on 0.10.13 with the above changes.

    0.10.13 19 Jan 2008 Maintenance release.

Resolved a failure in the Vox M2 percussive harmonics, they were not decaying,
an issue with the operator selection in the GUI.
Cosmetic alterations to some of the vox switch images, prophet panels, etc.
Added some bounds checking to the jack interface to prevent a couple of errors
that occur when failing to open the interface.
XImage issues with 64bit sytems - the XCreateImage() fails due to pad and line
length errata. Workaround is to use -pixmap (avoids the XImage acceleration
code) and the fix needs testing but does not break 32 bit systems.
This will be the last development of 0.10 stream, no more features only bug
fixes. Further developments will go into the pending 0.20 stream.

    0.10.12 03 Dec 2007 Maintenance release.

RT priority is now defaulted to 75, a value of zero for the runtime parameter
does not reschedule the thread at all, it is left up to the linked libraries.
Vox Continental would segfault due to pedalboard buffer pointers.
Implemented a workaround for damaged segment sizes with some jack attachements
but this is not really a fix, it just avoids the problem by exiting a little
more gracefully when there is a mismatch. It may become the fix though, the
problem only happens when I cannot find the period size a priori.
Reworked parts of the engine code such that it checks for data availability
with select rather than going into a wait state. This is a lot cleaner as it
has a timeout for failure situations. Timer defaults to a few seconds only,
that could be improved.
Rhodes voices were broken due to reorganisation of the ADSR default gain to be
liniar rather than logarithmic, firstly the notes barely decayed but also the
harmonic content did not vary from the FM algorithm.
Integrated a chorus into the Rhodes GUI and a wrapper in the engine FM code.

    0.10.11 27 Oct 2007 Arpeggiator written into the MIDI library.

Reworked the Juno image for more edging and new sliders.
Built some default "temperature sensitivity" into the dual manual synths, it
should improve the sound, at least when layered.
Reorganised the voice initialisation code to have better GM2 conformancy.
Double click timout made into a GUI configurable option.
Added a 7 segment LED digit block to the library for the Jupiter display.
Implemented the arpeggiator for the Juno. It was a requirments for the Jupiter
however it is easier to test with a synth that already works.
Reworked the threeway switch so that it was sequential, required some changes
to the emulations using them.

    0.10.10 01 Oct 2007 Bass pedalboard integration for Hammond and VOX.

Fixed the Vox M2 memories. Also reworked the octave frequency of its harmonics
since the reed should be an octave higher. The bass pedals are now visible but
the envelope closes early under some situations.
The frequency table for the VOX was 'too correct', rewrote the vox microtonal
map to have a table based on integer division from 1MHz to introduce a few
cents of detune as per original.
Some of the microtonal maps were incorrect, loss of key 108. Had no effect as
none of the emulations used the microtonal map however it needed to be fixed.
Put a bass pedalboard into the Hammond B3 emulation. It requires extra graphics
space which is not an issue, and for both emulations the pedalboards kind of
come for free - they use the same MIDI channel as the lower manual but call a
different oscillator depending on MIDI note. The B3 memory structures had to
change to support the lower manual drawbars. If you had your own memories
in ~/.bristol/memory/hammondB3/* then you should really delete them.
Made the audio thread priority a runtime option.
Reworked the prophet pot bitmaps for higher contrast and closer alignment.
Distributing the GM2 MIDI controller mappings as default, not all emulations
support it though - does not work well for the dual manual synths nor the
organs.

    0.10.9 16 Sept 2007 Reworked installation procedures, Vox-300

Thanks to Nicolai Lissner for some directions on the autoconf install locations.
Made some fixes to the control key interpretation however, correctly speaking,
it is still actually damaged. The 'incorrectness' is minimal so will spare any
resolution until it really is needed.
Finished work on a dual manual VOX Super Continental (M-II, 300, etc), most of
it works, the only unimplemented feature is the bass sustain envelope.
Recoloured the Memory Moog buttons.

    0.10.8 01 Sept 2007 Realistic Concertmate, recolorations, fixes

Fixed some issues with the OB routing for correcting the mix button settings.
Transparency shadow would damage on redrawing. Fixed for the hammond however
for some of the synths (pro10) this shadow is lost on resizing the window. FFS.
Minor recolouration of some of the hammond bitmaps for offwhite controls.
Recoloration of the ARP Odyssey sliders.
ARP Odyssey Ring Mod was broken due to 2600 alterations.
Was bored, so programmed a Realistic (Moog) Concertmate MG-1 as a giveaway.

    0.10.7 29 Jul 2007 migration of graphics from pixmap to ximage

Net performance improvement just for this one change is 5 to 10 times the
rendering rate. The brighton and B11 library are now again in the same
order of magnitude of CPU requirements with brighton about 1/4 of the B11
interface. The overall improvement is best reviewed with the ARP 2600, before
all the optimisations it could take over 10 seconds to load a memory, now it
is probably closer to 1/10th of a second. There are still some issues with
the XImage interface and this is a configurable option (--disable-ximage)
however I am also going to turn this into a runtime option rather than just
compile time.

Now that the interface speed is optimised the antialiasing code has been
reintroduced again as a compile and runtime option. It does have a performance
hit. The antialiasing has two parameters, the depth of bit masking and the
type - texture or all. Antialiasing with the 'all' option affects the total
representation, using the texture option only affects the backgrounds such
that the devices maintain clarity.

Added a monochrome '-grayscale' option, aliasaed as '-gs|-greyscale' which
does late stage color replacement to shades of gray. In itself it is not very
useful as all displays are color however the algorithms for color conversion
will be used presently in some menuing features. There are 5 values:

    1 is an average of the three color components.
    2 is half the average (dimming)
    3 is quarter the average (dimming)
    4 is the minimum component
    5 is the maximum component

Of these the first 3 will be used, in a generalised algorithm, for the grey
shaded floating menus.

    0.10.6 27 June 2007 bugfixes and GUI efficiency improvements.

Implemented a color cache to optimize the rendering algorithm. It changes the
'quality' parameter to a BBP value to which colors are rounded (thus affecting
the quality of the rendered image) and uses the subsequent red color as an
index into a cache table. Each row is a doubly linked sorted list, first by
green, then blue by green. Search depth is now no longer the average of half
the number of colors but closer to half the row length (which in turn depends
on the color quality). Delivers about 10 to 50 times improvement, especially
for the color intensive transparency layers. Cache stats are available from
the ^P XPM dump command. The remaining inefficiencies in the brighton X11 lib
should now also be addressed. Prior to these changes the brigton interface
itself was the most intensive operation, it is now only about 10% of the CPU
required to repaint, hence there is space for another 5 to 10 fold improvement.

Corrected inefficiencies in the horizontal scaler repainting. Originally this
painted the whole width of the scaler and was resolved to just paint the area
redrawn by the movement, roughly doubling its performance.

Perfectly vertical patchcables were incorrecty rendered. The actual painting
was correct however the rendering onto the screen was too narrow.

    0.10.5 06 June 2007 added roadrunner electric piano

    0.10.4 24 May 2007 added Solina string machine

Potentials:
Some of the diverse synth memories are damaged.
ARP 2600 has damaged vertical patch cables.
Move the key mappings and controller mappings to .mcm file as they are static.
Removed clipping in new keyclick generation.

    0.10.3 18 May 2007 added the following

Modifications to configure.ac and Makefile.am to correct autotools errors.
Corrected use of --exec_prefix for configure process.

Note velocity, Poly and Channel Pressure curve mappings from file. Global.
Note integer index mapping in same configuration file. Global.
Note Microtonal tunings. Global settings - affects the whole engine.

Note velocity map - per emulation.
Note microtonal map - per emulation.

B3 key noise generated per bus with configurable delays and gain per contact.
Reverse controller motion of hammond drawbars (mappings?).

Controller mapped value curves for lin/log/exp/parabolic with inverse table.

Resolved issues with use of '-jack' flag as opposed to '-audio jack'.

More keyboard velocity curves of which one mapping per emulation.

Pitch bend damaged by microtonal mapping implementation, fixed.

    0.10.2: 10 May 2007

Changes to automake configuration files for installation prefixes.

    0.10.1: 4 May 2007

Probable first distribution of the bristol version using GNU autotools.