xref: /freebsd/usr.sbin/fdcontrol/fdcontrol.8 (revision 0957b409) 
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26.\" $FreeBSD$
27.\"
28.Dd April 7, 2017
29.Dt FDCONTROL 8
30.Os
31.Sh NAME
32.Nm fdcontrol
33.Nd display and modify floppy disk parameters
34.Sh SYNOPSIS
35.Nm
36.Op Fl F
37.Op Fl d Ar dbg
38.Op Fl f Ar fmt
39.Op Fl s Ar fmtstr
40.Op Fl v
41.Ar device
42.Sh DESCRIPTION
43The
44.Nm
45utility allows the modification of the run-time behavior of the
46.Xr fdc 4
47driver for the device specified by
48.Ar device .
49.Pp
50Commands are implemented to query the current device density settings
51as well as the underlying device hardware as registered with the
52driver, to manipulate debugging levels, and to adjust the device
53density settings.
54All the operations that manipulate the kernel
55settings are restricted to the superuser (by the device driver), while
56all inquiry requests only require read access to
57.Ar device .
58.Pp
59The
60.Ar device
61argument should always be given as a full path name, e.g.\&
62.Pa /dev/fd0 .
63.Ss Inquiry Commands
64Running the
65.Nm
66utility without any of the optional flags will report the drive type
67that is registered with the device driver.
68In the shortest form, a single string describing the drive type will
69be returned.
70Possible values are:
71.Dq Li 360K ,
72.Dq Li 1.2M ,
73.Dq Li 720K ,
74.Dq Li 1.44M ,
75.Dq Li 2.88M ,
76or
77.Dq Li unknown .
78This information is primarily intended to be easily parsable by
79scripts.
80.Pp
81In order to add some descriptive text that makes the output better
82human readable, the flag
83.Fl v
84can be added.
85.Pp
86Specifying flag
87.Fl F
88will report the device's density settings in a form that is suitable
89as input to the
90.Fl s Ar fmtstr
91option (see below).
92Again, together with
93.Fl v ,
94some more text will be returned, including the total capacity of the
95density settings in kilobytes.
96.Ss Debug Control
97The
98.Xr fdc 4
99control utilities support two different options how to specify device
100density settings.
101The first form uses
102.Fl f Ar fmt
103to specify the format of the medium in kilobytes.
104Depending on the
105underlying drive type, the value is compared against a table of known
106commonly used device density settings for that drive, and if a match
107is found, those settings will be used.
108Currently, the following
109values for the respective drive types are acceptable:
110.Bl -item
111.It
1122.88M and 1.44M drives:
113.Bd -ragged -offset indent -compact
114.TS
115lB lB lB lB lB lB lB
116r l l l l l l.
117KB	sectrac	secsize	ncyls	speed	heads	flags
1181721	21	2 (512)	82	500	2	MFM
1191476	18	2 (512)	82	500	2	MFM
1201440	18	2 (512)	80	500	2	MFM
1211200	15	2 (512)	80	500	2	MFM
122820	10	2 (512)	82	250	2	MFM
123800	10	2 (512)	80	250	2	MFM
124720	9	2 (512)	80	250	2	MFM
125.TE
126.Ed
127.It
1281.2M drives:
129.Bd -ragged -offset indent -compact
130.TS
131lB lB lB lB lB lB lB
132r l l l l l l.
133KB	sectrac	secsize	ncyls	speed	heads	flags
1341200	15	2 (512)	80	500	2	MFM
1351232	8	3 (1024)	77	500	2	MFM
1361476	18	2 (512)	82	500	2	MFM
1371440	18	2 (512)	80	500	2	MFM
1381200	15	2 (512)	80	500	2	MFM
139820	10	2 (512)	82	300	2	MFM
140800	10	2 (512)	80	300	2	MFM
141720	9	2 (512)	80	300	2	MFM
142360	9	2 (512)	40	300	2	MFM,2STEP
143640	8	2 (512)	80	300	2	MFM
144.TE
145.Ed
146.It
147720K drives:
148.Bd -ragged -offset indent -compact
149.TS
150lB lB lB lB lB lB lB
151r l l l l l l.
152KB	sectrac	secsize	ncyls	speed	heads	flags
153720	9	2 (512)	80	250	2	MFM
154.TE
155.Ed
156.It
157360K drives:
158.Bd -ragged -offset indent -compact
159.TS
160lB lB lB lB lB lB lB
161r l l l l l l.
162KB	sectrac	secsize	ncyls	speed	heads	flags
163360	9	2 (512)	40	250	2	MFM
164.TE
165.Ed
166.El
167.Pp
168The second form to specify a device density uses
169.Fl s Ar fmtstr
170to explicitly specify each parameter in detail.
171The argument
172.Ar fmtstr
173is a comma-separated list of values of the form:
174.Pp
175.Sm off
176.Ar sectrac , secsize , datalen , gap , ncyls , speed ,
177.Ar heads , f_gap , f_inter , offs2 , flags
178.Sm on
179.Pp
180The meaning of the parameters is:
181.Bl -tag -width ".Ar secsize"
182.It Ar sectrac
183The number of sectors per track.
184.It Ar secsize
185The sector size code, 0 = 128 bytes (or less), 1 = 256 bytes, 2 = 512
186bytes, 3 = 1024 bytes.
187.It Ar datalen
188The actual sector size if the size code is 0, or the (ignored) value
1890xFF for larger size codes.
190.It Ar gap
191The length of the gap 3 parameter for read/write operations.
192.It Ar ncyls
193The number of cylinders.
194.It Ar speed
195The transfer speed in kilobytes per second.
196Can be 250, 300, 500, or
1971000, but each drive type only supports a subset of these values.
198.It Ar heads
199The number of heads.
200.It Ar f_gap
201The length of the gap 3 when formatting media.
202.It Ar f_inter
203The sector interleave to be applied when formatting.
2040 means no
205interleave, 1 means 1:1 etc.
206.It Ar offs2
207The offset of the sector numbers on side 2 (i.e., head number 1).
208Normally, sector numbering on both sides starts with 1.
209.It Ar flags
210A list from one of the following flag values:
211.Pp
212.Bl -tag -width ".Cm +perpend" -compact
213.It Cm +mfm
214Use MFM encoding.
215.It Cm -mfm
216Use FM (single-density) encoding.
217.It Cm +2step
218Use 2 steps per each cylinder (for accessing 40-cylinder media in
21980-cylinder drives).
220.It Cm -2step
221Do not use 2 steps per cylinder, i.e., access each physical cylinder
222of the drive.
223.It Cm +perpend
224Use perpendicular recording (for 2.88 MB media, currently not
225supported).
226.It Cm -perpend
227Use longitudinal recording.
228.El
229.El
230.Pp
231For any missing parameter, the current value will be used, so only
232actual changes need to be specified.
233Thus to turn off a flag bit
234(like
235.Cm +mfm
236which is the default for all drive types), the form with a leading
237minus sign must explicitly be used.
238.Sh EXAMPLES
239A simple inquiry about the drive type:
240.Bd -literal -offset indent
241$ fdcontrol /dev/fd0
2421.44M
243.Ed
244.Pp
245Same as above, but with verbose output.
246Note that the result is about
247the
248.Em "drive type" ,
249as opposed to a
250.Em "device density" ,
251so it is independent from the actual subdevice being used for
252.Ar device .
253.Bd -literal -offset indent
254$ fdcontrol -v /dev/fd0
255/dev/fd0: 1.44M drive (3.5" high-density)
256.Ed
257.Pp
258Inquiry about the density settings:
259.Bd -literal -offset indent
260$ fdcontrol -F /dev/fd0
26118,512,0xff,0x1b,80,500,2,0x6c,1,0,+mfm
262.Ed
263.Pp
264The verbose flag makes this human readable:
265.Bd -literal -offset indent
266/dev/fd0: 1440 KB media type
267        Format:         18,512,0xff,0x1b,80,500,2,0x6c,1,0,+mfm
268        Sector size:    512
269        Sectors/track:  18
270        Heads/cylinder: 2
271        Cylinders/disk: 80
272        Transfer rate:  500 kbps
273        Sector gap:     27
274        Format gap:     108
275        Interleave:     1
276        Side offset:    0
277        Flags           <MFM>
278.Ed
279.Pp
280As indicated, trailing commas in the parameter list may be omitted.
281.Pp
282In order to access archaic 160 KB single-density (FM encoded) 5.25
283media in a modern 1.2M drive, something like the following definition
284would be needed.
285(Note that not all controller hardware is actually
286capable of handling FM encoding at all.)
287.Bd -literal
288# fdcontrol -s 16,128,0x80,0x2,40,300,,0x10,,,-mfm,+2step /dev/fd1.1
289.Ed
290.Pp
291It is still possible to hook up 8" drives to most modern floppy
292controllers, given the right cable magic.
293(On PC hardware, tell the BIOS that it is a 5.25" drive.)
294The classical 128/26/2/77 format can be read with this entry
295.Bd -literal -offset indent
296fdcontrol -s  26,128,0x80,0x2,77,500,2,0x10,,,-mfm /dev/fd0
297.Ed
298.Sh SEE ALSO
299.Xr fdc 4
300.Sh HISTORY
301The
302.Nm
303utility appeared in
304.Fx 2.0 ,
305and was vastly overhauled in
306.Fx 5.0 .
307.Sh AUTHORS
308The program and this man page was contributed by
309.An J\(:org Wunsch ,
310Dresden.
311