1=================================== 2Linux and parallel port IDE devices 3=================================== 4 5PARIDE v1.03 (c) 1997-8 Grant Guenther <grant@torque.net> 6 71. Introduction 8=============== 9 10Owing to the simplicity and near universality of the parallel port interface 11to personal computers, many external devices such as portable hard-disk, 12CD-ROM, LS-120 and tape drives use the parallel port to connect to their 13host computer. While some devices (notably scanners) use ad-hoc methods 14to pass commands and data through the parallel port interface, most 15external devices are actually identical to an internal model, but with 16a parallel-port adapter chip added in. Some of the original parallel port 17adapters were little more than mechanisms for multiplexing a SCSI bus. 18(The Iomega PPA-3 adapter used in the ZIP drives is an example of this 19approach). Most current designs, however, take a different approach. 20The adapter chip reproduces a small ISA or IDE bus in the external device 21and the communication protocol provides operations for reading and writing 22device registers, as well as data block transfer functions. Sometimes, 23the device being addressed via the parallel cable is a standard SCSI 24controller like an NCR 5380. The "ditto" family of external tape 25drives use the ISA replicator to interface a floppy disk controller, 26which is then connected to a floppy-tape mechanism. The vast majority 27of external parallel port devices, however, are now based on standard 28IDE type devices, which require no intermediate controller. If one 29were to open up a parallel port CD-ROM drive, for instance, one would 30find a standard ATAPI CD-ROM drive, a power supply, and a single adapter 31that interconnected a standard PC parallel port cable and a standard 32IDE cable. It is usually possible to exchange the CD-ROM device with 33any other device using the IDE interface. 34 35The document describes the support in Linux for parallel port IDE 36devices. It does not cover parallel port SCSI devices, "ditto" tape 37drives or scanners. Many different devices are supported by the 38parallel port IDE subsystem, including: 39 40 - MicroSolutions backpack CD-ROM 41 - MicroSolutions backpack PD/CD 42 - MicroSolutions backpack hard-drives 43 - MicroSolutions backpack 8000t tape drive 44 - SyQuest EZ-135, EZ-230 & SparQ drives 45 - Avatar Shark 46 - Imation Superdisk LS-120 47 - Maxell Superdisk LS-120 48 - FreeCom Power CD 49 - Hewlett-Packard 5GB and 8GB tape drives 50 - Hewlett-Packard 7100 and 7200 CD-RW drives 51 52as well as most of the clone and no-name products on the market. 53 54To support such a wide range of devices, PARIDE, the parallel port IDE 55subsystem, is actually structured in three parts. There is a base 56paride module which provides a registry and some common methods for 57accessing the parallel ports. The second component is a set of 58high-level drivers for each of the different types of supported devices: 59 60 === ============= 61 pd IDE disk 62 pcd ATAPI CD-ROM 63 pf ATAPI disk 64 pt ATAPI tape 65 pg ATAPI generic 66 === ============= 67 68(Currently, the pg driver is only used with CD-R drives). 69 70The high-level drivers function according to the relevant standards. 71The third component of PARIDE is a set of low-level protocol drivers 72for each of the parallel port IDE adapter chips. Thanks to the interest 73and encouragement of Linux users from many parts of the world, 74support is available for almost all known adapter protocols: 75 76 ==== ====================================== ==== 77 aten ATEN EH-100 (HK) 78 bpck Microsolutions backpack (US) 79 comm DataStor (old-type) "commuter" adapter (TW) 80 dstr DataStor EP-2000 (TW) 81 epat Shuttle EPAT (UK) 82 epia Shuttle EPIA (UK) 83 fit2 FIT TD-2000 (US) 84 fit3 FIT TD-3000 (US) 85 friq Freecom IQ cable (DE) 86 frpw Freecom Power (DE) 87 kbic KingByte KBIC-951A and KBIC-971A (TW) 88 ktti KT Technology PHd adapter (SG) 89 on20 OnSpec 90c20 (US) 90 on26 OnSpec 90c26 (US) 91 ==== ====================================== ==== 92 93 942. Using the PARIDE subsystem 95============================= 96 97While configuring the Linux kernel, you may choose either to build 98the PARIDE drivers into your kernel, or to build them as modules. 99 100In either case, you will need to select "Parallel port IDE device support" 101as well as at least one of the high-level drivers and at least one 102of the parallel port communication protocols. If you do not know 103what kind of parallel port adapter is used in your drive, you could 104begin by checking the file names and any text files on your DOS 105installation floppy. Alternatively, you can look at the markings on 106the adapter chip itself. That's usually sufficient to identify the 107correct device. 108 109You can actually select all the protocol modules, and allow the PARIDE 110subsystem to try them all for you. 111 112For the "brand-name" products listed above, here are the protocol 113and high-level drivers that you would use: 114 115 ================ ============ ====== ======== 116 Manufacturer Model Driver Protocol 117 ================ ============ ====== ======== 118 MicroSolutions CD-ROM pcd bpck 119 MicroSolutions PD drive pf bpck 120 MicroSolutions hard-drive pd bpck 121 MicroSolutions 8000t tape pt bpck 122 SyQuest EZ, SparQ pd epat 123 Imation Superdisk pf epat 124 Maxell Superdisk pf friq 125 Avatar Shark pd epat 126 FreeCom CD-ROM pcd frpw 127 Hewlett-Packard 5GB Tape pt epat 128 Hewlett-Packard 7200e (CD) pcd epat 129 Hewlett-Packard 7200e (CD-R) pg epat 130 ================ ============ ====== ======== 131 1322.1 Configuring built-in drivers 133--------------------------------- 134 135We recommend that you get to know how the drivers work and how to 136configure them as loadable modules, before attempting to compile a 137kernel with the drivers built-in. 138 139If you built all of your PARIDE support directly into your kernel, 140and you have just a single parallel port IDE device, your kernel should 141locate it automatically for you. If you have more than one device, 142you may need to give some command line options to your bootloader 143(eg: LILO), how to do that is beyond the scope of this document. 144 145The high-level drivers accept a number of command line parameters, all 146of which are documented in the source files in linux/drivers/block/paride. 147By default, each driver will automatically try all parallel ports it 148can find, and all protocol types that have been installed, until it finds 149a parallel port IDE adapter. Once it finds one, the probe stops. So, 150if you have more than one device, you will need to tell the drivers 151how to identify them. This requires specifying the port address, the 152protocol identification number and, for some devices, the drive's 153chain ID. While your system is booting, a number of messages are 154displayed on the console. Like all such messages, they can be 155reviewed with the 'dmesg' command. Among those messages will be 156some lines like:: 157 158 paride: bpck registered as protocol 0 159 paride: epat registered as protocol 1 160 161The numbers will always be the same until you build a new kernel with 162different protocol selections. You should note these numbers as you 163will need them to identify the devices. 164 165If you happen to be using a MicroSolutions backpack device, you will 166also need to know the unit ID number for each drive. This is usually 167the last two digits of the drive's serial number (but read MicroSolutions' 168documentation about this). 169 170As an example, let's assume that you have a MicroSolutions PD/CD drive 171with unit ID number 36 connected to the parallel port at 0x378, a SyQuest 172EZ-135 connected to the chained port on the PD/CD drive and also an 173Imation Superdisk connected to port 0x278. You could give the following 174options on your boot command:: 175 176 pd.drive0=0x378,1 pf.drive0=0x278,1 pf.drive1=0x378,0,36 177 178In the last option, pf.drive1 configures device /dev/pf1, the 0x378 179is the parallel port base address, the 0 is the protocol registration 180number and 36 is the chain ID. 181 182Please note: while PARIDE will work both with and without the 183PARPORT parallel port sharing system that is included by the 184"Parallel port support" option, PARPORT must be included and enabled 185if you want to use chains of devices on the same parallel port. 186 1872.2 Loading and configuring PARIDE as modules 188---------------------------------------------- 189 190It is much faster and simpler to get to understand the PARIDE drivers 191if you use them as loadable kernel modules. 192 193Note 1: 194 using these drivers with the "kerneld" automatic module loading 195 system is not recommended for beginners, and is not documented here. 196 197Note 2: 198 if you build PARPORT support as a loadable module, PARIDE must 199 also be built as loadable modules, and PARPORT must be loaded before 200 the PARIDE modules. 201 202To use PARIDE, you must begin by:: 203 204 insmod paride 205 206this loads a base module which provides a registry for the protocols, 207among other tasks. 208 209Then, load as many of the protocol modules as you think you might need. 210As you load each module, it will register the protocols that it supports, 211and print a log message to your kernel log file and your console. For 212example:: 213 214 # insmod epat 215 paride: epat registered as protocol 0 216 # insmod kbic 217 paride: k951 registered as protocol 1 218 paride: k971 registered as protocol 2 219 220Finally, you can load high-level drivers for each kind of device that 221you have connected. By default, each driver will autoprobe for a single 222device, but you can support up to four similar devices by giving their 223individual coordinates when you load the driver. 224 225For example, if you had two no-name CD-ROM drives both using the 226KingByte KBIC-951A adapter, one on port 0x378 and the other on 0x3bc 227you could give the following command:: 228 229 # insmod pcd drive0=0x378,1 drive1=0x3bc,1 230 231For most adapters, giving a port address and protocol number is sufficient, 232but check the source files in linux/drivers/block/paride for more 233information. (Hopefully someone will write some man pages one day !). 234 235As another example, here's what happens when PARPORT is installed, and 236a SyQuest EZ-135 is attached to port 0x378:: 237 238 # insmod paride 239 paride: version 1.0 installed 240 # insmod epat 241 paride: epat registered as protocol 0 242 # insmod pd 243 pd: pd version 1.0, major 45, cluster 64, nice 0 244 pda: Sharing parport1 at 0x378 245 pda: epat 1.0, Shuttle EPAT chip c3 at 0x378, mode 5 (EPP-32), delay 1 246 pda: SyQuest EZ135A, 262144 blocks [128M], (512/16/32), removable media 247 pda: pda1 248 249Note that the last line is the output from the generic partition table 250scanner - in this case it reports that it has found a disk with one partition. 251 2522.3 Using a PARIDE device 253-------------------------- 254 255Once the drivers have been loaded, you can access PARIDE devices in the 256same way as their traditional counterparts. You will probably need to 257create the device "special files". Here is a simple script that you can 258cut to a file and execute:: 259 260 #!/bin/bash 261 # 262 # mkd -- a script to create the device special files for the PARIDE subsystem 263 # 264 function mkdev { 265 mknod $1 $2 $3 $4 ; chmod 0660 $1 ; chown root:disk $1 266 } 267 # 268 function pd { 269 D=$( printf \\$( printf "x%03x" $[ $1 + 97 ] ) ) 270 mkdev pd$D b 45 $[ $1 * 16 ] 271 for P in 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 272 do mkdev pd$D$P b 45 $[ $1 * 16 + $P ] 273 done 274 } 275 # 276 cd /dev 277 # 278 for u in 0 1 2 3 ; do pd $u ; done 279 for u in 0 1 2 3 ; do mkdev pcd$u b 46 $u ; done 280 for u in 0 1 2 3 ; do mkdev pf$u b 47 $u ; done 281 for u in 0 1 2 3 ; do mkdev pt$u c 96 $u ; done 282 for u in 0 1 2 3 ; do mkdev npt$u c 96 $[ $u + 128 ] ; done 283 for u in 0 1 2 3 ; do mkdev pg$u c 97 $u ; done 284 # 285 # end of mkd 286 287With the device files and drivers in place, you can access PARIDE devices 288like any other Linux device. For example, to mount a CD-ROM in pcd0, use:: 289 290 mount /dev/pcd0 /cdrom 291 292If you have a fresh Avatar Shark cartridge, and the drive is pda, you 293might do something like:: 294 295 fdisk /dev/pda -- make a new partition table with 296 partition 1 of type 83 297 298 mke2fs /dev/pda1 -- to build the file system 299 300 mkdir /shark -- make a place to mount the disk 301 302 mount /dev/pda1 /shark 303 304Devices like the Imation superdisk work in the same way, except that 305they do not have a partition table. For example to make a 120MB 306floppy that you could share with a DOS system:: 307 308 mkdosfs /dev/pf0 309 mount /dev/pf0 /mnt 310 311 3122.4 The pf driver 313------------------ 314 315The pf driver is intended for use with parallel port ATAPI disk 316devices. The most common devices in this category are PD drives 317and LS-120 drives. Traditionally, media for these devices are not 318partitioned. Consequently, the pf driver does not support partitioned 319media. This may be changed in a future version of the driver. 320 3212.5 Using the pt driver 322------------------------ 323 324The pt driver for parallel port ATAPI tape drives is a minimal driver. 325It does not yet support many of the standard tape ioctl operations. 326For best performance, a block size of 32KB should be used. You will 327probably want to set the parallel port delay to 0, if you can. 328 3292.6 Using the pg driver 330------------------------ 331 332The pg driver can be used in conjunction with the cdrecord program 333to create CD-ROMs. Please get cdrecord version 1.6.1 or later 334from ftp://ftp.fokus.gmd.de/pub/unix/cdrecord/ . To record CD-R media 335your parallel port should ideally be set to EPP mode, and the "port delay" 336should be set to 0. With those settings it is possible to record at 2x 337speed without any buffer underruns. If you cannot get the driver to work 338in EPP mode, try to use "bidirectional" or "PS/2" mode and 1x speeds only. 339 340 3413. Troubleshooting 342================== 343 3443.1 Use EPP mode if you can 345---------------------------- 346 347The most common problems that people report with the PARIDE drivers 348concern the parallel port CMOS settings. At this time, none of the 349PARIDE protocol modules support ECP mode, or any ECP combination modes. 350If you are able to do so, please set your parallel port into EPP mode 351using your CMOS setup procedure. 352 3533.2 Check the port delay 354------------------------- 355 356Some parallel ports cannot reliably transfer data at full speed. To 357offset the errors, the PARIDE protocol modules introduce a "port 358delay" between each access to the i/o ports. Each protocol sets 359a default value for this delay. In most cases, the user can override 360the default and set it to 0 - resulting in somewhat higher transfer 361rates. In some rare cases (especially with older 486 systems) the 362default delays are not long enough. if you experience corrupt data 363transfers, or unexpected failures, you may wish to increase the 364port delay. The delay can be programmed using the "driveN" parameters 365to each of the high-level drivers. Please see the notes above, or 366read the comments at the beginning of the driver source files in 367linux/drivers/block/paride. 368 3693.3 Some drives need a printer reset 370------------------------------------- 371 372There appear to be a number of "noname" external drives on the market 373that do not always power up correctly. We have noticed this with some 374drives based on OnSpec and older Freecom adapters. In these rare cases, 375the adapter can often be reinitialised by issuing a "printer reset" on 376the parallel port. As the reset operation is potentially disruptive in 377multiple device environments, the PARIDE drivers will not do it 378automatically. You can however, force a printer reset by doing:: 379 380 insmod lp reset=1 381 rmmod lp 382 383If you have one of these marginal cases, you should probably build 384your paride drivers as modules, and arrange to do the printer reset 385before loading the PARIDE drivers. 386 3873.4 Use the verbose option and dmesg if you need help 388------------------------------------------------------ 389 390While a lot of testing has gone into these drivers to make them work 391as smoothly as possible, problems will arise. If you do have problems, 392please check all the obvious things first: does the drive work in 393DOS with the manufacturer's drivers ? If that doesn't yield any useful 394clues, then please make sure that only one drive is hooked to your system, 395and that either (a) PARPORT is enabled or (b) no other device driver 396is using your parallel port (check in /proc/ioports). Then, load the 397appropriate drivers (you can load several protocol modules if you want) 398as in:: 399 400 # insmod paride 401 # insmod epat 402 # insmod bpck 403 # insmod kbic 404 ... 405 # insmod pd verbose=1 406 407(using the correct driver for the type of device you have, of course). 408The verbose=1 parameter will cause the drivers to log a trace of their 409activity as they attempt to locate your drive. 410 411Use 'dmesg' to capture a log of all the PARIDE messages (any messages 412beginning with paride:, a protocol module's name or a driver's name) and 413include that with your bug report. You can submit a bug report in one 414of two ways. Either send it directly to the author of the PARIDE suite, 415by e-mail to grant@torque.net, or join the linux-parport mailing list 416and post your report there. 417 4183.5 For more information or help 419--------------------------------- 420 421You can join the linux-parport mailing list by sending a mail message 422to: 423 424 linux-parport-request@torque.net 425 426with the single word:: 427 428 subscribe 429 430in the body of the mail message (not in the subject line). Please be 431sure that your mail program is correctly set up when you do this, as 432the list manager is a robot that will subscribe you using the reply 433address in your mail headers. REMOVE any anti-spam gimmicks you may 434have in your mail headers, when sending mail to the list server. 435 436You might also find some useful information on the linux-parport 437web pages (although they are not always up to date) at 438 439 http://web.archive.org/web/%2E/http://www.torque.net/parport/ 440