2        Linux and parallel port IDE devices
4PARIDE v1.03 (c) 1997-8 Grant Guenther <>
61. Introduction
8Owing to the simplicity and near universality of the parallel port interface
9to personal computers, many external devices such as portable hard-disk,
10CD-ROM, LS-120 and tape drives use the parallel port to connect to their
11host computer. While some devices (notably scanners) use ad-hoc methods
12to pass commands and data through the parallel port interface, most
13external devices are actually identical to an internal model, but with
14a parallel-port adapter chip added in. Some of the original parallel port
15adapters were little more than mechanisms for multiplexing a SCSI bus.
16(The Iomega PPA-3 adapter used in the ZIP drives is an example of this
17approach). Most current designs, however, take a different approach.
18The adapter chip reproduces a small ISA or IDE bus in the external device
19and the communication protocol provides operations for reading and writing
20device registers, as well as data block transfer functions. Sometimes,
21the device being addressed via the parallel cable is a standard SCSI
22controller like an NCR 5380. The "ditto" family of external tape
23drives use the ISA replicator to interface a floppy disk controller,
24which is then connected to a floppy-tape mechanism. The vast majority
25of external parallel port devices, however, are now based on standard
26IDE type devices, which require no intermediate controller. If one
27were to open up a parallel port CD-ROM drive, for instance, one would
28find a standard ATAPI CD-ROM drive, a power supply, and a single adapter
29that interconnected a standard PC parallel port cable and a standard
30IDE cable. It is usually possible to exchange the CD-ROM device with
31any other device using the IDE interface.
33The document describes the support in Linux for parallel port IDE
34devices. It does not cover parallel port SCSI devices, "ditto" tape
35drives or scanners. Many different devices are supported by the
36parallel port IDE subsystem, including:
38    MicroSolutions backpack CD-ROM
39    MicroSolutions backpack PD/CD
40    MicroSolutions backpack hard-drives
41    MicroSolutions backpack 8000t tape drive
42    SyQuest EZ-135, EZ-230 & SparQ drives
43    Avatar Shark
44    Imation Superdisk LS-120
45    Maxell Superdisk LS-120
46    FreeCom Power CD
47    Hewlett-Packard 5GB and 8GB tape drives
48    Hewlett-Packard 7100 and 7200 CD-RW drives
50as well as most of the clone and no-name products on the market.
52To support such a wide range of devices, PARIDE, the parallel port IDE
53subsystem, is actually structured in three parts. There is a base
54paride module which provides a registry and some common methods for
55accessing the parallel ports. The second component is a set of
56high-level drivers for each of the different types of supported devices:
58    pd IDE disk
59    pcd ATAPI CD-ROM
60    pf ATAPI disk
61    pt ATAPI tape
62    pg ATAPI generic
64(Currently, the pg driver is only used with CD-R drives).
66The high-level drivers function according to the relevant standards.
67The third component of PARIDE is a set of low-level protocol drivers
68for each of the parallel port IDE adapter chips. Thanks to the interest
69and encouragement of Linux users from many parts of the world,
70support is available for almost all known adapter protocols:
72        aten ATEN EH-100 (HK)
73        bpck Microsolutions backpack (US)
74        comm DataStor (old-type) "commuter" adapter (TW)
75        dstr DataStor EP-2000 (TW)
76        epat Shuttle EPAT (UK)
77        epia Shuttle EPIA (UK)
78    fit2 FIT TD-2000 (US)
79    fit3 FIT TD-3000 (US)
80    friq Freecom IQ cable (DE)
81        frpw Freecom Power (DE)
82        kbic KingByte KBIC-951A and KBIC-971A (TW)
83    ktti KT Technology PHd adapter (SG)
84        on20 OnSpec 90c20 (US)
85        on26 OnSpec 90c26 (US)
882. Using the PARIDE subsystem
90While configuring the Linux kernel, you may choose either to build
91the PARIDE drivers into your kernel, or to build them as modules.
93In either case, you will need to select "Parallel port IDE device support"
94as well as at least one of the high-level drivers and at least one
95of the parallel port communication protocols. If you do not know
96what kind of parallel port adapter is used in your drive, you could
97begin by checking the file names and any text files on your DOS
98installation floppy. Alternatively, you can look at the markings on
99the adapter chip itself. That's usually sufficient to identify the
100correct device.
102You can actually select all the protocol modules, and allow the PARIDE
103subsystem to try them all for you.
105For the "brand-name" products listed above, here are the protocol
106and high-level drivers that you would use:
108    Manufacturer Model Driver Protocol
110    MicroSolutions CD-ROM pcd bpck
111    MicroSolutions PD drive pf bpck
112    MicroSolutions hard-drive pd bpck
113    MicroSolutions 8000t tape pt bpck
114    SyQuest EZ, SparQ pd epat
115    Imation Superdisk pf epat
116    Maxell Superdisk pf friq
117    Avatar Shark pd epat
118    FreeCom CD-ROM pcd frpw
119    Hewlett-Packard 5GB Tape pt epat
120    Hewlett-Packard 7200e (CD) pcd epat
121    Hewlett-Packard 7200e (CD-R) pg epat
1232.1 Configuring built-in drivers
125We recommend that you get to know how the drivers work and how to
126configure them as loadable modules, before attempting to compile a
127kernel with the drivers built-in.
129If you built all of your PARIDE support directly into your kernel,
130and you have just a single parallel port IDE device, your kernel should
131locate it automatically for you. If you have more than one device,
132you may need to give some command line options to your bootloader
133(eg: LILO), how to do that is beyond the scope of this document.
135The high-level drivers accept a number of command line parameters, all
136of which are documented in the source files in linux/drivers/block/paride.
137By default, each driver will automatically try all parallel ports it
138can find, and all protocol types that have been installed, until it finds
139a parallel port IDE adapter. Once it finds one, the probe stops. So,
140if you have more than one device, you will need to tell the drivers
141how to identify them. This requires specifying the port address, the
142protocol identification number and, for some devices, the drive's
143chain ID. While your system is booting, a number of messages are
144displayed on the console. Like all such messages, they can be
145reviewed with the 'dmesg' command. Among those messages will be
146some lines like:
148    paride: bpck registered as protocol 0
149    paride: epat registered as protocol 1
151The numbers will always be the same until you build a new kernel with
152different protocol selections. You should note these numbers as you
153will need them to identify the devices.
155If you happen to be using a MicroSolutions backpack device, you will
156also need to know the unit ID number for each drive. This is usually
157the last two digits of the drive's serial number (but read MicroSolutions'
158documentation about this).
160As an example, let's assume that you have a MicroSolutions PD/CD drive
161with unit ID number 36 connected to the parallel port at 0x378, a SyQuest
162EZ-135 connected to the chained port on the PD/CD drive and also an
163Imation Superdisk connected to port 0x278. You could give the following
164options on your boot command:
166    pd.drive0=0x378,1 pf.drive0=0x278,1 pf.drive1=0x378,0,36
168In the last option, pf.drive1 configures device /dev/pf1, the 0x378
169is the parallel port base address, the 0 is the protocol registration
170number and 36 is the chain ID.
172Please note: while PARIDE will work both with and without the
173PARPORT parallel port sharing system that is included by the
174"Parallel port support" option, PARPORT must be included and enabled
175if you want to use chains of devices on the same parallel port.
1772.2 Loading and configuring PARIDE as modules
179It is much faster and simpler to get to understand the PARIDE drivers
180if you use them as loadable kernel modules.
182Note 1: using these drivers with the "kerneld" automatic module loading
183system is not recommended for beginners, and is not documented here.
185Note 2: if you build PARPORT support as a loadable module, PARIDE must
186also be built as loadable modules, and PARPORT must be loaded before the
187PARIDE modules.
189To use PARIDE, you must begin by
191    insmod paride
193this loads a base module which provides a registry for the protocols,
194among other tasks.
196Then, load as many of the protocol modules as you think you might need.
197As you load each module, it will register the protocols that it supports,
198and print a log message to your kernel log file and your console. For
201    # insmod epat
202    paride: epat registered as protocol 0
203    # insmod kbic
204    paride: k951 registered as protocol 1
205        paride: k971 registered as protocol 2
207Finally, you can load high-level drivers for each kind of device that
208you have connected. By default, each driver will autoprobe for a single
209device, but you can support up to four similar devices by giving their
210individual co-ordinates when you load the driver.
212For example, if you had two no-name CD-ROM drives both using the
213KingByte KBIC-951A adapter, one on port 0x378 and the other on 0x3bc
214you could give the following command:
216    # insmod pcd drive0=0x378,1 drive1=0x3bc,1
218For most adapters, giving a port address and protocol number is sufficient,
219but check the source files in linux/drivers/block/paride for more
220information. (Hopefully someone will write some man pages one day !).
222As another example, here's what happens when PARPORT is installed, and
223a SyQuest EZ-135 is attached to port 0x378:
225    # insmod paride
226    paride: version 1.0 installed
227    # insmod epat
228    paride: epat registered as protocol 0
229    # insmod pd
230    pd: pd version 1.0, major 45, cluster 64, nice 0
231    pda: Sharing parport1 at 0x378
232    pda: epat 1.0, Shuttle EPAT chip c3 at 0x378, mode 5 (EPP-32), delay 1
233    pda: SyQuest EZ135A, 262144 blocks [128M], (512/16/32), removable media
234     pda: pda1
236Note that the last line is the output from the generic partition table
237scanner - in this case it reports that it has found a disk with one partition.
2392.3 Using a PARIDE device
241Once the drivers have been loaded, you can access PARIDE devices in the
242same way as their traditional counterparts. You will probably need to
243create the device "special files". Here is a simple script that you can
244cut to a file and execute:
248# mkd -- a script to create the device special files for the PARIDE subsystem
250function mkdev {
251  mknod $1 $2 $3 $4 ; chmod 0660 $1 ; chown root:disk $1
254function pd {
255  D=$( printf \\$( printf "x%03x" $[ $1 + 97 ] ) )
256  mkdev pd$D b 45 $[ $1 * 16 ]
257  for P in 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
258  do mkdev pd$D$P b 45 $[ $1 * 16 + $P ]
259  done
262cd /dev
264for u in 0 1 2 3 ; do pd $u ; done
265for u in 0 1 2 3 ; do mkdev pcd$u b 46 $u ; done
266for u in 0 1 2 3 ; do mkdev pf$u b 47 $u ; done
267for u in 0 1 2 3 ; do mkdev pt$u c 96 $u ; done
268for u in 0 1 2 3 ; do mkdev npt$u c 96 $[ $u + 128 ] ; done
269for u in 0 1 2 3 ; do mkdev pg$u c 97 $u ; done
271# end of mkd
273With the device files and drivers in place, you can access PARIDE devices
274like any other Linux device. For example, to mount a CD-ROM in pcd0, use:
276    mount /dev/pcd0 /cdrom
278If you have a fresh Avatar Shark cartridge, and the drive is pda, you
279might do something like:
281    fdisk /dev/pda -- make a new partition table with
282                   partition 1 of type 83
284    mke2fs /dev/pda1 -- to build the file system
286    mkdir /shark -- make a place to mount the disk
288    mount /dev/pda1 /shark
290Devices like the Imation superdisk work in the same way, except that
291they do not have a partition table. For example to make a 120MB
292floppy that you could share with a DOS system:
294    mkdosfs /dev/pf0
295    mount /dev/pf0 /mnt
2982.4 The pf driver
300The pf driver is intended for use with parallel port ATAPI disk
301devices. The most common devices in this category are PD drives
302and LS-120 drives. Traditionally, media for these devices are not
303partitioned. Consequently, the pf driver does not support partitioned
304media. This may be changed in a future version of the driver.
3062.5 Using the pt driver
308The pt driver for parallel port ATAPI tape drives is a minimal driver.
309It does not yet support many of the standard tape ioctl operations.
310For best performance, a block size of 32KB should be used. You will
311probably want to set the parallel port delay to 0, if you can.
3132.6 Using the pg driver
315The pg driver can be used in conjunction with the cdrecord program
316to create CD-ROMs. Please get cdrecord version 1.6.1 or later
317from . To record CD-R media
318your parallel port should ideally be set to EPP mode, and the "port delay"
319should be set to 0. With those settings it is possible to record at 2x
320speed without any buffer underruns. If you cannot get the driver to work
321in EPP mode, try to use "bidirectional" or "PS/2" mode and 1x speeds only.
3243. Troubleshooting
3263.1 Use EPP mode if you can
328The most common problems that people report with the PARIDE drivers
329concern the parallel port CMOS settings. At this time, none of the
330PARIDE protocol modules support ECP mode, or any ECP combination modes.
331If you are able to do so, please set your parallel port into EPP mode
332using your CMOS setup procedure.
3343.2 Check the port delay
336Some parallel ports cannot reliably transfer data at full speed. To
337offset the errors, the PARIDE protocol modules introduce a "port
338delay" between each access to the i/o ports. Each protocol sets
339a default value for this delay. In most cases, the user can override
340the default and set it to 0 - resulting in somewhat higher transfer
341rates. In some rare cases (especially with older 486 systems) the
342default delays are not long enough. if you experience corrupt data
343transfers, or unexpected failures, you may wish to increase the
344port delay. The delay can be programmed using the "driveN" parameters
345to each of the high-level drivers. Please see the notes above, or
346read the comments at the beginning of the driver source files in
3493.3 Some drives need a printer reset
351There appear to be a number of "noname" external drives on the market
352that do not always power up correctly. We have noticed this with some
353drives based on OnSpec and older Freecom adapters. In these rare cases,
354the adapter can often be reinitialised by issuing a "printer reset" on
355the parallel port. As the reset operation is potentially disruptive in
356multiple device environments, the PARIDE drivers will not do it
357automatically. You can however, force a printer reset by doing:
359    insmod lp reset=1
360    rmmod lp
362If you have one of these marginal cases, you should probably build
363your paride drivers as modules, and arrange to do the printer reset
364before loading the PARIDE drivers.
3663.4 Use the verbose option and dmesg if you need help
368While a lot of testing has gone into these drivers to make them work
369as smoothly as possible, problems will arise. If you do have problems,
370please check all the obvious things first: does the drive work in
371DOS with the manufacturer's drivers ? If that doesn't yield any useful
372clues, then please make sure that only one drive is hooked to your system,
373and that either (a) PARPORT is enabled or (b) no other device driver
374is using your parallel port (check in /proc/ioports). Then, load the
375appropriate drivers (you can load several protocol modules if you want)
376as in:
378    # insmod paride
379    # insmod epat
380    # insmod bpck
381    # insmod kbic
382    ...
383    # insmod pd verbose=1
385(using the correct driver for the type of device you have, of course).
386The verbose=1 parameter will cause the drivers to log a trace of their
387activity as they attempt to locate your drive.
389Use 'dmesg' to capture a log of all the PARIDE messages (any messages
390beginning with paride:, a protocol module's name or a driver's name) and
391include that with your bug report. You can submit a bug report in one
392of two ways. Either send it directly to the author of the PARIDE suite,
393by e-mail to, or join the linux-parport mailing list
394and post your report there.
3963.5 For more information or help
398You can join the linux-parport mailing list by sending a mail message
402with the single word
404        subscribe
406in the body of the mail message (not in the subject line). Please be
407sure that your mail program is correctly set up when you do this, as
408the list manager is a robot that will subscribe you using the reply
409address in your mail headers. REMOVE any anti-spam gimmicks you may
410have in your mail headers, when sending mail to the list server.
412You might also find some useful information on the linux-parport
413web pages (although they are not always up to date) at

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