Documentation / blockdev / paride.txt

Based on kernel version 4.16.1. Page generated on 2018-04-09 11:52 EST.

	
			Linux and parallel port IDE devices
	
	PARIDE v1.03   (c) 1997-8  Grant Guenther <grant@torque.net>
	
	1. Introduction
	
	Owing to the simplicity and near universality of the parallel port interface
	to personal computers, many external devices such as portable hard-disk,
	CD-ROM, LS-120 and tape drives use the parallel port to connect to their
	host computer.  While some devices (notably scanners) use ad-hoc methods
	to pass commands and data through the parallel port interface, most 
	external devices are actually identical to an internal model, but with
	a parallel-port adapter chip added in.  Some of the original parallel port
	adapters were little more than mechanisms for multiplexing a SCSI bus.
	(The Iomega PPA-3 adapter used in the ZIP drives is an example of this
	approach).  Most current designs, however, take a different approach.
	The adapter chip reproduces a small ISA or IDE bus in the external device
	and the communication protocol provides operations for reading and writing
	device registers, as well as data block transfer functions.  Sometimes,
	the device being addressed via the parallel cable is a standard SCSI
	controller like an NCR 5380.  The "ditto" family of external tape
	drives use the ISA replicator to interface a floppy disk controller,
	which is then connected to a floppy-tape mechanism.  The vast majority
	of external parallel port devices, however, are now based on standard
	IDE type devices, which require no intermediate controller.  If one
	were to open up a parallel port CD-ROM drive, for instance, one would
	find a standard ATAPI CD-ROM drive, a power supply, and a single adapter
	that interconnected a standard PC parallel port cable and a standard
	IDE cable.  It is usually possible to exchange the CD-ROM device with
	any other device using the IDE interface. 
	
	The document describes the support in Linux for parallel port IDE
	devices.  It does not cover parallel port SCSI devices, "ditto" tape
	drives or scanners.  Many different devices are supported by the 
	parallel port IDE subsystem, including:
	
		MicroSolutions backpack CD-ROM
		MicroSolutions backpack PD/CD
		MicroSolutions backpack hard-drives
		MicroSolutions backpack 8000t tape drive
		SyQuest EZ-135, EZ-230 & SparQ drives
		Avatar Shark
		Imation Superdisk LS-120
		Maxell Superdisk LS-120
		FreeCom Power CD 
		Hewlett-Packard 5GB and 8GB tape drives
		Hewlett-Packard 7100 and 7200 CD-RW drives
	
	as well as most of the clone and no-name products on the market.
	
	To support such a wide range of devices, PARIDE, the parallel port IDE
	subsystem, is actually structured in three parts.   There is a base
	paride module which provides a registry and some common methods for
	accessing the parallel ports.  The second component is a set of 
	high-level drivers for each of the different types of supported devices: 
	
		pd	IDE disk
		pcd	ATAPI CD-ROM
		pf	ATAPI disk
		pt	ATAPI tape
		pg	ATAPI generic
	
	(Currently, the pg driver is only used with CD-R drives).
	
	The high-level drivers function according to the relevant standards.
	The third component of PARIDE is a set of low-level protocol drivers
	for each of the parallel port IDE adapter chips.  Thanks to the interest
	and encouragement of Linux users from many parts of the world, 
	support is available for almost all known adapter protocols:
	
	        aten    ATEN EH-100                            (HK)
	        bpck    Microsolutions backpack                (US)
	        comm    DataStor (old-type) "commuter" adapter (TW)
	        dstr    DataStor EP-2000                       (TW)
	        epat    Shuttle EPAT                           (UK)
	        epia    Shuttle EPIA                           (UK)
		fit2    FIT TD-2000			       (US)
		fit3    FIT TD-3000			       (US)
		friq    Freecom IQ cable                       (DE)
	        frpw    Freecom Power                          (DE)
	        kbic    KingByte KBIC-951A and KBIC-971A       (TW)
		ktti    KT Technology PHd adapter              (SG)
	        on20    OnSpec 90c20                           (US)
	        on26    OnSpec 90c26                           (US)
	
	
	2. Using the PARIDE subsystem
	
	While configuring the Linux kernel, you may choose either to build
	the PARIDE drivers into your kernel, or to build them as modules.
	
	In either case, you will need to select "Parallel port IDE device support"
	as well as at least one of the high-level drivers and at least one
	of the parallel port communication protocols.  If you do not know
	what kind of parallel port adapter is used in your drive, you could
	begin by checking the file names and any text files on your DOS 
	installation floppy.  Alternatively, you can look at the markings on
	the adapter chip itself.  That's usually sufficient to identify the
	correct device.  
	
	You can actually select all the protocol modules, and allow the PARIDE
	subsystem to try them all for you.
	
	For the "brand-name" products listed above, here are the protocol
	and high-level drivers that you would use:
	
		Manufacturer		Model		Driver	Protocol
		
		MicroSolutions		CD-ROM		pcd	bpck
		MicroSolutions		PD drive	pf	bpck
		MicroSolutions		hard-drive	pd	bpck
		MicroSolutions          8000t tape      pt      bpck
		SyQuest			EZ, SparQ	pd	epat
		Imation			Superdisk	pf	epat
		Maxell                  Superdisk       pf      friq
		Avatar			Shark		pd	epat
		FreeCom			CD-ROM		pcd	frpw
		Hewlett-Packard		5GB Tape	pt	epat
		Hewlett-Packard		7200e (CD)	pcd	epat
		Hewlett-Packard		7200e (CD-R)	pg	epat
	
	2.1  Configuring built-in drivers
	
	We recommend that you get to know how the drivers work and how to
	configure them as loadable modules, before attempting to compile a
	kernel with the drivers built-in.
	
	If you built all of your PARIDE support directly into your kernel,
	and you have just a single parallel port IDE device, your kernel should
	locate it automatically for you.  If you have more than one device,
	you may need to give some command line options to your bootloader
	(eg: LILO), how to do that is beyond the scope of this document.
	
	The high-level drivers accept a number of command line parameters, all
	of which are documented in the source files in linux/drivers/block/paride.
	By default, each driver will automatically try all parallel ports it
	can find, and all protocol types that have been installed, until it finds
	a parallel port IDE adapter.  Once it finds one, the probe stops.  So,
	if you have more than one device, you will need to tell the drivers
	how to identify them.  This requires specifying the port address, the
	protocol identification number and, for some devices, the drive's
	chain ID.  While your system is booting, a number of messages are
	displayed on the console.  Like all such messages, they can be
	reviewed with the 'dmesg' command.  Among those messages will be
	some lines like:
	
		paride: bpck registered as protocol 0
		paride: epat registered as protocol 1
	
	The numbers will always be the same until you build a new kernel with
	different protocol selections.  You should note these numbers as you
	will need them to identify the devices.
	
	If you happen to be using a MicroSolutions backpack device, you will
	also need to know the unit ID number for each drive.  This is usually
	the last two digits of the drive's serial number (but read MicroSolutions'
	documentation about this).
	
	As an example, let's assume that you have a MicroSolutions PD/CD drive
	with unit ID number 36 connected to the parallel port at 0x378, a SyQuest 
	EZ-135 connected to the chained port on the PD/CD drive and also an 
	Imation Superdisk connected to port 0x278.  You could give the following 
	options on your boot command:
	
		pd.drive0=0x378,1 pf.drive0=0x278,1 pf.drive1=0x378,0,36
	
	In the last option, pf.drive1 configures device /dev/pf1, the 0x378
	is the parallel port base address, the 0 is the protocol registration
	number and 36 is the chain ID.
	
	Please note:  while PARIDE will work both with and without the 
	PARPORT parallel port sharing system that is included by the
	"Parallel port support" option, PARPORT must be included and enabled
	if you want to use chains of devices on the same parallel port.
	
	2.2  Loading and configuring PARIDE as modules
	
	It is much faster and simpler to get to understand the PARIDE drivers
	if you use them as loadable kernel modules.   
	
	Note 1:  using these drivers with the "kerneld" automatic module loading
	system is not recommended for beginners, and is not documented here.  
	
	Note 2:  if you build PARPORT support as a loadable module, PARIDE must
	also be built as loadable modules, and PARPORT must be loaded before the
	PARIDE modules.
	
	To use PARIDE, you must begin by 
	
		insmod paride
	
	this loads a base module which provides a registry for the protocols,
	among other tasks.
	
	Then, load as many of the protocol modules as you think you might need.
	As you load each module, it will register the protocols that it supports,
	and print a log message to your kernel log file and your console. For 
	example:
	
		# insmod epat
		paride: epat registered as protocol 0
		# insmod kbic
		paride: k951 registered as protocol 1
	        paride: k971 registered as protocol 2
	
	Finally, you can load high-level drivers for each kind of device that
	you have connected.  By default, each driver will autoprobe for a single 
	device, but you can support up to four similar devices by giving their
	individual co-ordinates when you load the driver.
	
	For example, if you had two no-name CD-ROM drives both using the
	KingByte KBIC-951A adapter, one on port 0x378 and the other on 0x3bc
	you could give the following command:
	
		# insmod pcd drive0=0x378,1 drive1=0x3bc,1
	
	For most adapters, giving a port address and protocol number is sufficient,
	but check the source files in linux/drivers/block/paride for more 
	information.  (Hopefully someone will write some man pages one day !).
	
	As another example, here's what happens when PARPORT is installed, and
	a SyQuest EZ-135 is attached to port 0x378:
	
		# insmod paride
		paride: version 1.0 installed
		# insmod epat
		paride: epat registered as protocol 0
		# insmod pd
		pd: pd version 1.0, major 45, cluster 64, nice 0
		pda: Sharing parport1 at 0x378
		pda: epat 1.0, Shuttle EPAT chip c3 at 0x378, mode 5 (EPP-32), delay 1
		pda: SyQuest EZ135A, 262144 blocks [128M], (512/16/32), removable media
		 pda: pda1
	
	Note that the last line is the output from the generic partition table
	scanner - in this case it reports that it has found a disk with one partition.
	
	2.3  Using a PARIDE device
	
	Once the drivers have been loaded, you can access PARIDE devices in the
	same way as their traditional counterparts.  You will probably need to
	create the device "special files".  Here is a simple script that you can
	cut to a file and execute:
	
	#!/bin/bash
	#
	# mkd -- a script to create the device special files for the PARIDE subsystem
	#
	function mkdev {
	  mknod $1 $2 $3 $4 ; chmod 0660 $1 ; chown root:disk $1
	}
	#
	function pd {
	  D=$( printf \\$( printf "x%03x" $[ $1 + 97 ] ) )
	  mkdev pd$D b 45 $[ $1 * 16 ]
	  for P in 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
	  do mkdev pd$D$P b 45 $[ $1 * 16 + $P ]
	  done
	}
	#
	cd /dev
	#
	for u in 0 1 2 3 ; do pd $u ; done
	for u in 0 1 2 3 ; do mkdev pcd$u b 46 $u ; done 
	for u in 0 1 2 3 ; do mkdev pf$u  b 47 $u ; done 
	for u in 0 1 2 3 ; do mkdev pt$u  c 96 $u ; done 
	for u in 0 1 2 3 ; do mkdev npt$u c 96 $[ $u + 128 ] ; done 
	for u in 0 1 2 3 ; do mkdev pg$u  c 97 $u ; done 
	#
	# end of mkd
	
	With the device files and drivers in place, you can access PARIDE devices
	like any other Linux device.   For example, to mount a CD-ROM in pcd0, use:
	
		mount /dev/pcd0 /cdrom
	
	If you have a fresh Avatar Shark cartridge, and the drive is pda, you
	might do something like:
	
		fdisk /dev/pda		-- make a new partition table with
					   partition 1 of type 83
	
		mke2fs /dev/pda1	-- to build the file system
	
		mkdir /shark		-- make a place to mount the disk
	
		mount /dev/pda1 /shark
	
	Devices like the Imation superdisk work in the same way, except that
	they do not have a partition table.  For example to make a 120MB
	floppy that you could share with a DOS system:
	
		mkdosfs /dev/pf0
		mount /dev/pf0 /mnt
	
	
	2.4  The pf driver
	
	The pf driver is intended for use with parallel port ATAPI disk
	devices.  The most common devices in this category are PD drives
	and LS-120 drives.  Traditionally, media for these devices are not
	partitioned.  Consequently, the pf driver does not support partitioned
	media.  This may be changed in a future version of the driver. 
	
	2.5  Using the pt driver
	
	The pt driver for parallel port ATAPI tape drives is a minimal driver.
	It does not yet support many of the standard tape ioctl operations. 
	For best performance, a block size of 32KB should be used.  You will
	probably want to set the parallel port delay to 0, if you can.
	
	2.6  Using the pg driver
	
	The pg driver can be used in conjunction with the cdrecord program
	to create CD-ROMs.  Please get cdrecord version 1.6.1 or later
	from ftp://ftp.fokus.gmd.de/pub/unix/cdrecord/ .  To record CD-R media 
	your parallel port should ideally be set to EPP mode, and the "port delay" 
	should be set to 0.  With those settings it is possible to record at 2x 
	speed without any buffer underruns.  If you cannot get the driver to work
	in EPP mode, try to use "bidirectional" or "PS/2" mode and 1x speeds only.
	
	
	3. Troubleshooting
	
	3.1  Use EPP mode if you can
	
	The most common problems that people report with the PARIDE drivers
	concern the parallel port CMOS settings.  At this time, none of the
	PARIDE protocol modules support ECP mode, or any ECP combination modes.
	If you are able to do so, please set your parallel port into EPP mode
	using your CMOS setup procedure.
	
	3.2  Check the port delay
	
	Some parallel ports cannot reliably transfer data at full speed.  To
	offset the errors, the PARIDE protocol modules introduce a "port
	delay" between each access to the i/o ports.  Each protocol sets
	a default value for this delay.  In most cases, the user can override
	the default and set it to 0 - resulting in somewhat higher transfer
	rates.  In some rare cases (especially with older 486 systems) the
	default delays are not long enough.  if you experience corrupt data
	transfers, or unexpected failures, you may wish to increase the
	port delay.   The delay can be programmed using the "driveN" parameters
	to each of the high-level drivers.  Please see the notes above, or
	read the comments at the beginning of the driver source files in
	linux/drivers/block/paride.
	
	3.3  Some drives need a printer reset
	
	There appear to be a number of "noname" external drives on the market
	that do not always power up correctly.  We have noticed this with some
	drives based on OnSpec and older Freecom adapters.  In these rare cases,
	the adapter can often be reinitialised by issuing a "printer reset" on
	the parallel port.  As the reset operation is potentially disruptive in 
	multiple device environments, the PARIDE drivers will not do it 
	automatically.  You can however, force a printer reset by doing:
	
		insmod lp reset=1
		rmmod lp
	
	If you have one of these marginal cases, you should probably build
	your paride drivers as modules, and arrange to do the printer reset
	before loading the PARIDE drivers. 
	
	3.4  Use the verbose option and dmesg if you need help
	
	While a lot of testing has gone into these drivers to make them work
	as smoothly as possible, problems will arise.  If you do have problems,
	please check all the obvious things first:  does the drive work in
	DOS with the manufacturer's drivers ?  If that doesn't yield any useful
	clues, then please make sure that only one drive is hooked to your system,
	and that either (a) PARPORT is enabled or (b) no other device driver
	is using your parallel port (check in /proc/ioports).  Then, load the
	appropriate drivers (you can load several protocol modules if you want)
	as in:
	
		# insmod paride
		# insmod epat
		# insmod bpck
		# insmod kbic
		...
		# insmod pd verbose=1
	
	(using the correct driver for the type of device you have, of course).
	The verbose=1 parameter will cause the drivers to log a trace of their
	activity as they attempt to locate your drive.
	
	Use 'dmesg' to capture a log of all the PARIDE messages (any messages
	beginning with paride:, a protocol module's name or a driver's name) and
	include that with your bug report.  You can submit a bug report in one
	of two ways.  Either send it directly to the author of the PARIDE suite,
	by e-mail to grant@torque.net, or join the linux-parport mailing list
	and post your report there.
	
	3.5  For more information or help
	
	You can join the linux-parport mailing list by sending a mail message
	to 
			linux-parport-request@torque.net
	
	with the single word 
	
			subscribe
	
	in the body of the mail message (not in the subject line).   Please be
	sure that your mail program is correctly set up when you do this,  as
	the list manager is a robot that will subscribe you using the reply
	address in your mail headers.  REMOVE any anti-spam gimmicks you may
	have in your mail headers, when sending mail to the list server.
	
	You might also find some useful information on the linux-parport
	web pages (although they are not always up to date) at
	
		http://web.archive.org/web/*/http://www.torque.net/parport/
	

• [ blockdev ]
• 00-INDEX
• [ drbd ]
• floppy.txt
• nbd.txt
• paride.txt
• ramdisk.txt
• README.DAC960
• zram.txt
•  

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