patch-2.1.122 linux/drivers/scsi/README.ppa

• Lines: 131
• Date: Mon Sep 14 11:11:44 1998
• Orig file: v2.1.121/linux/drivers/scsi/README.ppa
• Orig date: Mon Apr 8 05:47:34 1996

diff -u --recursive --new-file v2.1.121/linux/drivers/scsi/README.ppa linux/drivers/scsi/README.ppa
@@ -1,119 +1,16 @@
-README.ppa (c) 1996   Grant R. Guenther,  grant@torque.net
+-------- Terse where to get ZIP Drive help info --------
 
+General Iomega ZIP drive page for Linux:
+http://www.torque.net/~campbell/
 
-         The IOMEGA PPA3 parallel port SCSI Host Bus Adapter
+Driver achive for old drivers:
+http://www.torque.net/~campbell/ppa/
 
-                     as embedded in the ZIP drive
+Linux Parport page (parallel port)
+http://www.torque.net/parport/
 
+Email list for Linux Parport
+linux-parport@torque.net
 
-This README documents the Linux support for the parallel port version of
-IOMEGA's ZIP100.  The ZIP100 is an inexpensive and popular, but relatively 
-low performance, removable medium disk device.  The drive is also available
-as a regular SCSI device, but the driver documented here is for the
-parallel port version.  IOMEGA implemented the parallel port version by
-integrating (or emulating ?) their PPA3 parallel to SCSI converter into
-the ZIP drive.
-
-I have implemented a low-level driver, ppa.c,  for this parallel port 
-host bus adapter, thereby supporting the parallel port ZIP drive as a 
-regular SCSI device under Linux.
-
-It is possible that this driver will also work with the original PPA3
-device (to access a CDrom, for instance). But, the PPA3 is hard to find 
-and costs as much as the ZIP drive itself, so no-one has actually tried
-this, to the best of my knowledge.
-
-The driver was developed without the benefit of any technical specifications 
-for the interface.  Instead, a modified version of DOSemu was used to 
-monitor the protocol used by the DOS driver, 'guest.exe', for this adapter.
-I have no idea how my programming model relates to IOMEGA's design.
-(One technical consequence of this method:  I have never observed a
-SCSI message byte in the protocol transactions between guest.exe and
-the ZIP drive, so I do not know how they are delivered.  My working 
-hypothesis is that we don't have to worry about them if we don't
-send linked commands to the drive.)
-
-I'd like to thank Byron Jeff (byron@cc.gatech.edu) for publishing his
-observation that the 'guest' driver loads under DOSemu.  His remark was
-the stimulus that began this project.
-
-The ppa driver can detect and adapt to 4- and 8-bit parallel ports, but 
-there is currently no support for EPP or ECP ports, as I have been unable 
-to make the DOS drivers work in these modes on my test rig.
-
-The driver may be built in to the kernel, or loaded as a module.  It
-may be configured on the command line in both cases, although the syntax
-is different.  It may also be configured by editing the source file.
-
-Built-in drivers accept parameters using this LILO/LOADLIN command line
-syntax (omitted parameters retain their default values):
-
-        ppa=base[,speed_high[,speed_low[,nybble]]]
-
-For example:    ppa=0x378,0,3
-
-If a driver is loaded as a module the parameters may be set on the
-insmod command line, but each one must be specified by name:
-
-For example:    insmod ppa.o ppa_base=0x378 ppa_nybble=1
-
-(Notice the ppa_ prefix on each of the parameters in the insmod form.)
-
-Here are the parameters and their functions:
-
-Variable        Default    Description
-
-ppa_base        0x378   The base address of PPA's parallel port.
-ppa_speed_high  1       Microsecond i/o delay used in data transfers
-ppa_speed_low   6       Microsecond delay used in other operations
-ppa_nybble      0       1 to force the driver to use 4-bit mode.
-
-A word about the timing parameters:  the ppa_speed_low parameter controls 
-the widths of a large number of pulses that are sent over the parallel bus, 
-the narrower the pulses, the faster things go, but the greater the risk of 
-distortion by noise damping circuits in the parallel ports.  The 
-ppa_speed_high parameter controls the same delays, but during the data 
-transfer phase only.   In this phase, there is a lot of handshaking going 
-on and the pulse shaping should not be so much of an issue, but if you 
-see data corruption, you can increase this parameter as well.
-
-You might also want to reduce the timing values to attempt to increase
-the transfer rates on your system.  Please be careful to watch for
-SCSI timeout errors in your log files.  If you are getting timeouts, you
-have set these parameters too low.  The default values appear to be
-safe on most machines.
-
-If you have both the lp and ppa drivers in your kernel, you must ensure
-that they access different parallel ports.  By default, the lp driver is
-initialised early in the booting process, and it claims all parallel
-ports that it can find.  You may control this behaviour with a LILO or
-LOADLIN command line argument of the form:
-
-        lp=base0[,irq0[,base1[,irq1[,base2[,irq2]]]]]
-
-For example:    lp=0x278,7
-
-If you use this method, only the ports named will be adopted by the lp
-driver.  You can disable them all with lp=0 .
-
-So, if you have a printer on 0x3bc and a ZIP drive on 0x278 you would
-give the following options on your boot command:
-
-        lp=0x3bc ppa=0x278
-
-In this case lp would use the polling driver, since an interrupt was not 
-specified.
-
-If you want to share the same parallel port between a ZIP drive and a
-printer, you should build both the lp and ppa drivers as modules and
-load and unload one or the other as required.  This is clumsy but we
-currently have no protocol for synchronising access to shared parallel
-ports.
-
-For information about using the ZIP drive, please read the generic
-instructions in the SCSI-HOWTO and the man pages for the normal disk
-management tools,  fdisk, mkfs, mount, umount, etc.  There is a mini-HOWTO
-circulating concerning the use of the normal SCSI version of the ZIP
-drive, most of its comments will apply to disks connected through the
-ppa driver as well.
-
+Email for problems with ZIP or ZIP Plus drivers
+campbell@torque.net