NB: Grant (grant@torque.net) has not been able to work on ppSCSI since the middle of '99 owing to other priorities. For a short while after that, I (twaugh@redhat.com) had been keeping the ppSCSI suite current with 2.2 and 2.3 kernels. However they are now no longer maintained. For the patches, see:


I would recommend addressing any correspondence concerning these drivers to the linux-parport mailing list, rather than directly to me.

The text of the original web site appears below.




The second BETA-test of the ppSCSI suite of drivers for parallel port SCSI adapters is now available. This release repairs some problems in the 0.90 release and introduces three more modules. The drivers must still be built as loadable modules. You can find this release at


This patch applies to 2.2.10, but should also apply to other recent kernels.

The modules included are:

  • ppscsi: the core library module for ppSCSI
  • t348: a protocol module for the APA-348 and T348
  • t358: a protocol module for the APA-358 and T358
  • epsa2: a protocol module for the (old) Shuttle EPSA-2
  • epst: a protocol module for the Shuttle EPST and APA-1350
  • onscsi: a protocol module for the OnSpec 90c26
  • sparcsi: a protocol module for the SparCSI and ParaSCSI
  • I have tested these modules with a variety of devices on 2.2.9 systems in both UP and SMP configurations. (There may still be some issues on SMP systems.) The devices have included tapes, CD-ROMs, disks, and scanners. In particular, the HP-5200C parallel port scanner and the Microtek ScanMaker v310 have been tested with the epst and onscsi modules, respectively, using the SANE tools.

    To try this stuff out, you'll need to get the patch and apply it to your 2.2.10 source tree, rerun 'make config' (or 'make oldconfig') and build the modules. ppSCSI will work with or without parport support. Once the modules are built, make sure you have scsi_mod loaded, and whichever high-level drivers you need. Load ppscsi and finally one of the protocol modules. Assuming you have an appropriate adapter connected to one of your parallel ports, and that your SCSI bus is powering the adapter, you should see the standard SCSI messages within a few seconds.

    I'm going to assume that you are familiar with the Linux SCSI system and have a rough idea of how to proceed past this point.

    If you just want to try out the HP scanner support, the steps would be something like:

            insmod scsi_mod
            insmod sg
            insmod parport
            insmod parport_pc
            insmod ppscsi
            insmod epst
            scanimage -d hp:/dev/sg0 --mode Color > hpscan

    NB: If you do this under X don't be surprised if your system freezes for the duration of the scan. That's the downside of parallel port devices.

    While these devices will all work in SPP mode, I _strongly_ advise you not to try to scan in anything other than EPP mode.

    The protocol modules accept several parameters. They are documented in the comments at the beginning of ppscsi.c. The most important one is the "verbose" option. Specifying verbose=N will allow various messages to be logged to your console and/or kernel log. verbose=1 will enable progress reporting as the driver probes for adapters. verbose=2 enables tracing of the SCSI commands, 3 enables basic debugging and 4 gives full debugging messages. Be warned, verbose=4 can produce enormous logs.

    The "verbose" level, and several other parameters, can be changed by writing to files in the /proc/scsi tree. For instance, if you have a single epst adapter, it can be controlled through /proc/scsi/epst/0.

    	echo verbose=2 > /proc/scsi/epst/0

    will enable basic debugging, for instance. The /proc/scsi files can also be read to display parameters and statistics. (The level of detail displayed depends on the verbose level.)

    I am still working on a driver for the Belkin F5B001 adapter.

    Finally, please remember that testing any device driver has the potential to do serious damage to your file system. Make sure you take the necessary precautions before trying out the new drivers. Don't use one of these drivers to access the SCSI disk with the only copy of your thesis !


     Problems ?


    If you have any troubles with these drivers, please send me, grant@torque.net, some mail. I expect to release a few more BETA tests of ppSCSI over the next few weeks.

    If you'd like to contact other users who may be trying these drivers, please join the linux-parport mailing list and post your request or comments there.


     Small print


    Last update: December 23, 2003

    Tim Waugh <tim@cyberelk.net>
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