8. Paralel port scanners

8.1. Where can I find more information on paralel port scanners?

Try the backend for your specific scanner.

Some scanners do SCSI over the parallel port. See http://www.torque.net/parport/ppscsi.html and http://www.buzzard.me.uk/jonathan/scanners.html

8.2. My scanner does SCSI over the parallel port. How do i set this up?

First a hardware note: the cable that comes with your scanner (or should come with your scanner) is not just a printer-cable.

Look at http://cyberelk.net/tim/parport/ppscsi.html for the software and the status. The rest of this answer used to be correct for the 2.4 kernel.

It has the latest bugfixes, and it should apply to just about any kernel. There is a version of the patch available at: ftp://people.redhat.com/twaugh/patches/linux24/linux-ppscsi.patch while there is also a cvs patch by Tim Waugh against the latest 2.4 kernel and happens to include the ppscsi modules, which you can find at: http://people.redhat.com/twaugh/ftp/patches/patch-cvs-tmw.gz A patch like these needs to be applied to the kernelsource in /usr/src/linux.

You can copy it there and do:

patch -p1 < ppSCSI.patch

where ppSCSI.patch is the name of the patch. Then you can do make config, make menuconfig or make xconfig, whichever suits you. The best thing is to build both ppscsi and the specific module you need, as modules. Besides these modules, you also need two scsi-modules; scsi support (scsi_mod) and scsi generic support (sg). The parport modules might come in handy too, allthough it should work fine without them.

After building the kernel and modules, installing them and rebooting, the modules should be loadable. Turn on your scanner, and load the modules.

 insmod scsi_mod
 insmod sg
 insmod parport
 insmod parport_pc
 insmod ppscsi

For a HP scanner (epst).

 insmod epst

For a microtec:

 insmod onscsi

The kernel should recognize it now, which can be checked with

 cat /proc/scsi/scsi

You should see something like :

    Attached devices:
    Host: scsi0 Channel: 00 Id: 00 Lun: 00
      Vendor:          Model: Scanner 300A4    Rev: 3.00
      Type:   Scanner                          ANSI SCSI revision: 02

or with the Sane utility

 sane-find-scanner

If these tools list the scanner, then the kernel can communicate with it. After that, it's up for the backend to support the scanner. If the kernel doesn't recognize the scanner, the best thing is to ask for help at the mailinglist at http://www.torque.net/parport

8.3. Any other hints if it doesn't work?

http://penguin-breeder.org/sane/mustek_pp has a section "troubelshooting" that might be helpfull.

8.4. What is the difference between sane-find-scanner and scanimage -L?

The only thing sane-find-scanner does is to send a SCSI inquiry command to all SCSI devices and put out information about all devices of type "scanner" and "processor". It will find any SCSI scanner, even those who are not supported. If you cannot find your scanner, it is probably a connection or kernel/module problem.

scanimage -L will only find scanners supported by a backend. If it doesn't find a scanner that is supported there may be a configuration problem.