Does my parallel port work correctly?

Since we already have installed the kernel sources, see section 2.1, there should a kernel documentation in the directory /usr/src/linux/Documentation/. You might want to take a look at the file parport.txt. This file describes the parallel port unter linux in more detail. There you will find e.g. that if you have a proc file system (SuSE 7.2 and presumably all modern distributions will have that) you can find status information about the parallel port in the directory /proc/sys/dev/parport. The exact directory and file structure there should look somewhat like this: (Quoting from parport.txt)

parport
|-- default
|   |-- spintime
|   `-- timeslice
|-- parport0
|   |-- autoprobe
|   |-- autoprobe0
|   |-- autoprobe1
|   |-- autoprobe2
|   |-- autoprobe3
|   |-- devices
|   |   |-- active
|   |   `-- lp
|   |       `-- timeslice
|   |-- base-addr
|   |-- irq
|   |-- dma
|   |-- modes
|   `-- spintime
`-- parport1
    |-- autoprobe
    |-- autoprobe0
    |-- autoprobe1
    |-- autoprobe2
    |-- autoprobe3
    |-- devices
    |   |-- active
    |   `-- ppa
    |       `-- timeslice
    |-- base-addr
    |-- irq
    |-- dma
    |-- modes
    `-- spintime

The 'files' there are not real files. If you read them, the kernel will give you some status information. This is just a convenient way of making status information available to all the users and applications on your system. In order to see if you parallel port is working in EPP mode or not, you could proceed as follows:

mathplanet:~ # modprobe parport_pc
mathplanet:~ # modprobe parport
mathplanet:~ # cd /proc/sys/dev/parport/parport0/
mathplanet:/proc/sys/dev/parport/parport0 # cat modes

As outport the last of the above commands produces:

PCSPP,TRISTATE,EPP

That looks good. EPP mode has been activated for the first parallel port. For the second (if there is one) you would just write parport1 instead of parport0 in the above example and would receive current status information on the second parallel port. You can proceed similar in order to get information on the used interrupts and base addresses by using cat irq or cat base-addr in the appropriate directories. So if you find your parallel port is set to EPP mode that can no longer be a cause for errors. So lets proceed.