Linux NetMag #2
Titel: Zip Drive - Part II

Zip-Disk What to do, if you have connected a ZIP drive and a printer at the parallel port?
Create a special kernel for each device and reboot if you want to print or use the zip?
Say thank you to the modules! We do not need this for kernel 2.0.X

If you have already produced a kernel with ZIP support you would only need some small changes. If your kernel has not supported this drive yet, you should first compile one with these abilities (see issue LinuxNetMag#1 Zip-Drive).
As for a kernel without modules you need to include Now things that have a different configuration are shown below. If you have not already done you should activate the loadable module support:


Next you have to configure the parallel printer support as a module in "Character Devices":


The last change configures the Zip drive as a module, too. For this you activate it in "SCSI low-level drivers":


Also  "SCSI support" and "SCSI Disk Support" can be changed to modules but this is only recommended if you do not have a SCSI-harddisk in your system that you need during booting. The safest way would be if you say "y" here and compile the driver into the kernel.
After compiling the kernel and the modules with the command

>> make clean dep modules modules_install zImage
you rename the kernel (in the subdirectory ./arch/i386/boot/zImage) and copy it to / or /boot/ .
Then you include the new kernel with yast at and configure lilo that the new kernel will be available next booting.

Load Modules
After rebooting the system with the new kernel you can access the new modules. With
>> cat /proc/modules
you are able to see which modules are loaded at this moment. The module lpd corresponds with the printer which is often loaded.
If you want to access the Zip drive you will have to load the corresponding module. This happens (as root) with
>> insmod ppa
If the printer module was still active you would get the following error message:
lib/modules/2.0.3x/scsi/ppa.o: init_module: Device or resource busy
In this case you have to remove the printer module (as root) with
>> rmmod lpd
But this would only be successful if no printer jobs are in the spool, i.e. the printer has to finish all jobs before you are able to access the Zip.
If you managed to load the Zip module you would be able to mount it (as root) with
>> mount /dev/sda4 /mnt/zip
or if you configured the /etc/fstab you could mount it as a user with
>> mount /mnt/zip
After using the Zip you can restart the printer module after unmounting the Zip and removing the Zip module.
>> rmmod ppa
>> insmod lpd
You see it is not necessary to reboot any longer if you change between Zip and printer.