When booting with the Red Hat floppy, the parallel zip
drive (via scsi4) is not detected, probably because
support is not in the kernel. (I happen to know that
you have to use scsi to access the parallel port zip).

When I select, during installation at item "SCSI
Configuration", "Do you have a SCSI adapter? Yes" and
"Iomega PPA3 (parallel port zip" + "Autoprobe", I get
the error: "I can't find the device anywhere on your
system!". Virtual console 3 (Alt-F3) reveals:
"* running /bin/insmod /bin/insmod /modules/ppa.o"
"* insmod failed!"
Note the double /bin/insmod, which imho is an erroneous
call. However, when I try in Alt-F2 console:
/bin/insmod /modules/ppa.o
I get the error: "Cannot find archive member ppa.o:
file does not exist in archive".
Note that /modules is properly symlinked to the right
directory on the, also properly mounted, cdrom.