You sure the imm driver doesn't exist? I have a CentOS 6 system and if I do
it loads the imm module without a glitch. You need also the parport and parport_pc modules to work with parallel ports. I cannot test it right now, because I have not my IOMEGA 100 ZIP at hand, so I cannot provide more details. I remember the IOMEGA zip requires the /dev/sda4 partition to work.