Just about any 50 pin scsi drive less than 4Gb in size will work with version 2.0 of the OS. You are in luck even without the 590 install disk because 2.0 upwards versions have native support for scsi.device (which is the A590 scsi controller). Just boot from the 'Install' disk of version 2.0 or later an open HDToolbox to format the drive. You can do null modem networking with a PC with 2.04 roms but you might want to just throw in some 3.1 roms as all the better internet apps will need at least 3.0 of the OS. You might be able to softboot into 3.1, though I've never been able to manage this from 2.04 roms and you'll need a 3.1 rom image anyway (which implies having the physical roms).
