and
@AC Rempt just in case you ever think of them i'll mention this for now..
the zip drive is basically in three generations with variations in each
100mb
both internal (scsi or ide) and external altogether were somewhat equally common,
you have to be a bit cautious with external ones tho due to the way that apple scsi is confusingly physically same as pc parallel [but obviously electrically absolutely incompatible] so one simple way to tell that apart is that the parallel zip drive simply just had the two rear ports alone with no visible slider switches down the middle but the scsi or "plus"(hybrid) variation had two small slider switches on rear to set the scsi bus itself]
250mb
can read/write 100mb medias as well,
there were both the 'classic' alike-to-100mb shell in matte sort of blue and modern more curvy shell in glossy sort of blue and the latter often is confusingly listed as eg "usb&scsi" online but that is *not* so as it is only a usb drive!
I don't know a lot more but others here would be happy to help in a new topic if you ever ask
750mb
someone else will have to check this for me but I think I recall that they could read 100/250 but had some kind of compatibility issues with writing to them,
and by now I somewhat certainly believe that scsi was completely dropped leaving you with just ide internally or usb and firewire externally