I never owned a Jaz drive, but I did own an SCSI ZIP100 drive from "way back when". I also scrounged up a USB ZIP100 drive that still works with the Mac today, and will still read disks more than 25 years old.
I'm not sure about the drivers on Jaz drives, but I do know that a Mac-formatted ZIP disk has an "on disk" driver. That is, no "OS driver" is needed. How this would work is...
- boot the Mac
- Mac "polls the buses" to see what drives are connected and what drivers are available
- Mac finds the ZIP drive (with the disk in it), reads and loads the on-disk driver, and then is able to mount the disk on the desktop.
So... I'm thinking that if one has Mac-formatted Jaz drives, the process may be the same.
Of course, you have to have the Jaz drive connected first so the disk spins up at boot time.
Not sure how this would work if the Jaz disks one has are NOT Mac-formatted (i.e., are in a PC/Windows format).
I'm wondering if it might be possible to access these through bootcamp (although I wouldn't install bootcamp just to access them).
Or... perhaps using an emulated setup such as Parallels or VMWare fusion?