AFAIK it was just an A3000 with a tape drive. Commodore also made an 8-bit framebuffer (1024x768) and I don't know if X will work without it, but I think it was optional.
I don't know if the boot disks supported only one kind of tape drive, but If you can get your hands on an A3000 with a SCSI taper you could always give it a shot.
AMIX is even more mysterious than A/UX (which of course makes it very cool)
