Comment by burnt-resistor

Not all old scanners were just SCSI; there parallel port and proprietary adapter card scanners too.

Some cameras and printers also had SCSI interfaces: Opex MPS-40 mail sorting camera and NeXT Color Ink Jet SCSI.

And don't forget SCSI network adapters (NICs).

I'm wondering if there were a SCSI mouse and/or a SCSI to RS-232 adapter.