In reference to your original question asking about printer parallel ports and SCSI:
Iomega Jaz drives and Zip100 drives had an adapter and software that allowed the SCSI drive to be connected using the "Jaz Traveller"(parallel port) adapter. It is not a fast way do access a drive (much < 2MB/s). I think it was SCSI-2 drive. If you can find one these Traveller adapters (see image in link it is the forest green dongle you see inline with the cable). The link shows that non-Iomega drives could be used with their parallel adapter but not an easy task.
I am not aware of any other vendors that were providing an adapter like this one. This tech is from mid 1990's when WIN 98SE was in use. The page mentions "Fortunately normal hostadapter drivers for the Jaz Traveller exists" you will need to reach out to the author to clarify that. This is not a complete answer to you problem but I hope it leads you to a solution. What version of windows are you using?
I still have my JAZ drives and adapter in a box somewhere. These adapters were a bit picky sometimes you needed to turn of enhanced features on parallel port in BIOS. Do post if you find something similar. A PCI SCSI-2 card would be a simpler (expected throughput 10MB/s).