I built a USB bridge for an old parallel port Zip 100 drive
Back in school, in my computer science class, I had an Iomega Zip 100 on parallel port. I used it to carry my own Delphi programs from home to show the others. That was a lot of fun, and I wish I still had that drive. I don't, so when I saw this one on Ebay for 10 euros plus shipping I bought it straight away. Mostly for the memories.
Current machines have no parallel port, so I built a small bridge for it. It is a Raspberry Pi Pico W with three SN74LVC4245A level shifters and a DB25 socket. The drive side was the hard part, since Iomega made up their own protocol there and it is not standard IEEE 1284.The Linux ppa driver turned out to be the best reference I could find, so I read it closely and tried to copy its handshake timing in PIO. Since my code follows that driver so closely, I plan to release the firmware under the GPL. The bridge then talks SCSI to the drive and USB mass storage to the PC, so the disk just shows up as a normal drive. No FAT parsing and no conversion, it is only a transport bridge.
The drive settled into PS/2 mode, which is the easy case. I get about 280 KB/s right now, and that is roughly what Iomega rated the parallel drive for. Their spec gave the number in megabytes per minute, which works out to about 250 KB/s. So the bridge is not the limit here, the drive is. I am fine with that.
TL;DR: DIY RP2040 parallel to USB bridge to get my old Zip 100 drive working on a modern PC.
Anyone else here still have a Zip drive somewhere?