Tonight I assembled my cables I'll need to read my Rainbow 100B ST-251-1 hard drive I've had for a long time to get a backup.
I recently purchased a MFM ST-506 emulator which supports reading and writing old hard disks. To read the ST-252-1 I need the old standard two-cable (20-pin and 34-ping) to connect it to the emulator. This will give me a final backup, and also make it easy for me to snag the data from the drive.
Once I get this done, I'll switch to using the emulator to access the drive so I'll have continuous backups. It will also make it possible for me to explore Venix if the Venix disks that I just got are still good.... Still need to read them. I've hit a few snags in reading them from FreeBSD, which appears to have broken ISA DMA in 11.x, so I'll have to install 10.x instead of -current.
We'll see how it goes...