Jack,
You can drive an HP-IB equipped HP7970E with an old PC that has an HP-IB card using Ansgar Kueckes HPDIR. I debugged it together with Ansgar. The rub is that it only worked well with an ISA HP-IB card running under Win98. The PCI HP-IB card running under XP uses a driver that causes timing errors and it skipped some records, and I don't think Ansgar ever bothered to fix it - we were happy enough to have made one solution work... The commands used to read and write from the tape are complex and tricky, and you have to get your timing right as there is hardly a buffer in the interface (128 bytes). And there is this weird parity thing, where parity has to be generated for commands on the HPIB bus, but not for data, or something of that ilk. If not the tape just hangs the bus. There are several GPIB emulators based on Arduino that should enable you to build an interface. You know me, I made several videos documenting the work on the 7970E tape: https://youtu.be/eCBxNhEzIfc?t=7m6s (tape interfaced with a PC running Ansgar HPDIR) https://youtu.be/5J8IbpJoeqk (shows how I sniffed the HP-IB bus to figure out how the commands worked - or didn't, also has a demo of sending a rewind command in the raw via a paddled-in program) https://youtu.be/YS9dGYUbNd0 (showing a demo with the tape attached to an HP-85, using an FPGA based gizmo to take care of the on-the-fly parity generation) https://youtu.be/rAsLwcq4RNU (fixing a loading fault on the tape drive) Although I love the HP 7970E dearly and want to encourage you to try your luck at it, that was a lot of work to get it to work on something it wasn't meant for. You'd have a much easier time bringing up a SCSI based tape. Marc Subject: (Classic Computers) HP 7970 1/2" 9-Track Reel-to-Reel Tape Drive Question: Anyone have experience talking to a 7970 tape drive from something other than an HP computer - something that does not have HP-IB??? How is that usually done?? Jack Harper Evergreen, Colorado
