I am pretty sure I used one of these keyboards on some TENEX system connected to the ARPANET back in the day. I remember the funny mix of key shapes. Maybe at BBN or ISI? The one I have now though I picked up surplus much later. As far as I can tell, it is in complete working order. The locking mechanism on the locking keys being the most fiddly.
I always try to use as much of what remains as possible. So, here that means the usual interfacing to 74-series TTL, and not directly to anything more complicated, as others prefer to do. Still, since the key switches are Licon magnetic valve, the keyboard has a ramp generator that requires ±12V, in addition to TTL's 5V. I used a boost converter bought off the Internet for USD 3.00, powered by a second USB port.
The cable for connecting to the terminal has a 30 position edge connector. (See Haata's photos of his, which are much better than any of my photos.) Mating connectors are also only around USD 3.00 a piece. But Digi-Key had a minimum order quantity, so even when I build a tidier version on a perfboard I will have some left over. I know these keyboards are still reasonably common. So, if anyone here in the States has an HP 264xx keyboard and wants a connector or two, drop me a line.
- hp_264xx_usb.jpg (443.45 KiB) Viewed 2121 times
