I've been looking at these keyboards for a little while now and finally bit the bullet.
Got this one from an IT supplier, and I'm gonna admit that I paid too much for it. I've got a familial connection to HP and wanted their logo in my collection in some form and this was about the cheapest way to do it. Since I wasn't able to find a ton of info on these out there, I figure I'll share what I find out as I go along.
The keys are pretty sensitive to off center presses, but feel good when hit directly on. That makes the weird ass profile of the keycaps make a bit more sense and why they went overboard with the stepped keys. The layout is weird, befitting a terminal board, but I do like the color of the legends. I'll get my macro lens out later and get a close up shot of the printing and somebody can identify the method.
Just one big ole foot on the back here. There's a RJ socket on here and the label says it's a 12v system.
If you're going to pull the keycaps on one of these, rock the puller up or down before you apply pressure upward. You run the risk or pulling the switch slider from the barrel, and it's a pain to separate a keycap from the slider if you do that.
That's a hell of a lot of solder points back there. Each switch get's four solder points and there's a diode for each switch. So if I ever get this up and running, it should have NKRO.
Sticker outside says Taiwan, this one says Japan. I'm gonna guess the plate/switches/board were made by Fujistu and then sent out for final assembly. I feel like this is greater than the usual number of ICs for a keyboard. Not a lot of luck getting specs on the chips, just by googling.
These are Fujistu Leaf Spring switches 3rd Gen of the clicky variety. They feel pretty good if you hit them straight on, but bind off center pretty easily. I hope a little lube will help with that, but it will take some experimentation. More info and pictures to come as I get further with this project.