deskthority

I've finished up with the last of the five terminal keyboards I've somewhat randomly accumulated in recent months. This one is a Televideo 935 terminal board (at least that's what it says on the PCB). It has white linear Hi-Tek 725 Space Invader switches that are kind of cool I think.


It's nice to be able to use these boards on my Windoze machine - I guess I'll just rotate though them for a while. I think the really fun part, however, was just the process of working on them!

Wow. Those rows and columns look very easy to trace. I wish every keyboard had a PCB layout like that.

ohaimark wrote: Wow. Those rows and columns look very easy to trace. I wish every keyboard had a PCB layout like that.

Yes, it's a nice matrix layout for a change! The Shift, Ctrl and Funct keys were a little oddly routed, but the Televideo folks seem to have made the effort to produce a pretty straight forward matrix which is definitely not the case for some other boards I've seen!

Great series of posts OIN. Really great stuff, thanks for posting them.

Do you have a closeup of how you did the teensy wiring? I could trace out myself, but this would save me a lot of work if I ever get around to restoring my TV935!

orihalcon wrote: Do you have a closeup of how you did the teensy wiring?

Sure, happy to post. These are the matrix I traced out and then the corresponding pins on the main IC. I was too lazy to rearrange the matrix diagram so that the letters and numbers would line up in order on the IC pins.



One minor note - when I wired the existing Caps Lock LED to the Teensy, I had to desolder a resistor to isolate the LED from the IC pads. Got lots of wonky key presses when I first hooked up the LED.

I was having a hard time tracing out the matrix myself. I soldered it up last night and this appears to be just what I needed!

Thanks so much for taking the time to post these details. This will be a huge help in converting the two Televideo boards I have

snacksthecat wrote: I was having a hard time tracing out the matrix myself. I soldered it up last night and this appears to be just what I needed!

Thanks so much for taking the time to post these details. This will be a huge help in converting the two Televideo boards I have

I'm glad it was helpful! These are very cool boards, and it appears you've found an excellent stash of them!