Author Topic: Televideo 950 USB conversion build  (Read 1457 times)

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Offline chiffre

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Televideo 950 USB conversion build
« on: Sun, 08 March 2015, 03:00:34 »
I have a Televideo 950 terminal keyboard with a 4P4C plug as its interface. To make a long story short, I want to make a Teensy-based converter so it can be used with modern computers via USB. I hope that by posting here others with similar equipment will have something to reference.

I've found similar threads on this forum that describe how to do this same project with old mac and WYSE terminal keyboards with 4P4C plugs. But each keyboard is slightly different. 

Here is what it looks like in all it's early 80s glory.
93128-0

Right now I have the 950's schematics and the output appears pretty simple, but I really no expert, and I'm looking for some expert advice on what these ports are used for. Once I know for sure I can start on the Teensy portion.

The cable appears to be a serial connection with tx and rx, power and ground. Obviously I'll have to have an external power supply, but could I theoretically just wire it straight to standard serial with no teensy (USB to serial adapter)? 

P1(tx) --- out?
INT(rx)  --- in?
VSS  --- 12v
VCC --- Ground

Any insights into the schematic would be helpful

Thanks.

Offline rowdy

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Re: Televideo 950 USB conversion build
« Reply #1 on: Sun, 08 March 2015, 04:37:46 »
Welcome to Geekhack!

I can't help with your questions, not being technical enough in that way, but that's a wonderful keyboard, I hope you can get it working :)
"Because keyboards are accessories to PC makers, they focus on minimizing the manufacturing costs. But that’s incorrect. It’s in HHKB’s slogan, but when America’s cowboys were in the middle of a trip and their horse died, they would leave the horse there. But even if they were in the middle of a desert, they would take their saddle with them. The horse was a consumable good, but the saddle was an interface that their bodies had gotten used to. In the same vein, PCs are consumable goods, while keyboards are important interfaces." - Eiiti Wada

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