QVT-101 terminal keyboard

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neazoi

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Hi I have an old QVT-101 terminal, purchased at low price due to the missing keyboard.
The keyboard schematic is shown here.
The problem is that it uses this microcontroller inside to perform the matrix scanning. It seems that there is only one signal line, i.e there is no signal and strobe thing.
Any information on the protocol used and if there is a project that can replace this with a PS/2 or USB one, would be useful
 

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Its a DEC VT100 clone and in no way compatible with a PC keyboard.
The best you might manage is to build a PS/2 or USB to serial converter and use a big look-up table to convert the codes. The VT100 keyboard codes are well documented but some keys send a sequence of several bytes. To be honest, for a 40+ year old terminal it probably isn't worth the effort.

Brian.
 

    neazoi

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So any VT100 keyboard will do, not just the one came with it?
Is it actually a serial keyboard, output TTL signal levels?

If it is plain serial data, maybe I can use the RS-232 or TTL signals out of this thing http://cb2.qrp.gr and use it's terminal emulator program http://cb2.qrp.gr/usermanual/#9_The_communication_program_CBTerm_mini_ as input to the keyboard connector.

But I do not know it the connector accepts plain TTL serial data or something else.

Maybe I can operate this from the serial port directly using a VT100 emulator (PC with program).
Or it won't accept "local" keyboard commands if I operate it that way?

Lots of questions...
 

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I'm not sure what protocol it uses, the last time I used a VT100 was in the early 1980s!
Don't confuse the keyboard with the terminal serial port. The VT100 is a serial terminal with an RS232 port and emulator programs will use their own serial port to mimic the action of the VT100 but what you are needing here isn't the serial port, it's the keyboard port.

It clearly uses TTL levels and transmits and receives on the same wire but it won't be standard 8N1 data if it's duplex.

Brian.
 

    neazoi

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