In search of Three Rivers PERQ 1 Keyboard

Tony Duell ard.p850ug1 at
Thu Apr 30 00:40:46 CDT 2020

> Thanks in advance for any leads or on-topic discussion of the keyboard protocol to tide me over in the meantime...

I'll see what I can find, I am sure I have some notes on it somewhere.

>From what  I remember, the keyboard interface is 8 bits + a strobe
line. Bottom 7 bits are essentially the ASCII code of the key, the MSB
is the Ctrl key (which does not affect the bottom 7 bits).

The reset button is also on the keyboard case (at the back of it) on a
PERQ 1, it just grounds a line on the connector.

There's also the DDS (diagnostic display). This is a 3 digit decimal
counter + 7 segment displays. Cleared to zero by the reset button,
incremented by a signal on the connector. The machine will run without
it, but it's very helpful to know what the microcode thinks is wrong
when the PERQ won't boot.


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