In search of Three Rivers PERQ 1 Keyboard
ard.p850ug1 at gmail.com
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.
More information about the cctalk