In search of Three Rivers PERQ 1 Keyboard

Tony Duell ard.p850ug1 at
Thu Apr 30 07:42:04 CDT 2020

On Thu, Apr 30, 2020 at 6:40 AM Tony Duell <ard.p850ug1 at> wrote:
> > 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.

Digging around, I have found :

A hand-drawn schematic that I reverse-engineered of the keyboard PCB instelf

A .tar.gz file of PERQ PROMs/PALs. Most relate to the PREQ2 machines
(there's even a dump of the AMUX24 PROM for the 24 bit T4 CPU board).
But the PERQ1 keyboard mapping PROM is there.

I couldn't find a diagram of the keyboard cable so I took my PERQ1
keyboard apart and traced it out.

I am happy to provide copies of the above to anyone who wants them.
You'd be welcome to distribute them further. As I have a limited data
quota each month, in fact I'd rather send them out once and let
somebody else pass them around.

I do not recommend trying to copy the original keyboard though. I
susepct the encoder IC is totally unobtainable now. Note that some
PERQ backplane ('MOM') diagrams have an error on the keyboard
connector pinout, the signal to increment the DDS (diagnostic display)
doesn't appear there. My cable diagram shows it though. The DDS
diagram should be on bitsavers.


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