30 May
2004
30 May
'04
12:28 p.m.
My Lilith workstation keyboard seems to have taken an "electric"
beating, i.e. a 12 v to 5V short.
The wiring inside the machine was not the best......
It took out the 8035, a 74ls373 and, much worse, an unknown to me Exar
IC 22-908-03, datecode 1983
How many pins does this have?
THis sounds a lot like one of the 2 semi-custom ICs used with a
Keytronics capacitive keyboard. I've seen 22-908-3B and 22-950-3B used in
the PERQ 2 series and elsewhere. They have 20 pins each. The former is
the (latching) sense amplifier between the 8 keyboard row lines and an 8
bit input on the microcontroller.
Some later Keytronics keyboards have a 40 pin chip that contains both the
sense amplifiers and the column drivers. The number for this eludes me at
the momnet.
You might be able to get a replacement for these from another Keytronics
keyboard (e.g. a PC one).
The first two are easy to replace, the Exar is much worse.
Anybody have a pinout, a datasheet or an idea just what it might be ?
I should be able to find pinouts for the PERQ keyboard ICs.
Incidentally, I assume there's an EPROM in the keyboard (The 8035 has no
internal ROM, the '373 sounds like an address latch). Did this survive?
Do you have an image of it?
-tony