I;'d love
to see you fit anything into the connector of an HP120 or
HP150 keybaord. The connnector, BTW, is a 6 pin RJ11....
Okay, then how about fitting one inside of an RJ25 (isn't that a 6-
pin RJ11?) "crossover" adapter?
What good would that do? This is not an interface module that connects
between the HP120 and an unmodified HP150 keyboard (if it was, I wouldn't
have bolted it to the keyboard, cf the interface for the 262x keyboard I
described last week). It's a modification to the HP150 keyboard tht
electrically connected by a piece of 14 way ribbon cable and a DIL header
in place of a 4024 chip on the keyboard PCB (Desolder the chip, solder in
a socket. P,ug in a 4024 to return the keyboard to the original HP150
circuit, or this modification board to make it work with either the HP120
or HP150).
Making an interfaec to connect between the HP120 and an unmodified HP150
keyboard would be a lot harder (and would almost certainly need a
microcontroller). You'd have to scan the HP150 keyboard (generate clock
and reset pulses, grab the state of the keydata line), then store the
state of all the ekys and transmit them to the HP120 in accordance with
the clock and reset pulses from that machine.
I did consider doing this, but the modification to the keyboard turned
out to be a lot easier.
-tony
