Nascom 2 keyboard connector

[Jules Richardson]

On Fri, 2005-06-10 at 00:09 +0100, Tony Duell wrote:
>
> Alas I don't have a Nascom 1 schematic...

Well the Nascom 1 *keyboard* schematic is online on a Nascom site along
with the rest of the schematics for the Nascom *2*.  Which does seem a
bit strange, as though maybe the keyboard schematic for the Nascom 2
isn't part of the standard documentation.

Not that there appears to be much difference between the two; the Nascom
2 one just has the extra row (and no doubt totally different key matrix)
and this keyboard sense line (which as you say probably isn't used by
the software anyway).

> > In all it uses 13 out of the 16 pins on the keyboard PCB. Pins between
> > the keyboard and CPU board *do* match up 1-1, it's just a case of
> 
> WHich 3 signals are not used? I would guess at Q2 and Q5 and one other.

Yep, Q2, Q5, and /NMISW 

(Q0 drives the reset inputs for the keyboard's on-board counter, whilst
Q1 provides its clock pulses)

cheers

Jules