Decwriter II

From: Marvin <marvin_at_rain.org>
Date: Mon Mar 29 12:29:54 1999

Geoff Roberts wrote:
>
> Anyone know where I'd find a circuit diagram for a Decwriter II?
> Preferably in South Australia.
> I have one that thinks it's permanantly out of paper.
> (No, it doesn't seem to be a microswitch)
> I suspect it's just a stuck logic state in a 74xx ttl chip, but a circuit
> will make it a lot easier to find.....
>
> Alternatively, if this is a common fault, anyone know which chip is
> implicated?

It looks like the Paper Out signal goes into J3-6 of the keyboard assy. and
goes into the main logic board on J2-AA/BB; the main board test point is
TPZ17. It looks to be lo true judging by the pullup resistors. From there,
it goes into E37 pin 12 (7474) and comes out on pin 9 as MPC8 Ready H. The
test point is TPV20. I might add that the logic board I am looking at is the
M7728. I can scan in that portion of the schematic if you need it.
Received on Mon Mar 29 1999 - 12:29:54 BST