8 Jan
2017
8 Jan
'17
3:10 a.m.
On 08/01/2017 07:31, "Tony Duell" <ard.p850ug1 at gmail.com> wrote:
On Sat, Jan 7, 2017 at 11:37 PM, Adrian Graham
<witchy at binarydinosaurs.co.uk> wrote:
Hm, ok, that's today's task then. For V333 it could be that I just have the
pin numbers reversed but I'll double check. The diodes bothered me too and
I'm trying to think of a better way of tracing unknown lines on the bottom
of the board. My sponge-wrapped-in-tin-foil method isn't infallible.
Cheers!
--
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?
Evening all,
I wish I had the ability to take a board layout and turn it into a logically
laid out schematic but as yet I don't. Video sync on my Executel 3910 is
still running me round in circles so could one of you fine folk take a look
at this board layout drawn as best I can:
http://www.binarydinosaurs.co.uk/STCExecutelSyncCircuit.jpg
...and let me know what it does please? The chip on the left is a Plessey
I don't believe it's correct as drawn. For one thing you have V333, an NPN
transistor, with the collector grounded (and no -ve supplies on the circuit.
For
another, R322 is ridiculously low. And I would expect the anodes of the
3 diodes on the RGB outputs to go somewhere other than a resistor to
ground. 