Re: 1240 Logic Analyser display problem

Kevin Wood G7BCS

Have you tried disconnecting the VSYNC pin from the 5321 chip (i.e.
remove the chip if it's socketed) and then checking for a
short-to-ground, or any output from the (now floating) pin?
Ahh, good point. I should try that. It feeds the next stage through a 10k
resistor so unlikely it's being dragged down but you never know...

Personally, I'd swap the thing for a CPLD or a board-o'-TTL, but that's
only because I have copious stocks of both. A couple of TTL counters
(HC4040?) and comparators should just about do it.
Yep, the thought crossed my mind too. Actually, the H&V counters are
already on the board, thinking about it. Not sure I want to hack it about
that much though.


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