The possibility exists improbably, however!
- Posts: 4090
- Joined: Mon Sep 26, 2011 10:56 am
- Location: Looking forward to summer in Somerset, UK...
The most fun I’ve had, is with a recreated Jupiter Ace and a ZX81 PSU. I used a RECOM DC/DC converter / switching regulator instead of a 7805 voltage regulator. It has a different type 3.5mm mono socket compared to a Sinclair computer. Because as you insert the plug, there is a momentary spark, the RECOM DC/DC converter gets upset and refuses to output any voltage.
Mind, the spark is impressive, especially if I’m a bit slow in plugging it in.
Hence now I power the ZX81 PSU down before connecting it. No damage has occurred to either the ZX81 PSU or the Jupiter Ace and it still works fine.
I plug the power plug into the motherboard socket before plugging the psu to avoid problems with sparking, none of my psu's spark in this way I've found.
I checked my ULA 2C184E motherboard and there's no output from pin 16 of the ULA.
My other motherboard seemed to have no 5V supply to the modulator but as the PCB track connects more or less directly to the regulator output I must've made a bad connection when I tested it because there was 5V when I tested it again.