The Sinclair QL Forum

Back to the one with the bootloop... I discovered that the bootloop is the same whether the ROM pack is plugged in or not, so does that mean it's somehow not communicating with it? i.e. that it's died. I've re-touched all the solder joints and short of removing and testing all the 4 LS244/LS245 I'm ...

SRAM issue I found on my machine was the lack of the POWER-GOOD from the power supply, listed as "shutdown" on the pinout. Check VCC (from the 3V battery) and /CE (from PSU via MOSFET on the left of the board) on the SRAM chip. Thanks. I'm not sure if my NOS board 3v battery is properly c...

Thanks for the suggestions. After much re-seating, cleaning etc, I do sometimes get a different message: INITIALISATION (c) ICL 1984 SYSTEM RESET AHPk (at the bottom) AA CTRL - FAIL Then that message goes away but the bottom AA CTRL - FAIL remains and it says 'Loading saved store', then it resets it...

Some progress... I had a spare NOS daughter/CPU board but that was just giving me a black screen. I tried various combinations of ROM chips (ICs 4-7) and with one combination it gets much further but goes into a boot loop, thus: Chequer pattern Black screen/white screen a couple of times Vertical st...

Thanks. I did try unsuccessfully to find that info... Hmmm, data registers. I happen to have a spare NOS main board, so swapped them over (using the same daughter board) and the 3 stripes are still there exactly the same, so that's either a coincidence and both main board have the same issue or it p...

I made my interface card today, here it is: 20240120_201159.jpg Before I even had a chance to test it I found that my working Merlin Tonto has quietly died in storage and now shows 3 vertical white stripes. Instead of cluttering this thread, here is a new one on that: https://qlforum.co.uk/viewtopic...

Just got my Merlin Tonto out to try out Stephens' C1 disk interface clone. I didn't get as far as plugging that in though, as I get a chequered pattern and then this screen with 3 vertical lines on boot: 20240120_201219.jpg It was working a few months ago when I packed it away. Likely RAM issue? I c...

I read that too on the WD1770/WD1772 re the stepping. I suppose I could just try a WD1770 when I've built the adapter.

Thanks Stephen and Pr0f.

My PCB's should arrive soon. I have all the other components together and will temp pinch the WD1772 from my Trump card for now. Obviously the ICL Basic is different in many respects to normal QL basic, I wonder if it would be possible to run QL basic somehow on an OPD? Or would it be too restricted...

Have you tried booting it with Minerva? That will report some codes and from them you can (usually) work out which chip is bad.