The Sinclair QL Forum

Hi there, could someone give some advice pls - on starting my original QL with Minerva 1.98 ROM fitted it checks the memory, gets to the start screen (see photo) and then won't go any further - just hangs and is unresponsive. I've tried a different Minerva ROM and JS ROMs with the same result - pressing F1 or F2 at this stage does nothing. Any advice would be much appreciated.
Thanks Keith

Sounds like keyboard membrane is knackered!

Possibly nothing to do with the issue, but there is no red in your picture - which seems a little odd.

As XorA says - keyboard membrane, or possibly IPC chip or the Zx8302 chip not communicating - so the keypress isn't getting detected.

I'll check the chips you mentioned - it's definitely not a membrane issue as that is working fine, and even if the membrane was broken after a short time the Minerva ROM goes to the TV screen anyway, regardless of whether a key is pressed or not - the Minerva screen is the oen that always comes up on start up - it's a Minerva ROM I got from Chris Perkins and I replaced that with a spare so I knwo that isn't the problem. But I'll definitely check out the chips you mentioned.
And I'll let you know what the outcome is, thanks guys

Pr0f wrote: ↑Sat Jan 28, 2023 10:56 pmPossibly nothing to do with the issue, but there is no red in your picture - which seems a little odd.

Yes and looking at the picture there are white pixel columns so doesn't that suggest a ram issue that would affect processor operation & screen?

The only thing is - to get to that screen it must have done the memory check and passed it and reported 128K

so in my experience writing emulators what makes minerva lock up at that point is missing irq or the irq register not being read properly.

Are there any other upgrades to this machine or is it just the Minerva ROM ?

Well I have solved the problem - I have replaced the co-processor next to the microdrive 1 with a hermes 8049 co-processor I had laying around, and now the QL starts up as per normal and doesn't hang on the start on screen, so it must have been the co-processor. Anyway it was a nice easy fix without any outlay as I already had the Hermes, so happy days . Thanks for all the suggestions.

Glad you got it fixed