The Sinclair QL Forum

If the ROMs were bad you'd get four stripes as they'd fail their CRC checks.

I wonder if a capacitor has gone bad and you're getting noise on the power rail. Something's very screwy.

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.

If the ROMs were damaged then you'd get 4 lines as this is when they fail their CRC check. If it's getting to the Iinitialising page then it's actually booting "fully" before resetting. i.e. it's passing the power on tests, including memory test (but this is rudamentary at best). I would r...

You need the ROM pack and the telephony module to fully boot, it will hang at a blank screen otherwise. It doesn't matter about the 9V battery, that merely keeps the real-time clock going. The 3V battery keeps the "Permanent Store" SRAM energised. It isn't required to be OK. If the content...

Here are the diagnostic stripe meanings. I'm pretty sure I posted them elsewhere.


Three stripes = "Data Registers" whatever that means. Maybe some flop-flops somewhere?

And is it possible Stephen, if in your improved/upgraded interface that it could use the more common WD1770 instead of WD1772? I've no idea what the differences are between the WD1770 and the WD1772. If they're not software compatible then the ROM would have to be re-written. It looks like Charlie ...

There's the Retro Computer Museum in Leicester: https://retrocomputermuseum.co.uk/

The Cave doesn't (yet?) do external events.

Is that http://www.nwcomputermuseum.org.uk ? Because the website doesn't work at all atm. There is a Facebook page with contact details, but little by way of actual information and pictures that I could glean from a quick visit. It's also so s-l-o-w as to be pretty unusable. If anyone from that are...

Finding a small computer museum and asking if they could be a venue could be a good plan as they would have the facilities to help with any equipment and knowledge of what's required (such as power sockets!). Some will also have classroom type areas they can use for this sort of thing. They could al...

Well, the floppy formatted on the C1 interface with the modified ROM passes every interoperability test so I think it's safe to publish.

Note that to use it with the OPD a floppy has to be first formatted on the OPD as the format isn't the default used by MSDOS or the ST.