The Sinclair QL Forum

On another look at them - yes all 27(x)128 - so 16K size.

I thought I'd spotted a 27256 in there - but just my dodgy eyes!

Probably all of those! Mixture of speeds and sizes there!

I've used 27 and 27C (cmos) varieties. On a stock QL - the 200ns parts should be ok.

I've also used 32K and 64K flash chips with eprom pinout too

Do you need so many address lines for the PIC?

Are you using it as memory from the point of view of the QL accessing it?

Where do we start? Are you connecting a pic pin directly to the QL address bus? If so - what settings have you enabled on the PIC pin besides telling the PIC it's an input? Did you disable any possible analog function on those pins? What about week pull down / pull up? What's your application? What ...

dilwyn wrote: ↑Wed May 29, 2024 11:32 pmWow!

I remember being slightly "gob smacked" when Wolfgang showed me this at the 40th celebration, wired up to mouse, keyboard and monitor and working! Although it is an interface to the Black box QL, it is fully capable of running autonomously as a complete computer.

possible issue with the edge connector (like a pin that's bent and shorting out maybe?)

ah - so the JM and Minerva ROM's are in 2 different QL's ?

The only possibility I can think if is if your Minverva also has TK2, and the floppy interface is set for the ROM port address...

Nice one

Well done on the progress with the DRAMS - so now probably just a single faulty chip?