The Sinclair QL Forum

Well, I had a bit of a moment earlier today - plugged a second hand QIMI into a working QL, and had a black screen...

Tried turning off and back on again, and just got the dreaded buzz of death from the QL speaker...

Oops !!

Looked at the pins on the QIMI - all were in place - thought it must be a defective QIMI.

Went to remove the QIMI and burnt my finger on the ULA plugged into it. Only at this point did I realise that the former owner had plugged an 8301 CHIP into the QIMI instead of the 8302 !!

No wonder it overheated...

Still - change the ULA for the correct one, and the QL and QIMI all work fine (phew).

Just a reminder when fitting any internal expansion boards - if it plugs into a chip socket - use the chip you remove to go into the top of the expansion board.... !!

That sounds like a close run thing!

I've come across a couple of second hand boards where a chip has been inserted incorrectly in a socket...
So now I check before powering up for the first time

Mark

I thought it might be a useful reminder to people who get one of the QL-SD Interfaces for example - especially as there are up to 3 different makes / notations for each of the QL chips.

It was only recently that I realised that the 8503 chip (!) was another notation for the 8049 !!

Wonder what the difference is...

RWAP wrote: Wonder what the difference is...

Vendor and naming only, hopefully. The naming is about the only piece of creativity left possible if you're trying to sell compatible chips. In this case NEC's creativity compared to Intel's

NEC has been famous to invent their own names for chips well-known under different designations - I wonder if this is related to copyright issues. Their Z80 was christened 780 (see how they even tried to keep the name visually similar to the original...)

In your specific case it would be interesting to know if the overheated ULA survived as well?

Ha - I am not even going to try it - there is a melt mark on the top, so I doubt it!