The Sinclair QL Forum

Still no problems after an hour. I run benchmark and some programs-games.
It also works well with the qubide clone card.

Derek_Stewart wrote: ↑Wed Jan 24, 2024 3:18 pm I have TMS4164-15NL DRAMs soldered to the QL board:

So the voltage regulator was not the only difference. To be honest, I already expected that you have different DRAMs. Thanks for the update.

lliont wrote: ↑Wed Jan 24, 2024 4:19 pm I think you mean KM4164A

Yes of course, sorry for the typo. The exact label is: "KM4164A-15"
The second line contains a three digit lot number followed by "KOREA".

lliont wrote: ↑Wed Jan 24, 2024 4:19 pm The KM4164B-12 work without a problem you can see in older pictures that half of the drams in my issue 5 QL are this kind.

Not surprising at all, because they are faster speed grade.
Cooling was sufficient to make your hardware work with the KM4164A-15, so the timing was already close.

lliont wrote: ↑Wed Jan 24, 2024 4:19 pm I found also 3 ics KM4164B-15 to test

Good. Those should be closer to KM4164A-15, but might still be a little faster.
I have not been able to find datasheets for the "A" version in order to compare with "B".
The best would be to theoretically find out why the timings failed, and not just rely on trial and error.
If I find an hour on the weekend, I'll try my brandnew scope on it.

lliont wrote: ↑Wed Jan 24, 2024 6:03 pm Still no problems after an hour. I run benchmark and some programs-games.
It also works well with the qubide clone card.

Thanks for all the work! I'm now waiting for the Altera adaptor to arrive. And your updated JEDEC file of course.

And let me warn you about the GoldCard and SuperGoldCard. Both do not implement the 68008 bus timings correctly, and failed even worse with my mainboards and the ULA replacement. If someone with a system that already works with your latest PCB / CPLD could try (S)GC, that would be good. Derek?

Sorry Peter, I am unable to test the ULA replacement against my GC.

Peter wrote: ↑Wed Jan 24, 2024 7:41 pm And let me warn you about the GoldCard and SuperGoldCard. Both do not implement the 68008 bus timings correctly, and failed even worse with my mainboards and the ULA replacement. If someone with a system that already works with your latest PCB / CPLD could try (S)GC, that would be good. Derek?

Sorry, I have not got a SGC.

Hi Leon,
thanks for your investigation and the CPLD update. Unfortunately it has become worse, inasmuch the huge Minerva letters are also corrupted now.
I have soldered a socket for JTAG, so I can update quite easily at the moment. If you have further ideas, I can test.
All the best
Peter

This is really strange, no ideas right now, if I had your QL maybe I could do something.
I think it is time for a refund.

Hi Leon,

The ram in my Issue 5 QL is TMS4164-15NL, which works well, would the quality of the ram have a problem with the CPLD code?

@Leon

As I have a range of QLs of all three motherboard versions as well as both GC and SGC, perhaps I can also do some testing if I could purchase your ULA replacements?

I'll PM you

Just for reference, I have KM4164A-15 in my QL running well with the ULA replacement.

Stephan