CPLD replacement for ZX8301

[lliont]

Of course, thanks
I will send you later a board, hopefully with a version that works with SGC if I succeed to fix it, for free too
Also a board with the 128K

[QLvsJAGUAR]

Whats about the Thor OS, does it work here and can use the colours?

I'm a bit late joining this party. Yes, the Thor OS ARGOS of the Thor XVI machine supports 16 colours as does the hardware of the Thor XVI. My machine is stored away in boxes, but here's a screenshot of the colour palette in MODE 12 (weird name for 16 colour mode): https://1drv.ms/i/s!AlrOgIl02FDCgrNMOVe ... g?e=s50ufp

[QLvsJAGUAR]

Whats about the Thor OS, does it work here and can use the colours?

I'm a bit late joining this party. Yes, the Thor OS ARGOS of the Thor XVI machine supports 16 colours as does the hardware of the Thor XVI. My machine is stored away in boxes, but here's a screenshot of the colour palette in MODE 12 (weird name for 16 colour mode): https://1drv.ms/i/s!AlrOgIl02FDCgrNMOVe ... g?e=s50ufp

Plus, there's a chapter in a video where one sees the CST Thor XVI 16 colour video mode (MODE 12) in action:
https://www.youtube.com/watch?v=zVZICdYj_38&t=129s

[Derek_Stewart]

Hi,

Nice video.

I used to know someone in the North of England that had a Thor 16, seemed run quite smoothly.

But the Gold Card and later on, the Super Gold card, out performed it. Pity, I liked the Thor, I have a Thor 1 case, disk drives and rom board.

[llion]

Does GC/SGC takes QL's rom address space? I think it does.
If this is true, I know why the cpld replacement is incompatible with these cards and I can fix it.
It hasn't got to do with any dram timing.

[Derek_Stewart]

Does GC/SGC takes QL's rom address space? I think it does.
If this is true, I know why the cpld replacement is incompatible with these cards and I can fix it.
It hasn't got to do with any dram timing.

Hi,

See Marcel's Blog about the SGC startup:
https://www.kilgus.net/2018/11/14/super ... -sequence/

[martyn_hill]

Good morning everyone!

Having received one of Leon's excellent (basic) ZX8301 ULA replacements recently, I proceeded to test a number of configurations.

Full test results appear below but overall, the replacement ULA works perfectly in both my Issue-5 and Issue-6 QLs until a Gold or Super Gold Card is inserted, which aligns with earlier feedback.

The unit arrived promptly, well packaged and is clearly built with extreme care and attention! I'm confident that, in due course, we can help Leon uncover the Super/Gold Card incompatibility, but for now, the replacement ULA is already a very welcome addition in my rapidly decreasing pool of ZX8301 originals!

Test Results
QL Specs:
a) Issue-5, UK, "NEC 4164 -3" DRAM, original ZX8301 "2310", QL-SD Minerva ROM (1.98), unknown SM Power Regulator
b) Issue-6, UK, "TMS4164-12NL" DRAM, original ZX8301 "2310", QL-SD Minerva ROM (1.98), Tetroid SM Power Regulator

Tests:
By 'OK' I mean to say the QL booted as expected and there were no observable glitches on the display over a few minutes until I powered-down the QL again. In some cases I ran a few pieces of software and left the QL on for a longer period of time - again with no observable issues.
When failed, the observable results varied between Gold versus Super Gold cards - see below.

1. QL a) no expansion - OK
2. QL b) with 256K 'homebrew' 8-bit mem exp. - OK

I then focussed on the Iss5 QL, as the motherboard version didn't appear to affect the results:
3. QL a) plus QIMSI - OK
4. QL a) with 768K Trump Card (Miracle) plus QIMSI - OK

5. QL a) with Gold Card (Tetroid) - with or without QIMSI - FAIL - colourful patterned screen immediately after power-up and hangs without ever displaying Minerva logo
6. QL a) with Super Gold Card (Tetroid) - with or without QIMSI - FAIL - gets as far as Minerva logo before 'speckling' the screen and hanging

Also worthy of mention - seems that the replacement ULA offsets the video signal by 1 or 2 scan lines down - causing the last couple of lines to fail to display when attached via the RiPico QL VGA adapter to my HP 21" VGA monitor.

It's not noticeable via an RGB to HDMI converter to the same monitor, but does suggest that anyone using the (excellent!) RiPico VGA adapter might also spot the last missing scan line(s). It's quite possible that a monitor adjustment would correct this - my own HP monitor wouldn't budge, however.

Thank you Leon!

[lliont]

Thank you, I'll shift the display up 2 lines.

[Peter]

Does GC/SGC takes QL's rom address space? I think it does.

What do you mean by "take"? It does access the ROM address space 0 ... $FFFF of course.

It hasn't got to do with any dram timing.

But with the bus timings generated by (S)GC! Which are not identical to the 68008. For example GC changes the address lines too early at the end of a bus cycle, which caused me headaches when I designed QIMSI.

[lliont]

Thanks, any other hint?