Blizzard PPC for 1200 issue

[KronusOfChaos]

So I have an interesting issue with a PPC 603e 1200 accel card. So this is basically what happens if I put the logica diag roms into my a1200 with the accel card it boots and everything is seen in the logica diag system configuration menu. It sees the 040 processor and memory.

Now if I put my 3.1 rom back in I get black screen and if I push the num lock 5 or 10 times it locks either on or off. From my past experience this means the processor isn't functioning. Also tried to get to the menu on the PPC via escape and still nothing. This happens with or without ram installed.

Anyone have any ideas?

Thanks.

[emufan]

and 3.1 rom does work, when you remove the accelerator?

[KronusOfChaos]

Yes. The 3.1 rom works fine when I remove the accelerator. Also the card was working fine for a month and slowly went downhill and started getting harder and harder to startup with the machine. So lets say the first week I could soft reset twice and it would boot fine and run. The next week it would take 3 resets to do the same. etc. Until now this is where I am.

[Viserion]

Not an expert, but it could be that one of the CPUs needs reballing.

When that happened to my Cyberstorm, I could get it to boot if pressing the 060 (on my card), but more often than not when not pressing on the CPU.

Maybe worth trying, to at least rule it out as the cause.

[emufan]

while it may be the hardware issue - what makes the logica rom work but not 3.1.
maybe mark_k or Toni Wilen may have a answer to it.

[KronusOfChaos]

Viserion that's an idea. I'm pretty good with a soldering station, but not that good...lol... But it is very strange that the Logica can see it while the 3.1 rom's can't. Or should I say that I can boot into Logica rom's system, but the 3.1 rom's can't. And once in, I can show system info and it see that I have an '040 processor and memory.

[Viserion]

Could it be the PPC part that is not working. What sort of OS are you booting into when using the 3.1 roms.

I don't know anything about Logica roms, and how they work, so just throwing out ideas here.

Should not hurt trying the "press down CPU technique" so I would give that a go.

[KronusOfChaos]

Throw idea's away...lol.. I am at a loss myself. I did try that along with cleaning connector's as well as card itself. I've even reflowed the '040 processor area. I haven't tried doing much to the PPC area or other chips. I am trying to boot to os 3.1, but never get that far. Can't get to PPC config menu via ESC nor the early boot menu.

[Toni Wilen]

One possible reason is flash rom corruption.

BPPC has diag boot rom ($f00000) which gets executed very early by KS ROM. Logica ROM won't call any boot ROMs.

Another (strange) test is to connect it to A500+ACA500 combo and check if ACA500 menu works and it hang/crashes after selecting KS ROM

EDIT: if it has 040 (not 060), creating custom KS ROM with diag rom check disabled may help to confirm the problem.

[KronusOfChaos]

That's a cool idea. Need to dig out my 500 plus to do. I'll give that a try. Thanks Toni and thanks everyone for your input.

Also I see the info out there on creating the custom KS ROM, but how would you disable the rom check?

[Toni Wilen]

Originally Posted by KronusOfChaos

Also I see the info out there on creating the custom KS ROM, but how would you disable the rom check?

A1200 KS3.1: Modify offset $fe, byte $67 -> $60 to disable it (and fix checksum). It may still crash if any resident module is corrupted but at least you should see some background color change or yellow screen now.