Carrera SE30 control and Bolle Carrera040 in the Mac SE/30

Note that issue only occurred on the reloaded board - if you don't have a reloaded board with a socketed FPU, I wouldn't suggest desoldering it. Instead I would try installing the stock ROM rather than the aftermarket one.
 
Note that issue only occurred on the reloaded board - if you don't have a reloaded board with a socketed FPU, I wouldn't suggest desoldering it. Instead I would try installing the stock ROM rather than the aftermarket one.

This is a new one to me, is it a Carrera + HC Video 30 card + aftermarket ROM issue, or just a Carrera + aftermarket ROM issue?

EDIT: Ah, found your answer to this

Also how could it just affect the Reloaded board since it’s electrically identical to the original?
 
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This is a new one to me, is it a Carrera + HC Video 30 card + aftermarket ROM issue, or just a Carrera + aftermarket ROM issue?

EDIT: Ah, found your answer to this

Also how could it just affect the Reloaded board since it’s electrically identical to the original?
Multiple factors in play here, but the suggestion to remove the ROM is based out of most of the third party ROMs having lower drive than the original ROMs, between that and software changes it's adding additional variables to the equation. That said I'm not aware of any particular incompatibilities between those combinations of ROM and expansion cards.

The post you linked is specifically from the original 30Video cards with the passthrough slot, but it does have some relevance here. Best guess there was some odd termination/reflection issue resulting from the extended system bus and nothing on the passthrough slot. The "fix" was a mystery pulldown resistor on /DS which has been retained on all subsequent designs. Carreras drive the system bus directly off the FPGAs and as I recall @Bolle noted them to be somewhat picky about RAM also so the assumption is this issue is in the same family as that.

While the Reloaded board is identical at the schematic level the actual PCB layout differs meaning trace capacitance / length / noise characteristics will also be different. That shouldn't matter, but considering that particular issue Carrera is well into "weird voodoo stuff" territory, it seemed to help @codevonlux's setup. Removing the FPU would reduce the load on the bus slightly even if it isn't used while the 040 is in play, seemingly it was enough in that particular scenario. My socketed carrera didn't have this issue either so it appears to be just a particular edge case.

I don't think it's any issue of the reloaded board design just a quirk of the Carrera. So I don't recommend pulling FPUs off original SE/30 boards given there's no guarentee it'll do anything productive. Also, they're typically soldered and the stock ROM will have issues booting without one.
 
@zigzagjoe thanks for the detailed reply regarding this issue. I really appreciate your comments here and it very much ties in what we've already discussed.

So just to clarify the scenarios I have tested with your 30 video/lcd solution.

An original recapped LB with a drop in modern PSU replacement and an uprated ATX power cable.

Original ROM, original RAM. I have 8MB so I've tried every combination as well as using the least number of chips required to boot up.

Custom ROM and 128MB of RAM. Again I've tried using the minimum amount to boot up.

The Bolle riser has always been installed with your video card plugged in on top.

I can boot into 7.1 or 7.5. with my blueSCSI and the modded control panel installed.

Everything works fine in all the above scenarios until I plug the 040 card in. When the machine is pretty "cold" it will boot. But after about a minute of clicking around randomly the type 11 error appears. On subsequent reboots the type 11 is immediate upon reaching the desktop.

So my thinking is, it could be any of...

1. I have a faulty 040 card.
2. There is some kind of compatibly issue with the 040 card and the 30 video card.
3. Despite the various power improvements the numerous cards are still overloading the logic board. Or there is something not quite right with my ageing LB.
4. All the RAM I do have is causing the 040 card to fail for the reasons you have explained.

Bolle has given me an address in the UK I can send the 040 card to. Somebody with a IICI, so I guess I can at least rule out the 040 card being at fault.

If it's the combination of the 30 video card and the 040 card. I guess I could get hold of the little logic board you can plug into the ATX power connector and output b+w VGA through it. That way I could remove the 30 video card from the equation.... But still get some kind of video output to test the 040 card.

But if anyone has any further theories.... All most welcome.
 
Ah, sorry, it has been a moment and I forgot. The resistor I mentioned previously only applies to the original GS cards failing to handover from 030 to 040, if it's successfully booting on the 040 at all then it's a different scenario as far as I know.

However, I think I forgot to mention you can make a bypass plug for the grayscale card if you get a molex male connector and wire it like this. You plug this into the grayscale connector on the harness in place of the video card. Note this picture is from the front of the connector, so it will be flipped when viewed from the rear.

It's fine to use slightly different values for the resistor if you don't have 300 handy.

GS harness bypass.jpg
 
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