These are PCI Power Macs, they do not have NuBus slots (and a Radius Rocket would be comically underpowered compared even to the stock single CPU 604 and 604e cards these machines shipped with).
Per the ANS 500 developers' guide, ROM should be addressable in that range. I don't know if the full firmware-assisted AIX sysdump will include it, though.
Should be possible to dump ROM from OF in any case:
0 > 100000 0 do ffc00000 i 4 * + dup 3f and 0= if dup cr 8 u.r ." :" then @ 8 u.r...
Could the ROM map be extracted from a complete dump, as triggered by AIX sysdumpstart ?
https://aix4admins.blogspot.com/2011/06/aix-generates-system-dump-when-severe.html
Here's a photo of my friend's ANS ROM. These are the only identifying marks.
He would be up for dumping the ROM if someone can come up with the AIX command(s) to do so.
I've reached out to a friend who has an ANS, and he'll get me the ROM part number.
I've also checked the 1066-page Module Identification Guide (and the European supplement) and it suggests that the ROM SIMM for the ANS 500/700 was not offered as a separate line item. Instead, the ROM SIMM was...
I haven't found any standalone G3 or G4 cards in that range (other than the Sonnet cards that don't work in the late PT Pro) that are affordable on my hobby budget. I have a couple of 400 MHz ZIF G3s and a 500 MHz ZIF G4. So those would seem to make sense. If they worked.
I do have other...
So, I installed a pin header at what would be Vpower for the missing regulator (confirmed it has continuity to the power pad on the CPU socket) and one of the ground plane test points, and I'm getting pretty clean 3.3V to the card.
Hmmm.
Interesting that Interex didn't populate the space they left for a voltage regulator...
I may solder on a header to Vpower here and see what the card is really getting.
I just checked the power supply again, all the rails seem good. 12V is reading a bit high (12.6) when under load, but that's within modern spec for ATX.
I was thinking about that voltage regulator thing as well. It seems to be the biggest difference between the cards.
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