The placement of the connector is quite self-explanatory: +3.3v for PCI.

Now voltage modules are interesting, because they are tied to arrival of Socket 7, which initially was only optionally compatible with split-rail CPUs.

I have such a motherboard, but without video. It has been running P-MMX 233 for many years without an additional VRM. To set the multiplier to 3.5, a wire jumper is used on the processor pins. This board also has a working PS/2 port, you just need to solder the mouse header and FB8N1, FB8N2, FB8N3. I used jumper wires.

Shouldn't multiplier just be set to 1.5 and the p55 interprets it as 3.5?

Im skeptical about this being a footprint for a dual voltage regulator. Those need a way of being wired between CPU and power source, that means jumper links when one is not fitted. No jumper link means CPU is hard wired to 5V.
btw where is the ram for mach64? does it come with a daughterboard out of the box?

rasz_pl wrote on 2024-01-20, 13:34:

Im skeptical about this being a footprint for a dual voltage regulator. Those need a way of being wired between CPU and power source, that means jumper links when one is not fitted. No jumper link means CPU is hard wired to 5V.
btw where is the ram for mach64? does it come with a daughterboard out of the box?

This is actually a generic photo from the internet that I lazily edited to make it look a little more similar. I was too lazy to disassemble it from the horizontal case to take a photo. It has 1mb onboard, and accepts upgrades to up to 2mb via sockets.

Darmok wrote on 2024-01-20, 05:56:

I have such a motherboard, but without video. It has been running P-MMX 233 for many years without an additional VRM. To set the multiplier to 3.5, a wire jumper is used on the processor pins. This board also has a working PS/2 port, you just need to solder the mouse header and FB8N1, FB8N2, FB8N3. I used jumper wires.

Thanks for the information, this is of great help. I saw a manual that had a variant with PS/2 ports, and even a variant (from Dell) with S3 graphics and onboard sound vibra, but I never found anything about P55 in it.

I remember that about 20 years ago, when I was younger and inexperienced, I had a computer with exactly this same board, I simply put on a K6-2 and turned on the computer, immediately smoke started coming out of somewhere, I quickly turned it off, and I went back to 133mhz, but it never became slower than before. 🤣