Your P2B-LS uses a HIP6004ACB which as you expected, does not work with Coppermine voltages. It will only go down to 1.80V. If a CPU asks for less than that it will shut off the output (0V) instead.

Your P3B-F has a HIP 6020ACB which is a lot newer (mid 1999 date code). According to it's datasheet it supports all VIDs down to 1.30V. So that board just needs a BIOS update and it should work happily with Coppermines.

shamino wrote on 2022-02-22, 22:55:

Back when they were easier to get, I bought a Celeron 1100 to stress test 440BX boards that I was selling, but I can't remember if I ever did that on the P2B. I think it would be fine though.

It works fine on a P2B-S rev. 1.03 with BIOS 1014s.003 here:

Thanks!

Well, that makes things both easier and more difficult. If I give up using my beloved P2B-LS and switch to the P3B-F… I could use a Coppermine CPU and not worry about the LS’s oversized board size and fitting it into a new case.

I’d lose my completely unnecessary SCSI system, but I’m only using that for a DVD drive anyways. Although I’d wanted to put my old SCSI 12Plex in the system (used highly inconvenient CD caddies). But… I do have a Tekram DC390-F PCI SCSI card that I’d used back then, if I wanted to torture myself.

I’d also lose the P2B-LS’s built-in LAN, but the P3B-F box already held whatever random PCI network card I’d been using on that system.

The big problem seems to come with Coppermine CPUs: the faster 100mhz FSB Slot 1 models seem very difficult to find at a reasonable price.

1100? Nope. 1000? Nada. 850? Zilch. Not even 800 or 750.

I can find 700/100 okay, or 1000/133. If I went for the latter I assume I could just run it at 100 and turn it into a 750mhz?

You'll have to flash the bios if its not already running the lastest version.

Sunflux wrote on 2022-02-23, 17:39:

If I went for the latter I assume I could just run it at 100 and turn it into a 750mhz?

I'm doing that but I run it at 7.5 x 112.