Sorry for the very simple (perhaps stupid) questions/suggestions:
1) Did you set the jumpers on the slocket correctly? (If you look on the slocket, the instructions for the settings should be printed.)
2) Did you set the correct CPU power settings in the BIOS?
..Sorry again if I'm giving you obvious suggestions for things you may have already done.

If the jumpers are same as the photo You have provided, then JP1 is set for Celeron, not Coppermine.

igna78 wrote on 2026-08-26, 00:16:

Sorry for the very simple (perhaps stupid) questions/suggestions: 1) Did you set the jumpers on the slocket correctly? (If you l […]
Show full quote

Sorry for the very simple (perhaps stupid) questions/suggestions:
1) Did you set the jumpers on the slocket correctly? (If you look on the slocket, the instructions for the settings should be printed.)
2) Did you set the correct CPU power settings in the BIOS?
..Sorry again if I'm giving you obvious suggestions for things you may have already done.

It's fine to go over the basics, all of us forget them at times. Hell, I forget the power cable often times!
Yeah, I went through all of the jumper settings possible on both the slotket and motherboard. The latter has been set up for 133MHz FSB, with no option to change vcore. There are jumpers for changing the clock ratio, though..

Imperious wrote on 2026-08-26, 00:25:

If the jumpers are same as the photo You have provided, then JP1 is set for Celeron, not Coppermine.

I have the jumpers on there set for Coppermine, and have tried the "overclock" jumper on and off to no avail. All other jumpers mess with dual CPUs or Intel/Cyrix.

According to The RetroWeb, your motherboard should fully support Coppermine CPUs :
https://theretroweb.com/motherboards/s/tekram-p6bx-a

That said, the next steps I would try are:
1) Update the BIOS to the latest version available (if not already done) and try again.
2) Try again using another slotket known for its compatibility with Coppermine CPUs (Abit Slotket III or MSI 6905 ver. 2.3).

From personal experience, I can tell you that sometimes even with a slotket known for its compatibility like MSI 6905 ver. 2.3 on some motherboards I had problems then solved with a slotket of another brand (Abit or QDI)

BIOS update was my next attempt, and the latest one ended up corrupting the BIOS. No big deal as I had an EEPROM programmer, but it still did not help things. I'm thinking that while this revision supports 133MHz FSB natively, it does not actually support the Coppermine core, and that would be under the later revisions. Might try this again later if I find something like the MS-6905 v2.3.

On another note.. Is a 1GHz Pentium III even a good idea for a Windows 98 system in the first place? I want a semi-permanent duo setup of a '90s PC and '00s PC next to each other, side-by-side on a desk set up like an old LAN party. The '00s PC already handles that whole decade with ease, as well as some late '90s titles. I'm thinking maybe the 1GHz P3 is maybe not the right call? I just knew it was a pretty decent fit for a Voodoo3 2000. Perhaps I should look more into the lower clocked P3s or even higher clocked P2s. I also have a 5x86 system somewhere I could mess around with, but then again, that would only accommodate for PCI graphics, to which I'd be limited to an S3 Trio of some kind, or a PCI TNT2 M64 or Matrox G200.

I have a Tekram P6BX-An (Rev. 1.02) running a Tualatin 1400-S on a MS-6905 Master slotket. And before that it run Coppermines on same slotket. This board can handle all of that OK.

(^ For some reason AIDA thinks the mobo is a "ENPC EP-KB23", but it's in fact a Tekram P6BX-An)

altarofmelektaus wrote on 2026-08-25, 23:52:

... It's got some weird issues with the POST memory check cycling three times or so, was missing half the capacity of some PC100 modules entirely, hates one of my PCI NICs and has dodgy brand capacitors ...

^ I suspect your Tekram P6BX-An might be in need of a recap. The OEM lytic caps were bottom of the barrel junk, not to be trusted at all after ~25 years.

Old Mobo Recap: 440BX Tekram P6BX-An