henrybankshaft wrote on 2025-05-31, 00:47:

Recently got the bug to go back in time and build a Windows 98 gaming rig. I have an AOpen AX3SU motherboard. I also had a 1.4GHz Tualatin Pentium III laying around. The manual for AOpen says it supports Tualatin 1.2GHz+ - but not specifically 1.4GHz. wondering if there is incompatibility here.

The PC is able to turn on, but the Bios boot screen shows a "Tualatin DP Not Supported" error. Anyone with more knowledge/background have input? Searching the error didn't turn up much usefulness so wanted to turn somewhere else where someone might know more about it. The PC then shuts off without allowing entry into any bios settings.

I tried replacing the CPU with a P3 866 I had laying around but it doesn't even get to the boot screen. Not sure if an issue with the processor or not, but that's a different problem 😀

See this link re the v1.06 BIOS... https://web.archive.org/web/20040825152839/ht … ge=Trad+Chinese

Needs an update... https://theretroweb.com/motherboards/s/aopen-ax3s-u#bios

But don't try updating the BIOS with the unsupported processor ...

IF you can disable the cache, and just to be safe, underclock it to 66/100fsb, there's no architectural difference between 1.2 and 1.4, so it should work for a flash.

Should.

Your risk.

I have an Intel board that does the same thing, it will run any of the tualatins with the 256k cache but will not run any of the tualatins with 512k (-s) processors.

For my board I suspect its just intel's bios way of restricting of running the server version of the tualatins.

There were two variations of Pentium III Tualatin microprocessors. Desktop version of Pentium III Tualatin CPUs had 256 KB L2 cache. Server-class processors had 512 KB L2 cache and were branded as "Pentium III-S". The difference between desktop and server Tualatin microprocessors was not only in L2 cache size. Desktop processors didn't support dual-processing, and only Pentium III-S CPUs could work in dual-processor systems.