Sharedoc,
In regard to the possibilities you mentioned:
1) I'm sure it's not related to CPU temperature - I'm doing all this with the system partly disassembled and can check the heatsink by touch, and it's not abnormally hot at all.
2) Yes, I'm pretty sure it is, as you suggest, "... some Win98SE drivers or initialization files that cause the problem ...". The question is how to identify them!
As regards Linux. I had not ever tried it, but found and downloaded a version called Puppy Linux v2.12 which runs from a CD. It was only a 70MB download for the ISO image; I burned a CD and gave it a try. It did boot up on the system with the FSB modified to 100MHz and the P-III installed, but it took a
very long time to complete the boot - almost 4 1/2 minutes! When I switched to the P-II/300, (450MHz with the 100MHz FSB), with the same CD the boot completed in a little under 2 minutes! What I was timing was the entire process from the disappearance of the IBM ThinkPad logo screen to the appearance of the Linux GUI desktop and intro screen; this required responses to some prompts about testing the video card but I think any delays would have been similar for both trials. I'm not at all familiar with Linux so didn't do much more than just test if it would boot, although I did note that the floppy drive worked OK with the P-II, but didn't work with the P-III. So the P-III system booted, but it seems something's not right!
I've been trying a few other things hoping to get Win 98SE to boot properly with the P-III, but still without success.
I also installed the P-III/500 in an unmodified 390E system (66MHz FSB) with the correct '390E' BIOS. The BIOS says it's a "Pentium Pro/333MHz", which is consistent with it reporting "Pentium Pro/500MHz" in the modified, 100MHz FSB, system. And guess what - the boot hangs at exactly the same point! So it seems the problem's not related to the 100MHz FSB mod as I had thought! My experiences suggest that one cannot simply swap the CPU from a P-II to a P-III in a 390E! It may still be possible to get the P-III system to run Win 98SE, but it's looking more and more like it's necessary to re-install the OS! I did have some success when I did that before except that I had only 640x480 video, and after I installed the proper Neomagic video driver nothing worked any more!
I've compared the BOOTLOG.TXT file from a successful boot with the P-II/300, to that from an unsuccessful boot with the P-III/500. The files are identical up to the point where the P-III boot attempt hangs, and the next entry in the P-II bootlog file is "SYSCRITINIT = VMM". A Google search on that produced quite a few hits, but mostly they were just in listings of "BOOTLOG.TXT" files. However I did find a page titled "Description of the Windows 95 Startup Process" at
http://support.microsoft.com/kb/174018 with the information:
"SYS_CRITICAL_INIT (SYSCRITINIT):
Interrupts are disabled during this phase. This gives VxDs time to prepare for device initialization without being interrupted by the system. No file I/O is allowed during SYSCRITINIT, so all SYSCRITINITs are not written to the Bootlog.txt file until after SYSCRITINIT is complete for all VxDs."
This seems to explain why the log of the failed boot process gives no information of exactly what failed - not very helpful! The file from the successful boot with the P-II shows what's supposed to be happening - a bunch of 'vxd' files are being loaded - but there's no way to know which one is causing the problem with the P-III. After more Google searching I learned that the 'vxd' files required by a particular system are set up in a file called "C:\Windows\System\vmm32.vxd" at the time of installing the OS, and that if additional 'vxd' files are later required by added hardware they are accessed at boot time from the folder "C:\Windows\System\Vmm32", where typically they have been put during the hardware installation. So I placed
ALL of the 'vxd' files extracted from the Win 98SE CD into that folder, (and also replaced the existing "vmm32.vxd" with the 'virgin' one from the CD which was the recommended procedure I had found for fixing 'vxd' problems!), thinking that that should allow whatever file(s) that might have been missing to be loaded.
BUT, THAT MADE NO DIFFERENCE WHATEVER!
At this point the only idea I have left is to once again try a clean install of the OS. If anyone reading this has other suggestions I'd be very interested to hear them.
I don't recall reading any posts in this thread about the 600E having problems when a P-II was swapped to a P-III, apart from the L2 cache not being recognized properly, and a fix was developed for that. The 390E doesn't seem to have any problem recognizing the P-III, L2 cache included, at the BIOS level, it's just when booting the OS - and so far I have tried only Windows 98SE. Can anyone contribute some insights on this, or has anyone else tried putting a P-III in a 390E???