Jasin Natael wrote on 2020-10-26, 23:07:

Using this post as a reference
mb-8500ttd manual needed

I flashed my BIOS with the linked Jan Steunebrink BIOS patch. But no matter what I do I can't seem to get my board to POST with my k6-3+ chip. The board works just fine with my Pentium 166mmx, and the K6-3+ chip works just fine in my Compaq Presario, but no matter what voltage\multiplier\ram combinations that I try it simply won't post in this board. I noticed doing some digging on the web that some boards seem to have different JP7, JP8 provisioning. Would this have something to do with it by chance? If anyone has any ideas or experience with this combo please let me know.

There could be different revisions with changes in the jumpers. Did you follow feipoa's comment on removing the TAG from cache and other things mentioned in that topic ?
The board was never designed to run a K6-3, even with BIOS support there are issues. Why not try a K6-2 333 or 350 ? Found a couple a few months ago for very reasonable. Just a thought....
added: you do not mention what speed K6-3+ you have ...

Horun wrote on 2020-10-27, 02:09:

There could be different revisions with changes in the jumpers. Did you follow feipoa's comment on removing the TAG from cache and other things mentioned in that topic ?
The board was never designed to run a K6-3, even with BIOS support there are issues. Why not try a K6-2 333 or 350 ? Found a couple a few months ago for very reasonable. Just a thought....
added: you do not mention what speed K6-3+ you have ...

It is a 450mhz. I did not remove the TAG ram. understand that it will need to be removed for stability sake, but it should still POST with it installed I would think? I can't locate my K6/2 chips, I have a few but I'm not sure where I have stashed them since moving a few years back.
I know that the board wasn't meant to run a K6-3 chip but as others have been able to get one to run, and the undocumented voltage settings exist I figured with the patch it should be possible.

The main reason that I would like to get this machine up and going is that I'm expecting my second child soon and I'm downsizing my office area to accommodate for her. I only have room to keep one retro PC.

I've got many other faster ones but I'd like to have one that is a bit more versatile for DOS all the way up to Unreal engine games. The k6-3 and my Voodoo 3 makes this much easier.

At any rate I appreciate the advice.