Last year I bought a bunch of LM2636 VRM controller ICs with the idea that I could upgrade 440BX boards that should normally be Coppermine compatible if not for their outdated VRM controller.

I have in front of me now an FIC VB-601 v1.4 with the latest BIOS installed from 11-2000 and it will not POST with a Coppermine installed (other CPUs work fine). In my experience, BIOS support for Coppermine is rarely an issue as long as the CPU is calling for a voltage that the VRM controller understands. The RC5053M is very likely the culprit since the datasheet says it only supports 1.8v-3.5v, where as Coppermine compatible controllers will normally say 1.3v-3.5v. So, I think this is a great candidate for a controller swap... if it's compatible!

Looking at the datasheets for both controllers, it seems like the pinouts are basically the same though the terminology is different between the two so I can't say 100% for sure.

Could someone with a bit better understanding of these things take a look at these two datasheets and let me know if this is likely to work or if it would just let all the smoke out of the motherboard? If there is something in particular that determines if a swap like this viable, I would love to learn about that, so use as much detail as is necessary.

Datasheets are attached to this post, just in case they disappear from the internet.