Revisited the machine last night, which was ironically the 21st birthday of the BIOS core. Its now old enough to drink. I managed to get UMBs working with the latest version of "The Last Byte". So now I got 618k free conventional memory with the machine running in real mode. No more stupid EMM386. If you have a SiS 85c411/406 EISA chipset, its the only UMB enabler that works.
I'm running into a really weird problem with the board that cropped up last night. Whenever I run Simcity 2000 (even on a clean boot), the PC Speaker starts randomly beeping and the keyboard locks up. Sometimes I get a Stack Overflow crash too. The problem also crops up when I reach the test stage of Creative's DIAGNOSE program. The problem isn't the soundcard though, as it still happens in SC2000 with the card pulled. Any items what may be causing this problem? I'm suspecting the keyboard controller for some reason.