Trying to resurrect my old Pentium 120 machine from the mid 90's, my tech expertise is middling at best. Figured I'd reach out to the experts here and see if any better insights. So far have machine up and running with Windows 98, but I'm trying to flash the BIOS on my Micronics M54Hi motherboard (09-00236-02-Rev: A2) from 4.04 to 4.05 to solve the large HD issue that was present on Phoenix BIOS 4.04. I've come across an update online from what appears to be a now defunct company called Micro Firmware that sold a BIOS update called M5HS10 that would bring this MB up to Phoenix 4.05. Issue is that the file I've found multiple places online m5hs10up.exe, contains an update of this original M5HS10 BIOS, but not the original, and it won't let me update without this earlier version already in place. Looking at some old release notes I found online the original release version of M5HS10 appears to be 4.05.09, and the update I have is 4.05.21. The contents of the m5HS10up.exe file are as follows:

BCMD.CO_ 9.2 KB 7 Jan 1999
INSTALL.EXE 179.4 KB 7 Jan 1999
README.TXT 5.3 KB 5 Jan 1999
BBSYS.SY_ 512 bytes 7 Jan 1999
BBDOS.SY_ 7.4 KB 7 Jan 1999
INSTALL.INF 52 bytes 7 Jan 1999
LICENSE.TXT 2.8 KB 11 Mar 1998

Any thoughts out there on where I can find the original m5HS10 update (I've spend hours searching with no luck) or a workaround to flash the BIOS with what I have? The file I have works off what looks to be a proprietary install program so I can't do it via Phlash from what I can tell? Thanks in advance, and if I've omitted any required info please let me know.

Nick