Thought I would add this from MicronPC website April 2001 via Wayback machine.
M55Hi Rev A Motherboards
M55HI_04.EXE 120KB (09-06-96): Rev 04 Flash BIOS for Micronics M55Hi motherboard.
Use only with Rev A motherboards.
55HI_03.EXE 122KB (06-25-96): Rev 03 BIOS flash for Micronics M55Hi motherboard.
Fixes IRQ allocations on the PCI BUS. Use only with Rev A. motherboards.
M55Hi Rev B Motherboards
55HI2M10B.EXE 138KB (07-01-97): Rev 10b BIOS flash for Micronics M55Hi motherboard,
Rev B only. This flash includes support for MMX. PER THE ABOVE INSTRUCTIONS PLEASE
CONFIRM THAT YOU HAVE A REV B MOTHERBOARD BEFORE USING THIS BIOS UPDATE.
NOTE: THIS BIOS FLASH WILL NOT WORK WITH OS/2.
55HI2M9B.EXE 117KB (12-06-96): Rev 09b BIOS flash for Micronics M55Hi motherboard,
Rev B only. This flash includes support for MMX. PER THE ABOVE INSTRUCTIONS PLEASE
CONFIRM THAT YOU HAVE A REV B MOTHERBOARD BEFORE USING THIS BIOS UPDATE.
NOTE: THIS BIOS FLASH WILL NOT WORK WITH OS/2.
M55HI2M9.EXE 117KB (11-05-96): Rev 09 BIOS flash for Micronics M55Hi motherboard.
Rev B only. THIS FLASH WILL SUPPORT OS/2 but gives no support for MMX.
M55Hi Rev D Motherboards with USB Ports
M55hi_13.EXE 183KB (12-02-97): Rev 13 BIOS flash for Micronics M55Hi motherboard,
Rev D with USB ports only. PER THE ABOVE INSTRUCTIONS PLEASE CONFIRM THAT YOU HAVE A
REV D MOTHERBOARD WITH USB PORTS BEFORE USING THIS BIOS UPDATE.
M55r6_12.EXE 295KB (07-01-97): Rev 12 BIOS flash for Micronics M55Hi motherboard,
Rev D with USB ports only. PER THE ABOVE INSTRUCTIONS PLEASE CONFIRM THAT YOU HAVE A
REV D MOTHERBOARD WITH USB PORTS BEFORE USING THIS BIOS UPDATE.
Hate posting a reply and then have to edit it because it made no sense 😁 First computer was an IBM 3270 workstation with CGA monitor. Stuff: https://archive.org/details/@horun