0112E (beta 001) is an APM BIOS.
1001E (if you can find it), is an ACPI BIOS.
Although an ACPI BIOS is better for Win2K and WinXP, an early revision such as 1001E is probably not a good idea. Early ACPI BIOSes for all ASUS boards feature COM port problems under Win2K/WinXP and have a few other minor problems.