This bios is untried as I was looking for Rev A1 bios patch and just found a bunch of these lying around on a Japanese site.
The following files are found inside the driver download file.
|BXAD_D4.BIN||262.1 KB||8 May 2000|
|AWDFLASH.EXE||23.1 KB||6 Jul 1998|
|Update BIOS Procedure.doc||48.1 KB||20 May 1999|