R200 flash utility
R100 flash utility
Radeon BIOS Editor

Radeon BIOS Flashing Utilities

Usage:
flashrom (R100) and for (R200) get them from links above

Get help:
flashrom /?

Get bios info:
flashrom -i

Backup (read) current bios into bios image file
flashrom -s 0 bios_nm.rom

Flash (write) bios image into card bios:
flashrom -p 0 bios_nm.rom

Try this ON YOUR OWN RISK and from PURE DOS SESSION ONLY (boot from diskette for exmaple) without himem.sys loaded (or from hard drive in step-by step confirmation mode).