Note: I'm not responsible for any damage this method may do to you or your computer !
1. Replace the corrupt chip by a working one. The best option is to take the working BIOS chip from a motherboard which has the same chipset although that's not absolutely necessary. It just has to give you a chance of booting into DOS. Before pulling the working BIOS chip out of it's original motherboard, set the System BIOS cacheable option in the BIOS to enabled.
2. After you have put the working BIOS in the motherboard with the corrupt BIOS boot the system to DOS (with a floppy or HD).
3. Now replace (while the computer is powered on) the working BIOS chip with the corrupt one.
4. Flash an appropriate BIOS to the corrupt BIOS and reboot.
Ovo gore ili nać nekog ili neku firmu sa programatorom pa da stavi bios direktno na bios chip