I don't know your bios maker but typically you'll pull out the ole' VISA/MC and call the manufacturer (or bios distributor) and plunk down about 25 bucks for a new one. Bios distributors you should note sometimes buy bulk stock and like some OEM chips can change hands many, many times before the end user gets it.
You've got one chance! Modern BIOSes are protected, at least the the Boot Block is write protected. This means that enough of the BIOS should have remained intact to let you boot the system from a floppy. The problem is that PCI and AGP are not supported so unless you happen to have a motherboard with an ISA slot and have an ISA video card you won't have any video. Fortunately this won't prevent you from fixing your problem by reflashing the BIOS.
You will need a bootable floppy disk, containing the flash program, a good copy of your motherboard's BIOS, and an AUTOEXEC.BAT file which will contain instructions to perform a BIOS flash in unattended mode.
Follow the link below. You will find detail instructions on how to recover your BIOS (with or without video).