Recovery from a corrupted BIOS upgrade for GA-686BX

Seeking help in recovering from a corrupted BIOS upgrade for GA-686BX.

This was my first time upgrading a BIOS. I used the F1 file from the
Giga-byte web-site, as I was only interested in allowing the use of a
40Gb HDD. Now I see that I should have used the F2a BIOS.

I saved the original BIOS to a floppy. Then initiated the upgrade
which genereted the "BIOS ID error". I ESC-ed back out.

Now the PC will not complete the boot-up process. It gets past the
memory test, displays the "Award Plug and Play BIOS Extension v1.0A"
message, flashes the keyboard LEDs, then hangs.

Pressing DEL of Ctrl-Alt-Del does not start the BIOS set-up.

Tried the "pull battery" trick - no go.

Tried booting with a "bootable" floppy with the GB distributed AMI
"Flash Utility" with 6BX.F2a file and proper AUTOEXEC.BAT - no go.

Any other tricks for recovery (minus get another ROM chip)?