Intel released a BIOS update for the PR440fx, version 1.00.90.DI0. However, if you try to install it on a toshiba machine (which has BIOS 1.00.01.DI08 on it), it will fail with a cryptic error.

The workaround (described here) is to set the flash jumper to the 'recovery' position, then boot off the upgrade floppy. This will cause it to 'recover' the intel bios over the toshiba one, and it works fine.

Just remember to back up the toshiba bios first, or download a copy from the link above, just in case you need to go back to it.

When you use the recovery process, the screen will be blank the whole time. It will beep once, read the disk for a minute or two, then beep twice. Once it does that, shut off the machine, reset the flash jumper, and reboot. No more toshiba logo, and you'll have the newer bios installed.

This is of course unsupported by toshiba or intel, but then, so is just about everything about these old machines at this point.