Jim Cornette: >>> Unless you need to access the BIOS via the USB keyboard, (or old DOS, >>> win OS) legacy USB support is not needed. Tim: >> I found you couldn't operate GRUB without it, it needed a PS/2 keyboard, >> or the BIOS emulating it. Tried that on three different motherboards. Jim Cornette: > I didn't realize that grub was so limited. I guess with the space it > occupies, it is pretty much legacy. Thanks for the information. > > Does it hang at grub or does it proceed to boot after the timeout? It just boots in the default manner, with no way for you to make any changes. That's not a problem if you don't need to change anything, but you'd have to reboot (using something other than the keyboard) and do something else (change BIOS options / plug in a PS/2 keyboard) if you needed to change GRUB options.
