Hi. I have a Compaq Portable II computer (1986, 286 luggable PC) and I
recently installed a 1.44MB floppy drive. The Bios ROM chip that is in the
unit only supports up to 1.2 5.25" floppies. I did some research and for me
to be able to use a 1.44MB 3.5" floppy I need BIOS ROM revision .N3 or
later.

Holy crap :-}

Err, about the only thing I think I could possibly suggest would be any
of the online computer museums - you might just touch lucky !