28 Feb
2013
28 Feb
'13
12:59 a.m.
TeoZ wrote:
original IBM 5150 early model
When I try a VGA 8 bit card (or my Everex EGA set to CGA) I don't get a screen and it
doesn't boot from the floppy
The earliest PC BIOS didn't look for extension ROMs, so it can't deal
with any displays that aren't 100% hardware compatible with CGA or MDA.
Almost all VGA cards need some initialization before they can work in
CGA or MDA mode, and that's done by the BIOS extension ROM on the card.
Eric