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Acer 710 8088
- Thread starter JT64
- Start date
Scali
Veteran Member
Since VGA is backward-compatible with CGA/EGA, the only way to use both in a single machine is if the VGA card is configured as monochrome afaik.
Otherwise the VGA card will use the same I/O addresses and memory range as CGA/EGA, and they can't work together (there are separate ranges for monochrome and colour).
Normally if you want to install a VGA card into a machine with onboard graphics, you switch the onboard graphics into MDA/Hercules (monochrome) mode if possible.
Otherwise the VGA card will use the same I/O addresses and memory range as CGA/EGA, and they can't work together (there are separate ranges for monochrome and colour).
Normally if you want to install a VGA card into a machine with onboard graphics, you switch the onboard graphics into MDA/Hercules (monochrome) mode if possible.
Last edited:
Since VGA is backward-compatible with CGA/EGA, the only way to use both in a single machine is if the VGA card is configured as monochrome afaik.
Otherwise the VGA card will use the same I/O addresses and memory range as CGA/EGA, and they can't work together (there are separate ranges for monochrome and colour).
Normally if you want to install a VGA card into a machine with onboard graphics, you switch the onboard graphics into MDA/Hercules (monochrome) mode if possible.
Does the MDA monitor also use same IRQ as the CGA, EGA, VGA i tried by flip the onboardswitch to MDA but it does not work. But you think that switch VGA card in to monochrome will? I have a paradise clone and i think i can set it to monochrome.
http://museum.ttrk.ee/th99/m/A-B/31619.htm
Thank you!
Scali
Veteran Member
Does the MDA monitor also use same IRQ as the CGA, EGA, VGA i tried by flip the onboardswitch to MDA but it does not work.
Hum, that SHOULD work. I've had multiple systems with an MDA/Hercules card and VGA side-by-side. The PC standard is designed to have monochrome and colour adapters in separate ranges, so they can work together.
Have you tried disabling the onboard video altogether? Does the VGA work then? It could be that your VGA card does not have a BIOS that is compatible with your machine.
But you think that switch VGA card in to monochrome will?
I'm not sure if it will work, but if you can't get it to work by switching the onboard graphics to monochrome, then perhaps it will work by switching the VGA to monochrome. But this is a configuration I have never tried.