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monotech / NuXT

MicroATX Turbo XT Motherboard, with VGA, Floppy, CF, Serial
GNU General Public License v3.0
100 stars 12 forks source link

CGA 40x25 mode #3

Closed eltair closed 5 years ago

eltair commented 5 years ago

I have an official IBM CGA card and would like the system to boot in 40 column mode, but the switch for that doesn't seem to work. The machine always boots in 80 column mode. I can switch to 40 columns successfully from dos using the mode 40 command. Any ideas? Thank you.

eltair commented 5 years ago

FYI, I'm no longer using the CGA card with this board, although I'm still curious what the switches for video card type actually do. They don't seem to have any effect on my system.

skiselev commented 5 years ago

It's a bug.... The BIOS was initially written for Xi 8088, which has only one switch (monochrome/color). And so it ignores the 40x25 mode. I've created an issue for the BIOS: https://github.com/skiselev/8088_bios/issues/3

skiselev commented 5 years ago

I've committed the fix for this issue to the BIOS repository. It will be available in the next BIOS release: https://github.com/skiselev/8088_bios/commit/d95b9110b5713eecce2dcd4c15e561234f214daa

skiselev commented 5 years ago

The fix is released in v0.9.7 https://github.com/skiselev/8088_bios/commit/08c673eb063bd22bcfc3bcb5bacfad20ed8876e8

eltair commented 5 years ago

@skiselev Thanks for fixing this! I tested it and it works, although I have another issue with CGA booting that I will submit separately.