90x60 text mode

[ksr]

Hi there,

I've been looking but can't find any code for changing the text mode size. I believe this requires changing some VGA registers but again I can't find much information.

Does anyone have any (real mode, asm) code to do this?

Thanks.

[Grunt]

Check out geezer's modes.c.

[AJ]

Hi,

Have a look at VGA Resources on the wiki. The last link (changing text mode font) is excellent. Although it is in PMode and is in C, you should be able to adapt it to your purposes. There also seems to be an assembly 90x60 link, but if you simply copy and paste that, you won't really understand what's going on.

For a good understanding of the VGA, read the code in the link along with register information from FreeVGA.

Cheers,
Adam

[johnsa]

The references mentioned above are a perfect place to start with direct VGA tweaking including 90x60 text mode. However you should know that 90x60 doesn't work on all machines. On 2 of my desktops it's fine, but on some dell machines i have including an optiplex and a latitude it just jams up the entire machine.
So if you're aiming for compatability I'd avoid it. Normal 80x50 mode however seems to work everywhere I've tried.