18 Dec
2007
18 Dec
'07
9:06 p.m.
Dave Dunfield wrote:
Not likely - as far as I know there are no standard PC
text
video modes that give 132 columns.
VESA supports querying card capabilities (including extended text modes)
and also setting such modes through the BIOS, no bit-banging required.
Most cards made after 1996 have VESA BIOS built-in; for cards made
1993-1996, the old Scitech Display Doctor TSR should work fine.
For cards made before 1993, the card manufacturers usually provided a
small TSR that provided VESA 1.0 or 1.2 (should still have a few
extended text modes in there). The earliest VESA TSR I'd ever seen is
one from 1989 for Paradise chipsets. YMMV.
I've not done a bit-mapped version (that would be
a lot of
changes to my emulator).
I would highly recommend staying away from manual rasterization; if a
card can do 1024x768, it can do 132x25 or 132x50.
Another thing I've added in this most recent
version is that I
came up with technique when using a VGA card to not only load
a custom font which gives you all the VT-100 graphic characters,
but also to enable all of the VT-100 attributes (Bold, Underline,
Blink and Reverse) in any and all combinations.
Ah, so you are using VGA's capability to store multiple fonts and
bank-switch between them? Or something more hideous, like changing the
font every 16 scanlines? ;-)
--
Jim Leonard (trixter at oldskool.org) http://www.oldskool.org/
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A child borne of the home computer wars: http://trixter.wordpress.com/