🚀 go-pugleaf

In article <1992Nov21.195314.21119W@skylark.edb.tih.no> thomash@edb.tih.no writes:
>!
>
>I've heard there is a standard MCGA 320x400x256 mode available on all VGA cards. Is this
>true, and if so -
>
>1) What mode-number is it? 
>2) How is the screen organized (bitmap/bitplanes)?
>3) Where must I write to change which bitplane/screen area to write to/read from?
>
>Thanks a lot -
>
>Thomas Hagen
>thomash@edb.tih.no

  Well... it's not exactly a standard mode.  For that matter, it's not a
mode at all - it's just a tweaked set of video parameters.  For that reason,
there isn't a mode number for it.  The screen is organized into... well...
byteplanes, I guess.  One byte corresponds to four pixels - the pixel number
(or numbers - more than one can be selected) is selected through a register.
This sounds confusing - a much better explanation than I'm capable of went
by a few posts ago.
  I'd suggest you pick up xlib04.zip off wuarchive.wustl.edu in 
pub/MSDOS_UPLOADS.  It's a great library of routines for tweaked VGA modes.

...by the way, there is one annoying "feature" of some tweaked modes - they
confuse monitors.  Sometimes they'll click and hum for a moment, or lose
the hold on the picture so you need to turn them off and on again.  Also,
in some tweaked modes (including 320x400) the picture is not the full
vertical height of the screen, so it needs to be adjusted.  Kind of
annoying, but it works.


								--Kludge