From: Ian <dr838303 AT cs DOT nthu DOT edu DOT tw>
Newsgroups: comp.os.msdos.djgpp
Subject: Re: Allegro and S3 trio64*
Date: 22 Sep 1998 15:46:44 GMT
Organization: Dept. of Computer Science, Nat'l Tsing Hua Univ., Taiwan, R.O.C.
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References: <000101bde63b$7fef73a0$6d4d08c3 AT arthur>
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Arthur  <arfa AT clara DOT net> wrote:
:> Hello everyone,
:>
:> How great the Allegro! It's so cool. However, I can't run all example
:> programs successfully on my machine. The programs setting the video mode
:> by the function set_gfx_mode(GFX_AUTODETECT,.... ) all failed. I then
:> test these programs on another machine with an S3 trio64v2 (mine
:> is trio64+).
:> Now all programs can successfully execute, but occasionally they
:> end abnormally.
:> Isn't the trio64* family fully supported by Allegro?

: The S3 Trio family is not the most compatible of graphics cards, and drivers
: tend to be rather buggy. I'm not sure if there is a bug fix for Allegro, but
: I don't believe it's Allegro's fault since it uses Mode 13h, ModeX or Vesa
: 1.x/2.0 for the most part (which are standardised). It could be that you
: havn't got the latest drivers for your card, so download them or get SciTech
: Display Doctor.

: You could always change the GFX_AUTODETECT to GFX_VESA2L or other modes to
: see if they work, then you can work out which modes cause the problem.

: James Arthur
: jaa AT arfa DOT clara DOT net
: ICQ#15054819

I decided to trace the demo.c file since it can run smoothly on my trio64v+
even when I select GFX_S3 1024*768. In my little test program I've tried
GFX_S3, VESA2L, AUTODECECT, MODEX, etc, all failed, only the GFX_VGA suceeded.
I've also tried to copy the example programs, and modify the GFX_AUTODETECT
to GFX_S3, GFX_MODEX, then recompile it. That still doesn't work. So when I
saw the smooth animation of the demo I was so suprised. Even I intended to make
this demo program down by selecting S3, MODEX......, It didn't mind. I guess
there must be something different in handling video modes in demo and example
programs.