Date: Mon, 23 Mar 1998 19:13:21 -0800 (PST)
Message-Id: <199803240313.TAA27296@adit.ap.net>
Mime-Version: 1.0
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To: Shawn Hargreaves <ShawnH AT Probe DOT co DOT uk>, djgpp AT delorie DOT com
From: Nate Eldredge <eldredge AT ap DOT net>
Subject: Re: Resolve a bet : Simple hello world sample at 640x480?
Precedence: bulk

At 10:34  3/23/1998 -0000, Shawn Hargreaves wrote:
>Nate Eldredge:
>> There's nothing magic about Allegro.
>
>No, of course not :-) But in this case you have slightly 
>oversimplified your code, to the point that it will only
>work correctly on some machines!

Okay, I figured it was simplistic. Ah well, what does anyone expect from a
five-minute hack based on the Interrupt List? :))

>VESA doesn't require the BIOS character output functions to be 
>supported in SVGA modes, and this call will fail on a significant
>number of machines.

AFAIK, mode 12h is not VESA. The Interrupt List called it "VGA". But I'm
quite liable to be wrong.

> This can be determined by checking bit 2 of
>the ModeAttributes flag, but that means you have to examine the
>mode information structure (using a conventional memory buffer),
>and then have some alternative method for drawing the message
>(which means providing a font of your own, or routines to get
>a copy of the BIOS one).
>
>Of course this is all perfectly doable, but it requires quite
>a bit of code to make it work correctly. My understanding from 
>the original post was that the bet is whether this can be done
>just a screen or so of code, and for that I think the answer
>must be no...

Well, it depends on how picky you want to be. It can be done on *my*
machine!! :)

Nate Eldredge
eldredge AT ap DOT net