aux/vga

aux/vga

[Berry]

>>>Boyd Roberts said:
 > 
 > Then I run aux/vga -l and the weirdest thing happens:  I get two half
 > screens, side by side, which are identical; the mouse tracks in both
 > and 8 1/2 runs fine.  I think I'm close at this stage, but I'm at a
 > loss to understand what's happening (the only thing I know about PC
 > hardware is that diskette rhymes with whiskette).  Any clues?

This sounds like a bug I had when I was doing a port of the X11R4 server to 
MS-DOS (for my sins, don't ask) about 4 years ago.  Time has muddied the details,
and my jerk boss would insist they were proprietary anyway (he's not my boss anymore,
thank God) but I seem to remember that it had to do with the VGA board 
being in 4-bit deep mode (16 colors) when the program thought it was in 8-bit
deep mode (256 colors) or maybe vice versa.  

I recently had a similar occurence on a Linux laptop, where Mosaic was too
stupid to understand about Visuals other than 8-bit deep and 1-bit deep.

Shit.  What a mess.  I can't wait for my plan9 CDROM to arrive....

  --berry

(P.S. I realize I probably haven't specifically helped Boyd, and have 
whined a lot, but I hope I have pointed him at the right place to look)

Berry Kercheval :: Xerox Palo Alto Research Center

aux/vga

[Boyd]

oops, a typo:  I have an att20c490-80.

I tried out another s3 pc and that just worked fine with the standard
setup.  It's this digital lpv+ 433sx I have that has the problem.

A minor point: aux/vga's usage message includes an f option, which it
doesn't support.

aux/vga

[jmk]

the S3 chip (which one is it?) thinks it can do 2x8-bit pixels at a time
at the higher resolutions, but it sounds like it's a standard 8-bit dac and it can't
do that (the dac you gave looks like a typo), so you see the image twice.
the highest clock you can use is 80MHz in this case.

still, it shouldn't be allowed to happen, but the insides of aux/vga are a twisty
mess. more information please.

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From:	Boyd Roberts <boyd@plan9.cs.su.oz.au>
Date:	Tue, 1 Aug 1995 19:19:14 -0400
To:	9fans@cse.psu.edu
Subject: aux/vga
Message-ID: <199508020919.5148.9.babig@plan9.cs.su.oz.au>
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Reply-To: 9fans@cse.psu.edu

I have a problem with aux/vga and my Quadtel S3 video board.  The standard
/lib/vgadb entry wasn't working so I looked at the board and saw it had a
att20c40-80 chip in in so I changed the ramdac entry, and then reordered
link=3clock ... so it was before the ramdac entry (don't ask me how I
worked this out :-) and changed the clock field to be icd2061a.

Then I run aux/vga -l and the weirdest thing happens:  I get two half
screens, side by side, which are identical; the mouse tracks in both
and 8 1/2 runs fine.  I think I'm close at this stage, but I'm at a
loss to understand what's happening (the only thing I know about PC
hardware is that diskette rhymes with whiskette).  Any clues?

The aux/vga and /lib/vgadb I have come from the pre-release that we have here.

aux/vga

[Boyd]

I have a problem with aux/vga and my Quadtel S3 video board.  The standard
/lib/vgadb entry wasn't working so I looked at the board and saw it had a
att20c40-80 chip in in so I changed the ramdac entry, and then reordered
link=3clock ... so it was before the ramdac entry (don't ask me how I
worked this out :-) and changed the clock field to be icd2061a.

Then I run aux/vga -l and the weirdest thing happens:  I get two half
screens, side by side, which are identical; the mouse tracks in both
and 8 1/2 runs fine.  I think I'm close at this stage, but I'm at a
loss to understand what's happening (the only thing I know about PC
hardware is that diskette rhymes with whiskette).  Any clues?

The aux/vga and /lib/vgadb I have come from the pre-release that we have here.