From: Lowey@Sask.USask.CA (Kevin Lowey
Subject: Trident 8900C 800x600x16 and DOS problems
Originator: lowey@jester.usask.ca
Reply-To: lowey@jester.usask.ca
Organization: University of Saskatchewan
Date: Sat, 26 Sep 1992 18:58:59 GMT

Hi,

I have an 80486-33 with a 1Meg Trident 8900c video card, and a
non-interlace video monitor.

Since OS/2 2.0 came out, I have had no problem running the Trident
800x600x16 seamless mode DISPLAY.DLL. I could switch back and forth
between DOS, OS/2, Windows-FS, and seamless windows sessions just fine.

Recently, I realized that the jumpers on my card were set incorrectly
for noninterlace mode.  I changed the jumper to allow noninterlace
operation with my monitor.  Again, everything worked fine in this
mode. (The 256 colour modes sped up significantly when I did this.)

I've tried the other modes, such as the 256 colour modes, and the
1024x768x16 colour mode.  These worked fine, EXCEPT that when I switch
back to a running DOS session from the WPS, I end up with garbage on
the screen.  Things like flashing blue and yellow boxes instead of
text.  If I was at the DOS prompt when this happened, I could type
MODE CO80 to get the "correct" mode back again, but if I was in a
running program, I couldn't do anything to fix it.  I decided to go
back to the 16-colour 800x600 mode, and everything worked fine.

After this, I started experimenting with the Trident DOS utilities
disk to see if I could configure the Trident card to work correctly
when switching back to DOS sessions.  I ran the TRIDBIOS utilitiy to
install the extended Trident BIOS. (I don't think that's the right
name, I'm not at home right now.  There are two files, one .SYS file
that is a device driver, and a .COM file that installs the extended
BIOS as a TSR).

This didn't help with the DOS problems I was having in the other
modes, so I set everything back to the 800x600x16 mode again, with the
proper SVGA ON settings, etc.

My problem is this.  Ever since I ran the TRIDBIOS program, I now have
problems with the 800x600x16 mode, which used to work fine before.
When I switch back into an already running DOS session, instead of
coming back in the correct 80x25 video mode, I end up with six
"screens", three on the top, three on the bottom, partially
overlapping each other and flickering.  Again, at the DOS prompt, I
can type MODE CO80 to correct the problem.  However, if I'm already in
a program, I can't do anything to fix it.

I've tried everything I can think of to get the 800x600x16 mode
working correctly again.  I even went so far as to re-install the
standard VGA system, do the SVGA ON from there, then re-install the
800x600x16 drivers (Both the latest one from FTP-OS2, and some older
ones I have from an archive called TRIDOS220.ZOO) again.  All with no
luck.

It almost seems to me that the TRIDBIOS program changed something in
some Non-Volitile Ram on the Trident card.  That's the only
explanation I can think of, as I've reset everything back to where it
was before I had this problem but the problem persists.

Does anyone have any suggestions on:

1) How do I get my 800x600x16 seamless drivers to work again.

2) How can I get the DOS sessions to work correctly in the other
   modes, so I can switch between OS/2 and DOS sessions without messing
   up my DOS screens in the 256 colour modes, or 1024x768x16 colour mode?

Thanks,
- Kevin Lowey


-- 
- Kevin Lowey (Lowey@Sask.USask.CA)
>>>>> Anonymous FTP to FTP.USASK.CA for DOS, OS/2, and Windows programs <<<<<

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