First post, by oz_pete
I have a 640x480x16 DOS application rather critical to my work. As our systems have upgraded I have had a dream run with no problems at all as we migrated over the years through: 3.11, 95, 96, NT4, Win2k, XP SP1. At XP SP2 I've stuck a hitch. Its not really a problem with the application which runs as well as ever but on exit, many of our XP SP2 machines of
1999 - 2001 vintage have about a 50-50 chance of going "black screen".
Our later hardware does not suffer from this although recovery of the original video state and data seems to a few tens of milliseconds longer compared with earlier OS versions we used to run.
Seems Windows is still running, but "in the dark". The monitor tells me that the original higher resolution signal has been restored (H and Y syncs ok), but all pixels are "pure black". Winding up the brightness allows the raster lines to be seen, but it seems like the video DACs have been disabled.
The problem is not dependent on the DOS app and can occur whenever a
command window is changed to a low res mode. ie. When a normal command window is expanded to "full screen" text mode (720 x400 i think),
using the properties menu on cmd.exe, a "black screen" on exit can occur.
My tech people here acknowledge it is a problem, probably in the XP images they distribute, but they won't put rescources into tracking it down as "who uses DOS stuff these days?" They do assure me that their tests in loading the lastest card drivers doesn't make it go away. The problem seems to afflict quite a range of 1999-2001 hardware with various video cards. None of these machines had problems last year with XP SP1.
Suggestions plese, I'm really on my own with this one and rapidly getting out of my league.
