ID Number: Q40573
5.x 6.00 6.00a 6.00ax 7.00
MS-DOS
Summary:
SYMPTOMS
When running programs such as GRDEMO that call the graphics
function _setvideomode(), a border may be displayed around the
monitor. Also, the functions _remappalette() and _remapallpalette()
do not seem to work correctly.
CAUSE
Some VGA display adapters have analog- and digital-output
capabilities. The above behavior occurs when the digital output of
a VGA display adapter is connected to the monitor.
When the digital output is connected to an ECD (EGA monitor), a
green border is displayed. When the digital output is connected to a
multisync class monitor, a gray border is displayed. In either case,
remapping the palette does not function. When the analog output is
connected to a multisync or VGA monitor, it displays correctly.
The problem is that the graphics adapter is rightfully determined
to be VGA class, although for practical purposes it is really EGA
class. At this point, the C graphics library treats the display
incorrectly as VGA. Connecting a digital monitor to the digital
output of a VGA adapter is a nonstandard hardware configuration
(the digital output of a VGA graphics adapter is nonstandard). The
behavior of a nonstandard hardware configuration is unpredictable.
Additional reference words: 5.00 5.10 6.00 6.00a 6.00ax 7.00