<
hardware>
IBM and others have introduced a bewildering
plethora of graphics and text
display standards for {IBM
PCs}. The standards are mostly implemented by plugging in a
video
display board (or "
graphics adaptor") and connecting
the appropriate monitor to it. Each new
standard subsumes its
predecessors. For example, an
EGA board can also do
CGA
and
MDA.
With the
PS/2, IBM introduced the
VGA standard and built
it into the main system board
motherboard. VGA is also
available as a plug-in board for PCs from third-party vendors.
Also with the PS/2, IBM introduced the
8514 high-resolution
graphics
standard. An 8514 adaptor board plugs into the PS/2,
providing a dual-monitor capability.
Graphics software has to support the major IBM graphics
standards and many non-IBM, proprietary standards for
high-resolution displays. Either software vendors provide
display drivers, or
display vendors provide drivers for the
software package. In either case, switching software or
switching
display systems is fraught with compatibility
problems.
Display Resolution Colours Sponsor Systems
MDA 720x350 T 2 IBM PC
CGA 320x200 4 IBM PC
EGA 640x350 16 IBM PC
PGA 640x480 256 IBM PC
Hercules 729x348 2 non-IBM PC
MCGA 720x400 T
320x200 G 256 PS/2
VGA 720x400 T
640x480 G 16
SVGA 800x600 16 VESA
XVGA 1024x768 256 (IBM name: 8514)
T: text, G: graphics.
More colours are available from third-party vendors for some
display types.
See also
MDA,
CGA,
EGA,
PGA,
Hercules,
MCGA,
VGA,
SVGA,
8514,
VESA.