< 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 .