display standard

<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 has CGA and MDA capability.

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. The 8514 will be built into future models of the PS/2 line, as well.

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
 
  8514	   1024x768	256
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.

(10 May 1995)