display standard

display standard

(hardware)IBM and others have introduced a bewilderingplethora of graphics and text display standards for IBM PCs. The standards are mostly implemented by plugging in avideo display board (or "graphics adaptor") and connectingthe appropriate monitor to it. Each new standard subsumes itspredecessors. For example, an EGA board can also do CGAand MDA.

With the PS/2, IBM introduced the VGA standard and builtit into the main system board motherboard. VGA is alsoavailable as a plug-in board for PCs from third-party vendors.Also with the PS/2, IBM introduced the 8514 high-resolutiongraphics standard. An 8514 adaptor board plugs into the PS/2,providing a dual-monitor capability.

Graphics software has to support the major IBM graphicsstandards and many non-IBM, proprietary standards forhigh-resolution displays. Either software vendors providedisplay drivers, or display vendors provide drivers for thesoftware package. In either case, switching software orswitching display systems is fraught with compatibilityproblems.

Display Resolution Colours Sponsor Systems

MDA 720x350 T 2 IBM PCCGA 320x200 4 IBM PCEGA 640x350 16 IBM PCPGA 640x480 256 IBM PC

Hercules 729x348 2 non-IBM PC

MCGA 720x400 T320x200 G 256 PS/2

VGA 720x400 T640x480 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 somedisplay types.

See also MDA, CGA, EGA, PGA, Hercules, MCGA,VGA, SVGA, 8514, VESA.