The Video Graphics Array standard, commonly known as
VGA, was developed by IBM and became widely used in the 1980’s for PC monitor
displays. More common today, however, are the extensions and supersets of
VGA technology. VGA itself supports 16 colors at a resolution of 640x480 or
256 colors at a 320x200 resolution. The extensions and supersets of VGA, on
the other hand, which are commonly referred to collectively as Super VGA (
SVGA),
can handle higher color depths and resolutions starting from 800x600 and are used
by virtually every PC monitor and graphics card in use today. Be aware, however,
that the phrase “SVGA Compatible”, as seen on most of today’s monitors and graphics
cards, is virtually meaningless in describing exactly what VGA extension is being
used. In order to achieve the best possible video performance, the graphics
card and the monitor must support the same resolutions, color depths, and refresh
rates, in other words, they both must use the same VGA extension. Included under
the SVGA umbrella are the 8514/A superset, the Extended Graphics Array (XGA), and
the
Video Electronics Standards Association’s
(
VESA) VESA Bios Extension (VBE), the latter
being the standard VGA extension in use today. The VESA Bios Extension allowed
for a virtual guarantee of software compatibility in the face of numerous incompatible
VGA extensions.
The connection type commonly used for VGA and SVGA monitor cables today is a 15-pin
VESA
DDC (
PnP)
High Density D-Sub connector (HD15), which consists of 3 rows of 5 pins each, which
are thinner than the normal D-Sub connectors (DB). Macintosh monitors, however,
require a DB15 connector, wherein the 15-pin layout is organized in only 2 rows.
Following are the pin assignments for today’s monitor cables:
VGA / SVGA
(HD15) Plug