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 Pin # HD15 VESA DDC (PnP) 1 Red 2 Green / Mono 3 Blue 4 Reserved 5 Ground 6 Red Ground 7 Green / Mono Ground 8 Blue Ground 9 +5V DC 10 Sync Ground 11 ID Bit 0 12 DCC Serial Data 13 Horizontal or Comp. Sync 14 Vertical Sync 15 DCC Serial Clock * ID Bits optionally input to the computer * Serial Clock and Data Lines are bi-directional