Editing Video Graphics Array (section)

===Signal timings===
The intended standard value for the horizontal frequency of VGA's {{resx|640x480}} mode is exactly double the value used in the [[NTSC-M]] video system, as this made it much easier to offer optional [[TV-out]] solutions or external VGA-to-TV converter boxes at the time of VGA's development. It is also at least nominally twice that of CGA, which also supported [[composite monitor]]s.

All ''derived'' VGA timings (i.e. those which use the master 25.175 and 28.322&nbsp;MHz crystals and, to a lesser extent, the nominal 31.469&nbsp;kHz line rate) can be varied by software that bypasses the VGA firmware interface and communicates directly with the VGA hardware, as many MS-DOS based games did. However, only the standard modes, or modes that at least use almost exactly the same H-sync and V-sync timings as one of the standard modes, can be expected to work with the original late-1980s and early-1990s VGA monitors. The use of other timings may in fact damage such monitors and thus was usually avoided by software publishers.

Third-party "multisync" CRT monitors were more flexible, and in combination with "super EGA", VGA, and later SVGA graphics cards using extended modes, could display a much wider range of resolutions and refresh rates at arbitrary sync frequencies and pixel clock rates.

For the most common VGA mode ({{resx|640x480}}, 60&nbsp;Hz, [[progressive scan|non-interlaced]]), the horizontal timings can be found in the HP Super VGA Display Installation Guide and in other places.<ref name="Javier Valcarce timings list">{{cite web|title=Javier Valcarce VGA timings page|url=http://www.javiervalcarce.eu/wiki/VGA_Video_Signal_Format_and_Timing_Specifications|url-status=live|archive-url=https://web.archive.org/web/20150102175843/http://javiervalcarce.eu/wiki/VGA_Video_Signal_Format_and_Timing_Specifications|archive-date=2015-01-02}}</ref><ref>HP D1194A Super VGA Display & HP D1195A Ergonomic Super VGA Display Installation Guide, Hewlett Packard</ref>