Video Graphics Array (VGA) refers specifically to the display hardware first introduced with the IBM PS/2 line of computers in 1987,[1] but through its widespread adoption has also come to mean either an analog computer display standard, the 15-pin D-subminiature VGA connector or the 640×480 resolution itself. While this resolution was superseded in the personal computermarket in the 1990s, mobile devices have only caught up in the last few years.
VGA was the last graphical standard introduced by IBM that the majority of PC clone manufacturers conformed to, making it today (2013) the lowest common denominator that almost all post-1990 PC graphics hardware can be expected to implement. For example, the Microsoft Windows splash screen, in versions prior to Windows Vista, appears while the machine is still operating in VGA mode, which is the reason that this screen always appears in reduced resolution and color depth. Windows Vista and newer versions can make use of the VESA BIOS Extension support of newer graphics hardware to show their splash screen in a higher resolution than VGA allows.
VGA was officially followed by IBM's Extended Graphics Array (XGA) standard, but it was effectively superseded by numerous slightly different extensions to VGA made by clone manufacturers that came to be known collectively as Super VGA.
Today, the VGA analog interface is used for high definition video including 1080p and higher. While the VGA transmission bandwidth is high enough to support even higher resolution playback, there can be picture quality degradation depending on cable quality and length. How discernible this quality difference is depends on the individual's eyesight and the display; when using a DVI or HDMI connection, especially on larger sized LCD/LED monitors or TVs, quality degradation, if present, is prominently visible. Blu-ray playback at 1080p is possible via the VGA analog interface, ifImage Constraint Token (ICT) is not enabled on the Blu-ray disc.
Nessun commento:
Posta un commento