Screen connections

Older computers, monitors and most computer projectors use an analog VGA connection with a HD15 connector. Older Macintosh computers have a smaller connection with a mini-VGA.
Many flat digital screen monitors have a connection following the DVI-standard (Digital Visual Interface) whic means the signal doesn't have to make a detour via analog. DVI was developed by a number of leading computer and monitor manifacturers and exists in a assortment of varieties: DVI-Analog (DVI-A), which only supports analog transfers and therefore works well with traditional CRT monitors. DVI-Digital (DVI-D), which only support digital transfers. DVI-Integrated (DVI-I) which supports both digital and analog transfers and therefore works with both digital and traditional monitors.
DVI can also have one or two channels. One channel can send 165 million pixel per second with 24 bits per pixel to the monitor. With one channel, called Single Link, the computer can handle monitors up to UXGA resolution (1600x1200 pixels) with a refresh rate of 60Hz. With two channels, called Dual Link, you can use monitors with very high resolution, HDTV (1920 x 1080 pixel), QXGA resolution (2048 x 1536 pixels), or even higher.
The connectors on the DVI cable are constructed so that they can't be connected in the wrong way, despite the fact that the connector for DVI exists in five variations, depending on wheter it handles analog and/or digital transfer, and in the digital transfer occurs in one or two channels. Monitors and video cards that are exclusively digital cannot be connected to analog, for exemple, even if they can be connected to the equipment that handles both analog and digital signals.
The DVI standard also supports DCC (Display Data Channel) and EDID (Extended Display Identification Data) that enables computer to communicate with the different extensions for monitor, for example in order to show wide-screen images.
To connect a monitor or projector with a VGA connection to computers with DVI requires that the DVI signal be analog, as well as the use of DVI-A to VGA adapter for connecting the signal.
Mini-DVI is a version of DVI that is used in some Apple laptops and, with the help of an adaptor, can be converted to DVI, VGA, S-video or composite video.

Main Menu

See Also

Main Menu