3 Interface Devices and Mass-Storage Drives
Matrox MGA Millennium Graphics Controller Board
Connectors
The Video Electronics Standards Association (VESA) defines a standard video connector, variously known as the VESA feature connector, auxiliary connector, or pass-throughconnector. The video controller supports an output-only VESA feature connector in VGA mode. This connector (whose pin names are listed in a table on page 58) is integrated on the PCI board, is connected directly to the pixel data bus and the synchronization signals, and is automatically enabled all of the time.
There are two connectors on the back panel: the normal DB15 VGA connector, for connecting to HP displays, and a Media XL connector (used by the MPEG accessory, not supported by HP). The layout of the pins for the DB15 VGA connector are shown on page 62.
If you install a VESA-standard video accessory board that uses the MGA video adapter, connect the accessory board’s cable to the VESA pass- through connector on the board.
Video Memory
The video memory (also known as window RAM, or WRAM) is a local block of RAM for holding two major data structures: the double buffer (to hold one frame steady on the screen whilst the next one is being processed), and the Z-buffer (for storing depth information for each pixel). It is dual ported, so that it can be inputting and outputting simultaneously. There is also hardware support for Gouraud shading, Phong shading and texture mapping.
The Matrox MGA Millennium graphics controller board is supplied with 2 MB of video memory. This can be upgraded to 4 MB with a D3557B upgrade module, or to 8 MB with an MGA-MIL/MOD6 upgrade module (ordered from Matrox). The upgrade socket can alternatively be used for the installation of the Matrox MGA Media XL upgrade module (also ordered from Matrox) to support MPEG. The switch settings do not have to be changed.
Available Video Resolutions
The number of colors supported is limited by the graphics device and the video memory. The resolution/color/refresh-rate combination is limited by a combination of the display driver, the graphics device, and the video memory. If the resolution/refresh-rate combination is set higher than the display can support, you risk damaging the display.
