| |
|
VGA refers to A "array (array)" rather than "converter (adapter)", because it was designed from the beginning to the integration of A single chip, is used to replace the Motorola 6845 and dozens of discrete combination logic chip ISA stamper, before the design is used by MDA, CGA and EGA. VGA colonization of this feature allows them to easily into PC motherboard, only need extra video memory, oscillator and a a RAMDAC, it can display function. The IBM PS / 2 computer series is the placed VGA in the design of the motherboard. VGA specification is as follows: 256 KiB Video RAM 16 and 256 color color mode Color version of the a total of 262144 kinds of colors (red, green, blue three colors each 6 bit, a total of three) (26) Selective 25.2 MHz and 28.3 MHz frequency processing Level of up to 720 pixels Up to 480 lines The update frequency of up to 70 Hz Vertical Blanking interrupt (not all card support) Planar pattern: up to 16 color (4 bit panel) The color of the Packed - pixel patterns: 256 (Mode 13 h) Smooth animation skills Some "Raster Ops" support Barrel shifter Support the split screen VGA support can separate operation pixels of APA (All Points Addressable) model, also support text mode of letters and Numbers. Standard graphics mode is as follows: 640 x 480 x 16 colors 640 x 350 x 16 colors 320 x 200 x 16 colors The color of 320 * 200 * 200 (Mode 13 h) It also support with the resolution of the simulation way to draw the previous specifications: EGA, CGA and MDA. |
