video memory

storage The memory in a computer's graphics adaptor, used

to store the image displayed on a bitmap display. Often

this is built using VRAM chips. There is normally a simple

correspondence between groups of bits in video memory and

the dots or "pixels" on the screen, such that writing to a

given group of bits will alter the appearance of a single dot.

If each pixel corresponds to eight bits then it can have any

of 256 colours (or shades of grey on a monochrome display).

The video display electronics is responsible for reading the

data from video memory and converting it into the necessary

signals to drive the display. Often this includes a colourpalette which converts pixel values into RGB triplets.

(1996-11-01)