(VRAM) Fast memory designed for storing the image
to be displayed on a computer's monitor. VRAM may be built
from special memory integrated circuits designed to be
VRAM must be fast enough to supply data to the display
electronics at the speed at which the screen is scanned. Thus
for example, for a resolution of 1280x1024 eight-bit
pixels at a refresh rate of 70 Hz, the video memory
would need to supply 1280x1024x70 = 90 Mbyte/s or one byte
every 11 ns. The VRAM may be dual ported in order to allow
the display electronics and the CPU to access it at the same
In an IBM PC the VRAM is located on the display interface
card and 0.5 - 2 MB is typical.
A VRAM Song!