Describe the features of Video controller

Question

Describe the features of Video controller?

Answer 1

• A fixed area of the system memory is reserved for the frame buffer and to the frame-buffer memory the video controller is given access

• To store the coordinates of the screen pixels Tow registers are used.

• The value is stored in the frame buffer for this pixel position is then retrieved and used to set the intensity of the CRT beam

• Initially the x register is set to 0 and they register is set to y-max

• Then the x register is incremented by 1 whereas process repeated for next pixel on top scan line

• This process is repeated for each pixel along the scan line

• After the last pixels on the top scan line have been developed x register reset to 0 where as y register is decremented by 1.

• From each successive line the procedure is repeated.