Minimum amount of video RAM in raster system

Question

Assume a raster system having the resolution of 1024 x 768 pixels and color palette calls for 65,536 colors. Describe the minimum amount of the video RAM, that the computer should have to support the above-mentioned resolution and number of colors?

Answer 1

Color of each pixel on the display is represented with some number of the bits. Thus, a display capable of showing up to the 256 colors is utilizing the 8 bits per pixels (i.e. “8-bit color”).

Notice that the color palette calls for the 65,536 colors. This number is but 216 that implies that 16 bits are being used for representing the color of every pixel over the display. The display’s resolution is 1024 by 768 pixels that implies that there are a total of 786,432 (1024 × 768) pixels on the display. Thus, the total number of bits needed to show any of 65,536 colors on each of screen’s 786,432 pixels is 12,582,912 (786,432 × 16). Dividing this value by 8 gives an answer of 1,572,864 bytes. Dividing that value by 1,024 gives an answer of 1,536 KB. Dividing that value by 1,024 given an answer of 1.5 MB.