Method and apparatus for utilizing off-screen memory as a simultaneously displayable channel

摘要

A method and apparatus for the storage and retrieval of pixel information, including first and second data portions, is shown to include first and second memory devices each having a random access memory and a shift register, wherein the random access memory includes an on screen section and an off screen section. Pixel information is retrieved from the random access memories in response to control signals and transferred to the shift registers. A controller controls the storage and retrieval of the first data portion in the on screen section of the first memory device, controls the storage and retrieval of the second data portion in the off screen section of the second memory device and generates the control signals so that the first and second data portions are outputted from the shift registers simultaneously.