Graphics display control unit for characters or symbols - identifies blank spaces to reduce capacity of read-write display memory

摘要

A graphics display control unit for alphanumeric characters and graphical symbols receives horizontal synchronising signals by a counter (1) to define screen position. Code and address data are received by an input control circuit (2). A discriminator stage (3) and counter (5) determine spaces between characters or symbols. The output is entered into a read/write buffer memory (7) reduced in size by the elimination of empty sections indicating spaces. Space data are indicated by a counter (8) and a character ROM (9) supplies the display (14). ADVANTAGE - Reduced size of display memory.