Colour graphics display with reduced screen memory requirement - uses two memories, one for each screen point with bit defining two colours allocated to it

摘要

The screen memory requirement for high resolution colour graphics display on a cathode ray tube screen is reduced by the use of two memories, the first, termed the point memory holds a single data bit corresponding to each screen point. The second, termed the colour memory, holds an m bit word pair which defines the two colours specified in the point memory. A micro processor accepts the screen data via a data bus, and under control of a clock transmits the data, appropriately divided, to the two memories. A multiplexer serialises the data flow to ensure transmission timing between sweeps of the cathode ray tube and an inhibit controller driven by the clock ensures synchronisation with the sweep timing.