Display system including a refresh memory with variable line start addressing.

摘要

The display system includes a processor (50) loading the address of each line start character into the pointer area of a refresh memory (9) with variable line start addressing and a line counter (5) which counts the lines being displayed on the display (1). The RAM refresh memory (9) which contains the line start addresses and character data is first addressed by the line counter outputs (11-15) by the intermediary of a multiplexer (7). Since the refresh memory (9) is used as the line pointer register the output bus (4) for pointer data and character data is common. Once the address of the first character in a line is read from the pointer area in the refresh memory it is loaded into the address counter (6) which then controls the sequential reading of characters in that line from the refresh memory (9) onto the data bus (4). Following the reading of each line the sequence is repeated, e.g, the line counter (5) is incremented, its count used to address the pointer area and the address contained therein loaded into the address counter (6).