Display processor updating its color map memories from the serial output port of a video random-access memory

In a system, for providing data representing images for display on a display device, including a random-access memory for storing bit mapped image data and color map memory program data, said random-access memory having a serial output port, said system further including a display processor compising:

• a display processor input port coupled to the serial output port of said random access memory;
• a color map memory having an address input port and a data input/output port;
• an address generator having an output port for providing address codes and having a control input port;
• read/write control circuitry coupled to said display processor input port and responsive to data provided by said random access memory, and including;
• (a) an output port coupled to the control input port of said address generator for controlling sequences of address codes produced thereby;
• (b) means for selectively coupling said display processor input port or the output port of said address generator to the address input port of said color map memory;
• and
• (c) means for selectively coupling said display processor input port to the input/output port of said color map memory when the output port of said address generator is coupled to the address input port of said color map memory, whereby color map memory program data from said random access memory may be written into said color map memory.