ocr: THE 8563 VIDEO CONTROLLER (Continued) External Registers The 8563, which sits at $D600 in the C128, appears to the user as a device consisting of only two registers. These two registers are indirect registers which must be programmed to access the internal set of thirty-seven programming registers. The first register, located at $D600, is called the Address/Status register. When written to, the five least significant bits convey the address of an in- ternal register to be accessed in some way. On a read of this register, a status byte is returned. Bit 7 of this register is low while display me ...
