Cathode ray tube controller.

摘要

A cathode ray tube controller (2l) holds a write-in address and displaying image data or a read-out address from a central processing unit (20), and makes access to a memory (22) by a write-in or read-out address from the central processing unit (20) during a period in which the displaying image data in a horizontal scanning period are not read out from the memory (22), so that the read or write operation with respect to the memory (22) can be carried out during the horizontal scanning period.