Abstract: A printer control apparatus provided with a CPU for converting video data supplied from an external unit to video data tailored to the operation of the printer; a memory holding various types of data during that conversion processing; and a read/write control unit performing the read/write control of the data between the memory, CPU, and the printer, which includes latch units which respectively latch the address and data from the CPU and thereby perform the processing at the minimum bus cycle. Also, the upper bit side of that address is made to include the control data from the CPU, and an autonomous read/write control is carried out. Further, that read/write control is carried out while using the video buffer comprising several standard size pages and by freely using that page.