PRINTER CONTROLLER

PURPOSE:To reduce the memory capacity and to contrive to improve the economical properties with a printer control device by providing the valid bits for each fixed quantity of dot data of a full dot memory to set the valid bit when a fixed quantity of dot data is written and then to reset the valid bit when said dot data is read in a print mode. CONSTITUTION:When data are written to a full dot memory FDM, a single valid bit is added to a fixed quantity of data and reset when the dot data is read in a print mode. The FDM is prepared by an amount of capacity equivalent to a single page in the case of the character data only and the data equivalent to a single page is evolved to the FDM(0) for print. Then the next page is evolved to the FDM(0) after the dot data on the character corresponding to the valid bit of the preceding page is printed. Thus the print data and the evolution data on the next page exist at a time on the FDM(0). When a graphic print is available as an option, '1' never exists and therefore no queuing state is produced. While '0' never exists in a read mode.