relation to the synchronous operation of the laser printer machine system lzpmcn with the print data supply system in the manner described above the refresh address generator rfgen generates the refresh timing derived from the predetermined refresh interval in synchronization with the output request of the print address data thus the refresh address output control can be coordinated with the print data output address operation control derived from the status of the laser printer machine system lzpmcn 1 the address operation processing by the print output address operation controller lzctr is not sequentially executed and synchronized to a predetermined timing signal rather the operation is coordinated with the state of the laser printer machine system lzpmcn derived from the line changing signal cr the page changing signal cp and the print address output request signal prreq therefore the print output address operation control can be accomplished by a simpler circuit configuration than a system requiring complex timing adjustment circuits to synchronize the state change of the laser printer machine system izpmcn with the print output address operation 2 the simple circuit construction can supply the necessary print data to the laser printer machine system lzpmcn and can compensate for timing changes due to page changes occurring from events such as paper or ink shortage compared with a display controller used for laser printer control the present invention can eliminate additional timing adjustment circuits thus simplifying the control system therefor 3 the refresh address generator rfgen coordinates the memory refresh operation during a predetermined refresh interval with the output request of the print address this coordination is accomplished with signals.