| 摘要 |
PURPOSE:To reduce the scale of a program, by transmitting automatically a line synchronizing signal synchronously with a picture data signal when a picture data is transmitted to a printer, etc. CONSTITUTION:When a picture data signal is transmitted to a printer, the data transfer is requested to a CPU with a signal obtained by frequency-dividing 56 a data transmitting timing clock CL signal fed from the printer. The CPU reads out data D0-D7 of prescribed addresses of a display RAM7 and holds the picture data at a holding circuit 54 to apply a parallel-series conversion 55 to the held picture data. When addresses A0-A4 of an address bus 22 are set at L level, the output of an OR circuit 51 is set at H level. A signal SFF is supplied to a parallel-series converting circuit 52 by means of the signal which held 53 the picture data. Thus a series data is obtained. An output line synchronizing signal SY and a data signal DT are set at H and L levels respectively at terminals 81 and 82 and for a prescribed period CL. When the CPU sets the address Ao at H level, the output of the circuit 51 is set at L level. Thus no signal SFF is supplied to the circuit 52, and the signal SY is set at L level. Then the picture data is transferred through the terminal 82. |
