Abstract: Magnetic recording apparatus for recording data onto a recording medium comprises a rotary drum with recording heads and reproducing heads which are disposed spaced from each other to confirm whether correct data is recorded onto the recording medium. In response to the detection of erroroneous recording, the transfer of new data to the recording heads is interrupted and misrecorded data is re-recorded onto the recording medium.

Abstract: A graphic image is displayed on a CRT screen according to the coordinate data which is sequentially read out of a memory. The memory comprises a first storage area which stores character image coordinate data and a second storage area which stores graphic image data such as signal wave. The ratio of addressing times for the first and second storage areas of the memory is set to 1:n. Accordingly, the graphic image is irradiated on the CRT screen n times more than that of one character image. Since the irradiation period of time of each spot is defined by a clock pulse width, there is no irradiation variation from one spot to another spot.