| 摘要 |
<p>PURPOSE:To display CRT display data different in scanning frequency from an arbitrary position by dividing vertically to right and left by switching the reading data of a horizontal period with a data switching signal. CONSTITUTION:A comparing means 12 compares a displaying starting position from a displaying starting position generating circuit 7 and the counted value of a clock from a writing pixel clock circuit 6. When coincident, a RAM address circuit 13 generates a writing address and generates a reading address by the clock from a reading pixel clock circuit 5. The data from a character string data memory 17 stored in a RAM 14, and the data from an image data memory 16 are switched by a data switching circuit 15 and displayed to a CRT display 1. Thus, the data having the scanning frequency can be synthesized and displayed to one CRT display image data.</p> |
