| 摘要 |
A cathode ray tube is coupled to an electric circuit to display characters on the screen thereof through horizontal scanning and vertical scanning. A plurality of characters are displayed in one character group comprising characters arranged in rows and columns. A dispaly signal for displaying such characters is obtained from a random-access memory, which comprises a plurality of storing regions having addresses corresponding to the characters arranged in rows and columns forming a character group. When characters are to be displayed the logic one is loaded in the storing regions of the corresponding address, and when the characters are not to be displayed the logic zero is loaded in the storing regions in the corresponding address. The horizontal address of the random-access memory is determined by a counting operation for performing horizontal scanning, while the vertical address of the random-access memory is determined by a counting operation for performing vertical scanning. The horizontal address signal is obtained for a period corresponding to the scanning of the horizontal width of the character being displayed, while the vertical address signal is obtained for a period corresponding to the vertical width of the character being displayed. As a result, the same address information is obtained for that period from one storing region of the random-access memory, which is applied to a display as a display information signal. |
