| 摘要 |
<p>PURPOSE:To speedily plot display data and scroll the screen on the display device which has a screen buffer larger than the display screen size of the display device. CONSTITUTION:When the data are plotted on a screen buffer 2 at a first time, only data 11, 12, 21, 22 and 23 of a part 3 of the screen buffer 2 which appears on a display 1 are plotted on the buffer 2 and flags are set on the data which are already plotted. Then, when the display position of the display 1 is changed to a position 4, only data 13, 14, 24 and 25, which newly appear on the display 1, are plotted. At that time, the data 23, on which a flag is set, are not plotted. Therefore, no unnecessary data are plotted on the buffer 2 and high speed scrolling, display data plotting and replotting are performed.</p> |
