| 摘要 |
The picture stored in memory (BWS) with a total of 4096 x 4096 pixels is reproduced on a display screen (SG) measuring 1024 x 1024 pixels by scrolling with the addn. (ADX, ADY) of the counts from picture counters (AX, AY) and scrolling counters (RX, RY). Horizontal and vertical movement pulses (delta x, delta y) are chosen for a mouse controller (BE) by cursor position counters (CX, CY). In the scrolling mode the cursor (CU) is set in a definite (e.g. central) position on the screen (BS) so that when the edge of the selected picture segment (BD) reaches the edge of the screen, the cursor (CU) is shifted and when the cursor attains its set position the picture is scrolled.
|
