| 摘要 |
<p>A CPU communicates over a bus (203) with a liquid crystal display (LCD) device (209) by way of a control unit (217), a display memory (213) and another control unit (219). The memory (213) includes a screen image RAM (223) which is a pixel memory cyclically accessed by the latter control unit (219) to keep the display refreshed. The former control unit (217) keeps the contents of the screen image RAM (223) updated in accordance with ASCII codes in a RAM (221), each with an associated attribute code. The control unit (217) converts ASCII character codes into corresponding groups of pixel codes written into the screen image RAM (223) by reference to a font pattern RAM (225). ASCII graphic codes are passed to the screen image RAM (223) without conversion but, in either event, the attribute codes selectively modify what goes into the screen image RAM (223), on a character by character basis, to determine whether normal or reverse video is employed, blinking characters are employed, a high speed, imperceptible blinking is employed to provide an intermediate visual tone and to implement a form of colour emulation in which colour codes in the attribute codes select the background tone (and complementary foreground tone) of the display.</p> |
