| 摘要 |
A CRT terminal system uses two CPUs; one is for a system processor(1) and the other is for a video controller(2). This comprises a video ROM(3), a video display RAM(4), an address contention controller(5), a screen-line counter(6), a character generating ROM(7), a shift register(8), and a CRT displayer(9). The video ROM(3) comprises regions for stack, main program, dummy program segment, and scan-line counter reset. The refresh of a screen memory is automaitically performed while the videocontroller is operated with the data stored in the video ROM, because the corresponding address of the screen memory is matched with the address of the video ROM.
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