SCROLLING METHOD USING PARAMETER IN A CRT CONTROLLER

摘要

The scrolling is done by scan line units so that fatigue of eyes is decreased. The method comprises the steps of: (A) checking the initial parameter intermission counter(PIC); (B) checking that the interrupt counter value is 17; (C) converting data in a video memory when one scan line is scrolled up; (D) initializing the vertical back porch(VBP) and the vertical front porch(VFP) by 24; (E) resetting the interrupt counter(IC); (F) decreasing the VBP by 1 and increasing VFP by 1; (G) increasing the PIC by 1; (H) comparing the PIC and an user intermission counter; and (I) resetting the PIC when the PIC is larger than the UIC.