wtm@neoucom.UUCP (Bill Mayhew) (10/11/88)
Hi, I am writing a TSR progaram that needs to pop up on a variety of video displays. The CGA screen is proving to be a minor annoyance. I need to be able to avoid the noxious CGA snow when I read or write to the CGA screen page 0 buffer at b8000. A while back I read that it is possible to program the 6845 video controller chip on the CGA board to generate an interrupt when it enters the vertical retrace interval and the CRT beam is off. Unfortunately, there was no mention of what the actual interrupt vector's value. I would appreciate it much if someone might be able to post a code fragment that illustrates trapping the retrace interrupt. --Bill wtm@neoucom.UUCP