CompuServe Messages

#Interlace problem

    28-Dec-91 06:40:08
Sb: #Interlace problem
Fm: David Oldis 72727,2460
To: ALL
Hello… This is a simple question, but through my lack of patience I've decided enough is enough <smile>. I'm having problems reading the Vertical beam position while in interlace mode, and blittering a 4 bitplane image. It seems to me that I could wait till the beam was at the bottom of the screen (during the even scans), then blit in the image, but it still flickers <sigh>. What is the trick in blittering in interlace. Isn't the LOF-frame flip-flop in VPOSR suppose to indicate if the lines being scanned are Odd or Even? Please help…. Thanks… David