Board Thread:Questions and Answers/@comment-24082751-20150220023206/@comment-24006222-20150224163509

Graphic flashing is an issue .... because you're clearing the entire screen (ACLS) then redrawing the graphic. I had that issue with COOKTMR1 in the first version. Adjusting the WAIT time from 1 to 5 or even 10 helped ... most of the time. But not always. When I first wrote COOKTMR1, I was blanking each clock face with a GFILL color 0 command, then redrawing the entire circle and filling it in with a GPAINT command, then drawing a rectangle. It blinked like crazy. The second time I wrote COOKTMR1, I decided to completely change the approach. The graphic area was left alone. Now it uses GPAINT to fill in the small rectangles that were just drawn with the 'background' circle color, then, it creates new rectangles. Hardly blinks at all, and a WAIT command isn't needed for the main loop. (WAIT pauses are always helpful after a button press, though...)

In your case, instead of using ACLS, it would be more effective to "undraw" your lines with color 0 before redrawing. Yes, it's more code, but it will work much better. Either no WAIT command will be necessary, or, it will be minimal (1 or 2 rather than 10 or 20). Remember that the faster the refresh, the smoother the action.