You can do it with very little. Prime example: https://www.folklore.org/StoryView.py?project=Macintosh&story=Apple_II_Mouse_Card.txt https://www.folklore.org/St

You can do it with very little. Prime example: https://www.folklore.org/StoryView.py?project=Macintosh&story=Apple_II_Mouse_Card.txt https://www.folklore.org/StoryView.py?project=Macintosh&stor...; drawing a mouse pointer on an almost stock Apple II, flicker-free because drawing is synced to the vertical blank interval, even though the hardware cannot see when that happens (that part I don’t quite understand; I can see them detecting ‘end of screen’ on an almost blank screen and programming the timer to generate a periodic interrupt at about the screen redraw frequency, but wouldn’t the VBL and the 6522 interrupts drift away from each other over time?)