| Re: vsync var in basic?|
No, there isn't. BASIC is just too slow for that. Even checking $ff1d by peeking it wouldn't give you enough time to actually do anything before you reached the visible area again. Though honestly, I haven't tried this
Double buffering to avoid flickering might help a bit - but even then the switching of charsets/bitmaps might happen in the visible area. If you want to avoid flickering, go for assembler.
Nevertheless, there are BASIC programs around where the flickering doesn't hurt too much. It really depends on how much stuff needs to be updated. Poking a few chars to the screen is usually fine, whereas huge softsprites in BASIC - leave alone bitmap shapes - flicker like there's no tomorrow.
For the sake of not being discouraged at the first steps, I wouldn't mind the flickering! Just go ahead and code You can always come back to optimize stuff later.