I wrote almost exactly this on C64 in the early 80's. The problem was that you couldn't see the ball moving very well because the pokes happened so rapidly comp

I wrote almost exactly this on C64 in the early 80's. The problem was that you couldn't see the ball moving very well because the pokes happened so rapidly compared to the rest of the code that it was a quick blink of the ball. It didn't look as clean and tidy as it does in this emulator. Also, my 12 year old brain wasn't smart enough to think of double buffering, or to draw the new position before erasing the old.