
https://retrobasic.allbasic.info/index.php?topic=341.msg2329#msg2329

Erm, instead of

--LOOP----------------------
repeat
    redraw()
until getkey() == 41
----------------------------

better use

--LOOP----------------------
repeat
    sync()
until getkey() == 41
----------------------------

otherwise your CPU will go up on 100% while the loop runs. Actually you could even add a wait(20) behind sync().
