After a bit of a ponder this should be about as fast as you can get
without putting multiple statements on one line ..
1 GOTO 5
2 WAIT A,D,D
3 POKE B, PEEK(C)
4 GOTO 2
5 A=61456
6 B=61441
7 C=61457
8 D=1
9 GOTO 2
.. if multiple statements per line are allowed then this should be
faster ..
1 A=61456:B=61441:C=61457:D=1
2 WAIT A,D,D:POKE B,PEEK(C):GOTO 2
Lee.