10 IF A=0 THEN A=1:LOAD"SPACE SPRITE",8,1
20 IF A=1 THEN A=2:LOAD"DUEL.EXE",8,1
30 IF A=2 THEN PRINT"[147]"CHR$(142)
40 POKE 53271,0:POKE 53277,0:SYS 49152