10 IFA=0 THEN A=1:LOAD"ZS",8,1
20 IFA=1 THEN A=2:LOAD"INF",8,1
30 IFA=2 THEN A=3:LOAD"C800",8,1
40 PRINT"[147]":POKE53281,0:POKE53272,29:SYS51200
50 GETA$:IFA$="" THEN 50
60 POKE53281,6:POKE53272,21