10 IFATHEN30
20 A=A+1:SYS2167:D=PEEK(186):LOAD"TM*",D,1
30 GETA$:IFA$<"1"ORA$>"4"THEN40
35 B=(ASC(A$)-49)*2
40 SYS2221:POKE767,B+64:SYS679