10 P=0
20 RESTORE 130:GOSUB 60 : rem ch1
30 RESTORE 150:GOSUB 60 : rem ch2
40 RESTORE 170:GOSUB 60 : rem ch3
50 END
60 FOR I=0 TO 31
70 OUT&H78,P
80 P=P+1
90 READA$:A=VAL("&H"+RIGHT$(A$,2))
100 OUT&H79,A
110 NEXT I
120 RETURN
130 DATA ~
150 DATA ~
170 DATA ~