10 CLS 15 PRINT "Svalestup kj›rer..." 17 f = 37 20 SOUND f, 1 22 LOCATE 2, 1 25 PRINT f; "Hz " 30 LET f = f + 50 40 IF f > 2500 THEN GOTO 60 50 GOTO 20 60 SOUND f, 1 62 LOCATE 2, 1 65 PRINT f; "Hz " 70 LET f = f - 50 80 IF f < 37 THEN END 90 GOTO 60