10 INK 0:PAPER 7:BRIGHT 0:BORDER 7:CLS
         30 LET R=65533:LET D=49149
         40 OUT r,7:OUT d,62
         50 LET G=1750000/16
         60 REM  F(clock AY)=1.75 MHz
         70 INPUT "F(Hz)=";F:IF F>G OR F<g/4095 THEN GO TO 70
         80 LET a=INT (G/f+.5):LET a1=INT (a/256):LET a0=(a-a1*256)
         90 OUT r,0:OUT d,a0
        100 OUT r,1:OUT d,a1
        110 OUT r,8:OUT d,15
        120 PRINT "  ";G/(a-1)'"F=";G/a;" Hz"'"  ";G/(a+1)
        130 PRINT ''''a;"  -  ";a1;" , ";a0
        140 PAUSE 0:CLS
        150 OUT r,8:OUT d,0
        160 GO TO 70