REM WAIT UNTIL FIRST PERIOD IS PAST
10  PRINT 'CHECKING RTC'
15  GOSUB 200
REM GET INITIAL CALIBRATION POINT
20  PRINT 'ENTER CURRENT HUMIDITY (10-90)'
25  INPUT H
30  IF 90<H THEN GOTO 20
35  PRINT 'CHECKING SENSOR OUTPUT'
40  GOSUB 200
REM SAMPLE THE FREQUENCY
45  F=FREQ0 : PRINT 'FREQUENCY = ';F
50  PRINT 'PLACE SENSOR IN NEXT SOLUTION'
REM GET SECOND CALIBRATION POINT
55  GOSUB 200
60  PRINT 'ENTER NEW HUMIDITY (10-90)'
65  INPUT I
70  IF 90<I THEN GOTO 60
75  PRINT 'CHECKING SENSOR OUTPUT'
80  GOSUB 200
85  G=FREQ0 : PRINT 'FREQUENCY = ';G
REM CALCULATE THE DF/DH
90  K=(F-G)/(H-I)
95  PRINT 'CALIBRATION = ';K;' HZ/PERCENT'
100 PRINT
105 PRINT 'FREQ  HUMIDITY'
110 PRINT '--------------'
115 GOSUB 200
120 M=FREQ0 : R=H+(M-F)/K
125 PRINT M,R
130 GOTO 115
REM SUBROUTINE TO WAIT UNTIL NEXT SECOND
200 A = DBY 49
205 IF A = DBY 49 THEN GOTO 205
210 RETURN