If the Apple 1 computer came with INTEGER BASIC, then how am I doing BIORHYTHM?

9000 REM SIN/COS (DEGREES) INPUT A, OUTPUTS S, C

9010 S = ((A MOD 360)+360) MOD 360: REM GET ANGLE 0-359

9020 IF S < 180 THEN 9060

9030 IF S < 270 THEN 9050

9040 C = C5(S-270+1): S =-C5(360-S+1): RETURN: REM 270-359

9050 C =-C5(270-S+1): S =-C5(S-180+1): RETURN: REM 180-269

9060 IF S < 90 THEN 9080

9070 C =-C5(S-90+1): S = C5(180-S+1): RETURN: REM 90-179

9080 C = C5(90-S+1): S = C5(S+1): RETURN: REM 0-089

9800 REM SET UP TABLE

9810 DIM C5(91)

9820 S=0: C=8192

9830 FOR A = 0 TO 45

9840 C5(A+1) = S: C5(90-A+1) = C

9850 S=S+((C/3)*10)/191

9860 C=C-((S/3)*10)/191

9870 NEXT A

9880 RETURN

First I set up an array to hold SIN for 0 to 90 degrees. (You don’t need more if you know COS is SIN of the angle plus 90, and other quadrants are symmetrical).

But, creating an array of 91 values would pretty much take up all of available programming space, so I generated it using the differential equations — relating SIN and COS. I also made the values go from 0 to 8192, as going from 0 to 1 is not useful.