100 PRINT "PRIME FACTORING PROGRAM"
110 PRINT "INPUT POSITIVE INTEGER TO BE FACTORED:"
120 INPUT X1
130 PRINT "THE PRIME FACTORS ARE AS FOLLOWS:"
140 REM X2 REPRESENTS THE DIVISORS USED TO TEST NUMBER.
150 X2=2
160 GOSUB 300
170 X2=3
180 GOSUB 300
190 REM LINES 170 THROUGH 230 GENERATE ALL PRIVES REQUIRED
200 REM AS DIVISORS.  ALSO, SOME COMPOSITES ARE GENERATED,
210 REM BUT THE EQUATIONS REDUCE THE NUMBER CONSIDERABLY.
220 FOR N=0 TO SQR(X1)/6
230 X2=6*N+5
240 GOSUB 300
250 X2=X*N+7
260 GOSUB 300
270 NEXT N
280 GOTO 380
290 REM SUBROUTINE TEST DIVISIBILITY.
300 X4=INT(X1/X2)*X2
310 X4=INT(X1/X2)*X2
320 IF X4<>X1 THEN 370
330 PRINT X2;
340 X1=X1/X2
350 IF X1=1 THEN 390
360 GOTO 310
370 RETURN
380 PRINT X1
390 ?:?:?
400 INPUT "DO YOU HAVE ANOTHER NUMBER?";A$
410 IF A$="YES" OR A$="Y" THEN 110
990 ?:?:?
999 CHAIN "MATH2"
1000 END