1 CLS : PRINT "          PRIME NUMBER TESTING PROGRAM"
2 PRINT "               by Phillip Bigelow"
3 PRINT : PRINT : PRINT : PRINT "This program can test numbers from one through 16 digits long."
4 PRINT "(testing larger numbers gives unreliable results due to round-off error)":PRINT:PRINT "Note: The computer will appear to hang when large numbers"
5 PRINT "are tested."
6 PRINT "Don't let the long delay upset you! The program is working!"
9 PRINT "Very large numbers can require a few hours to a few days to test.": PRINT : PRINT
10 PRINT : INPUT "What is the number you want to test";Q#
11 CLS
12 PRINT "Program is now running.....To stop program, press (Ctrl) and (Pause) keys"
14 PRINT "simultaneously.": PRINT : PRINT : PRINT "Testing number"; Q#
15 PRINT : PRINT : PRINT
16 LET B$=TIME$
17 LET X#=2#
20 LET Y#=Q#/X#
21 IF Q#=1 THEN 50
22 IF Q#=2 THEN 50
34 IF Y#=INT(Y#) THEN PRINT "--------------------------RESULTS-------------------------"
35 IF Y#=INT(Y#) THEN PRINT "The number"; Q#; "is NOT prime": PRINT
36 IF Y#=INT(Y#) THEN PRINT "divisible by", X#
38 IF Y#=INT(Y#) THEN 52
39 IF Y#=INT(Y#) THEN 100
41 LET X#=X#+1
42 IF X#>INT((Q#/2)+1) THEN 50
45 GOTO 20
50 PRINT "-------------------------RESULTS--------------------------"
51 PRINT "YOU HAVE A WINNER!", Q#; "Is A PRIME NUMBER!!!"
52 PRINT "Calculation began at = ";B$
53 PRINT "Calculation ended at = ";TIME$
54 PRINT "----------------------------------------------------------"
55 PRINT
56 IF Y# = INT(Y#) THEN 39
100 PRINT "                MENU":PRINT "Test another number (t), or exit to system/Windows (x)":JH$=INPUT$(1)
101 IF JH$="t" THEN 1
102 IF JH$="x" THEN SYSTEM
103 CLS:GOTO 100