'===========================================================================
' Subject: FIND PRIME NUMBERS UP TO 31991     Date: 05-11-00 (00:37)       
'  Author: Dieter Folger                      Code: QB, QBasic, PDS, PB    
'  Origin: folger@bnv-bamberg.de            Packet: ALGOR.ABC
'===========================================================================
'----------------------------------
'PRIME.BAS for QBasic or Powerbasic
'Finds the prime numbers up to 31991
'and writes them to PRIME.DAT
'----------------------------------
DEFINT A-Z
DIM p(32000)
OPEN "PRIME.DAT" FOR OUTPUT AS #1
FOR i = 3 TO SQR(32000) STEP 2
    FOR j = i * i TO 32000 STEP 2 * i
        p(j) = 1
    NEXT j
NEXT i
PRINT #1, 2 'first prime number
FOR i = 3 TO 32000 STEP 2
    IF p(i) = 0 THEN PRINT #1, i
NEXT i
CLOSE
PRINT "Done"
END