Mine got till the LONG overflow, that is up to and including 7FFFh

And just in 1,5 hour

It wasn't made in QB

. However, these are the test results with my program made in QB:

1 min: 2,000,000

2 min: 4,031,482

1 h: 240,482,843

Hey Neo...I'm fiddling with C the last couple days...here's a c port of my basic primer finder...on my 1.5 GHz after 6 min, the biggest prime was 190,976,059. This looks similar to what you reported re flipping the signed 4-byte int after 1.5 hr...Mine uses unsigned, so I get to go all the way to ffffffff, instead of cutting short at 7fffffff. Cheers.

#include <iostream>

using namespace std;

int main()

{

unsigned short inc = 1;

unsigned long c;

unsigned long x;

unsigned long stop;

unsigned long count=0;

unsigned long hold=1;

unsigned short array[6540]={3};

cout << "Find primes up to what number? (4,200,000,000 max)\n";

cin >> stop;

for (x=3; x<65536;x += 2) //get small primes, put in array

{

for (c=0; (x % array[c]) && (array[c]*array[c] < x) ; c++);

if (x % array[c])

{

//cout << x << " "; //use this line to show all primes

array[inc++]=x;

}

}

for (x=65537; x<stop;x += 2) //find large primes

{

for (c=0; (x % array[c]) && (array[c]*array[c] < x) ; c++);

if (x % array[c])

{

//cout << x << " "; //use this line to show all primes

if (count++ > hold)

{

cout << x << " "; //print every 100000th prime

hold += 100000;

}

}

}

cout << "\n done\n";

return 0;

}