C program Time delay help!

Dear sirs and madams

I present the following program to which i am simulating on a 8051 MCU

#include <reg51.h>

#include <stdio.h>
#define output P0

void main ()
{ unsigned int x;

while(1) { output = 1;

for(x=0; x<65000; x++) {

}

output = 0; for(x=0; x<65000; x++) {

}

}

My problem is that i am attempting to learn timing delays. For this program the P0 goes from 0 to 1 with a delay between. When i debug the program and run it with peripheral P0 open, it switches the value from 0 to 1 BUT the problem is its going to fast no matter how much delay i am putting in.

Please help me