[code=c]
#include<stdio. h>
#include<reg52. h>
void main()
{
int bit1, z=0;;

SCON = 0x50;
TMOD |= 0x20;
TH1 = 0xFA;
TR1 = 1;
TI = 1;
PCON |= 0x80;


printf("enter bit to set ? \n ");

scanf("%d", &bit1);

z = z | (1 << bit1);

...