Accessing Parallel Port: outb and ioperm Problem

[Nazifa]

Hello,

I am a new user and want to generate a TTl pulse by parallel port finally. Presently I am trying to get high and low values at the data pin.

But I am getting segmentaion error.

My question are:
How do I remove this error?
with base = 0x378 means I can access the first data pin? Is it? and 0x379 means second data pin and so on?

Please help me out.
thanks

Code:


/* Generate pulse by parallel port
with min and max exposure time
Exposure time is controlled by the width of the pulse
*/


#include <stdio.h>
#include <sys/io.h>


int base=0x378;
int result;
int value;

int main( )
{

// /*s The line below is used to change the privelege level
// gives access with associated risks
// */
// result = iopl(3); /* Returns 0 on success , 3 = Modes*/
// {printf ("IOPERM %d\n\n", result);}

/* The two lines below gives access to the addresses else you get
'Segmentation Fault' that is accessing restricted addresses.
If success then you get 0 else -1
*/

result = ioperm(base,8,0); // 1 = on
{printf ("IOPERM = %d\n\n", result);}

// while(1)
// {

printf("High\n");
int value = 0xff;
printf("outb(%02X,%04X)\n",value,base);
outb(value,base);


printf("Low\n");
value = 0x00;
printf("outb(%02X,%04X)\n",value,base);
outb(value,base);

//usleep(10000000); //Adds wait
// }
}

[Nazifa]

/* Generate pulse by parallel port with min and max exposure time.
Exposure time is controlled by the width of the pulse */

#include <stdio.h>
#include <sys/io.h>

int base=0x378;
int value,i;

int permission()
{
/* The line below gives access to the addresses else you get
'Segmentation Fault' that is accessing restricted addresses.
If success then you get 0 else -1
*/
return ioperm(base,1,1);
}

int main( )
{

// Get permission to access
permission();

// Infinite pulses
// while(1)

// Ten pulses of equal duration , 50 % duty cycle
for (i=0;i<11;i++)
{
printf("High\n");
int value = 0xff;
printf("outb(%02X,%04X)\n",value,base);
outb(value,base);

usleep(10); //Waits for micro secs
/*
printf("Low\n");
value = 0x00;
printf("outb(%02X,%04X)\n",value,base);
outb(value,base);

usleep(10); //Waits for micro secs*/

}
printf("Number of pulses %d\n",i-1);
}