/***********
 *
 *  lptbusy.c monitors the lpt1 busy pin
 * (#11 on db25 and centronics for state
 * changes and reports the times
 *
 *
 */

#include <dos.h>   /* Contains the prototype for inportb */
#include <stdio.h> /* Contains the prototype for printf */
#include <time.h>

#define MAXEVENTS 1000
#define MAXITERATIONS 5600000

int main(void)
{
 long int li_iterations;
 int a,old,i,j;
 uclock_t time, timeout, data[MAXEVENTS+1];

 a = inportb(0x378 + 1); /* Gets input from Status Port in byte form. */
 printf("\
# lptbusy.c - monitors a PCs lpt1 pin 11 (BUSY)\n\
#      for about 10 seconds or 1000 state changes\n\
#      then prints a report to stdout.\n\
#      You can short a ground pin to 11 for a signal. \n\
#  Dave Forrest drf5n@virginia.edu 1/11/98\n\
#  source available at http://mug.sys.virginia.edu/~drf5n/extras\n\
#  See also http://www.geocities.com/SiliconValley/Bay/8302/parallel.htm\n\
");

 printf("# lpt1 port status (0x378+1): %d bit 7 (128) is BUSY\n",a); /* Prints byte value to screen in */
    i=0;
    old = inportb(0x378+1) & 128;
    time = uclock();
    li_iterations = 0;
    while( (i < MAXEVENTS)&& (li_iterations < MAXITERATIONS)) {
      li_iterations++;
      a = inportb(0x378+1)&128;
      if ( a != old)
       {

           data[i++]= time = uclock();
           old = a;
       }
    }
    time = uclock();
    printf ("# Done!\n %ld iterations in %lf secs",
           li_iterations, (double)time/(double)UCLOCKS_PER_SEC);
    printf ("# Done!\n\n Cycle Open / close\n");
    for (j=0; j <i; j+=2){
       printf("%d : %lf / %lf\n",
             j,
             (double)( data[j] / (double) UCLOCKS_PER_SEC),
             (double)data[j +1 ] / (double) UCLOCKS_PER_SEC);
    }
    return 0;
}