/*--------------------------------------------------------------------
 *               C LANGUAGE SAMPLE 0
 *
 * Sample program for the Watchdog Serial Interface card
 * demonstrating register level programming.
 *
 * Last Modification : 21 November 1994.
 *------------------------------------------------------------------*/

#include <stdio.h>
#include <stdlib.h>
#include <conio.h>
#include <ctype.h>
#include <dos.h>

#define _10secLo 0xCA
#define _10secHi 0x08

unsigned base;


unsigned AskForBaseAddress(unsigned int OldOne)
   {
   char msg[81];
   unsigned int NewOne=0;

   window(5,5,75,19);
   textcolor(WHITE);
   textbackground(BLUE);
   clrscr();
   window(10,7,70,17);
   cprintf("\n\n\nPlease enter the Base Address for your card (in hex)\n\r"
         "or press ENTER for %X.\n\r"
         ">",OldOne);
   msg[0]=5;
   cgets(msg);
   sscanf(msg+2,"%x",&NewOne);
   textcolor(LIGHTGRAY);
   textbackground(BLACK);
   window(1,1,80,24);
   clrscr();
   return ((NewOne>=0x100)&&(NewOne<=0x3f0)) ? NewOne : OldOne;
   } /* end of AskForBaseAddress */


void intro(void)
   {
   clrscr();
   puts("Sample          ");
   puts("\n");
   puts("This sample program simulates the Watchdog timer in action.");
   puts("The program sets the Watchdog timer to provide a 10 second");
   puts("fault monitoring polling interval. If a key is not pressed");
   puts("within that  interval, the Watchdog  will alert the system");
   puts("that a failure has occured.");
   puts("\n");
   puts("\n");
   puts("\n");
   puts("\n");
   puts("Please press ENTER to set base address.");


   getch();
   clrscr();
   base = AskForBaseAddress(0x350);
   clrscr();

   printf("Address entered was %X hexidecimal.\n", base);
   printf("Is this the correct address for your configuration? (Y/n)");

   while(!kbhit());
   if (toupper(getch()) == 'N')
      {
      printf("\n\nPlease restart program and enter correct address.\n");
      exit(1);
      }
   } /* end of intro */


void main(void)
   {
   int  secs1, secs2;
   int  count;

   intro();

   clrscr();
   puts("The Watchdog is on patrol!");
   puts("\n");
   puts("Press any key to issue the 'all clear' message and");
   puts("reset the Watchdog timer, or wait ten seconds for ");
   puts("time out and error response.");
   puts("\n");

   outportb(base+3, 0xB0);                    /* Select Watchdog counter */
   outportb(base+2, _10secLo);                        /* Set counter LSB */
   outportb(base+2, _10secHi);                        /* Set counter MSB */
   secs2 = ((_10secHi << 8) + _10secLo) / 225;     /* Init seconds count */
   delay(50);

   do
      {
      if (kbhit()) /* then reset Watchdog */
         {
         getch();                               /* Clear keyboard buffer */
         printf("   'All clear!' -- Watchdog reset.\n");
         delay(100);
         sound(1200);
         delay(50);
         nosound();
         delay(100);
         sound(1200);
         delay(50);
         nosound();
         delay(200);

         outportb(base+3, 0xB0);          /* Select the Watchdog counter */
         outportb(base+2, _10secLo);      /* Load a 10 second countdown  */
         outportb(base+2, _10secHi);
         secs2 = ((_10secHi << 8) + _10secLo) / 225;
         delay(50);
         } /* of if keyboard hit */

      outportb(base+3, 0x40);               /* Latch current timer count */
      count = inportb(base+2);              /* Read counter LSB/MSB      */
      count = count + (inportb(base+2) << 8);
      secs1 = (count / 255) + 1;            /* Convert to seconds        */
      if (secs1 < secs2)
         {
         secs2 = secs1;                     /* if new secs < prev secs   */
         printf("%d  ", secs1);             /* Display new seconds       */
         sound(720);                        /* Sound a clock tick        */
         delay(20);
         nosound();
         } /* end if secs */

      } while (count >= 0);                  /* Time's up!               */

   puts("\n");
   puts("\n");
   puts("                        WOOF!!");  /* Issue Watchdog warning   */
   sound(1200);
   delay(400);
   nosound();

   puts("\n");
   puts("   Had this been  an actual emergency,  Watchdog");
   puts("   would have taken appropriate fail-safe action.");

   } /* end of main */