#define BASEADDR  0x300
  /*declare base address for IOD-24 card*/
#define ON        1
  /*create some useful constants*/
#define OFF       0
  /*...*/

#include "stdio.h"
#include "conio.h"
#include "time.h"
#include "dos.h"

/*-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
   This program is a demonstration of the Digital Input/Output circuits.
   The program is a rendition of a security system, that allows you to
   monitor the status of 16 security sensors, and to automatically
   trigger four alarms that can be used to turn on the lights, activate
   a siren, or send a triggering pulse to a silent alarm.  The alarm system
   in this demonstration has four arming stations, which toggle the alarm on
   or off.

   LAST MODIFIED ON: SEPTEMBER 4, 1991
 -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-*/

int sensors_at_arm[15];
int sensors_now[15];             /*bit by bit status of sensors at current  */
                                 /*time.  When compared against status of   */
                                 /*sensors at arm, indicates break-in if    */
                                 /*there is a change.                       */
int arming_stations;             /*a variable representing all four arming  */
int old_arming_stations;         /*stations.  If value changes, toggle alarm*/
                                 /*ON / OFF.                                */

char key;   /*useful temporary variable*/
int i;      /*useful temporary variable used in loops*/
int j;      /*useful temporary variable*/

void initialize(){          /*this procedure sets MODE 0 as active,         */
  outportb(BASEADDR+3,0x93);/*and sets Port A, B, and C Lo as as input, with*/
/*outportb(addr,byte) is */ /*Port C Hi being output.                       */
/*C's method of accessing*/ /*the bit pattern required to set the desired   */
/*port memory.  The above*/ /*mode and port designations is 10010011=93 hex */
/*code sets port memory  */ /*Refer to the User Manual for a description of */
/*at 0x303 to 93 hex.    */ /*what each bit does.                           */
/*This address is the    */ /*-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=*/
/*IOD board's control */
/*register, assuming the base address is 300 hex.*/
} /*procedure initialize */

void read_sensors(int *ary){
unsigned char tempA;
unsigned char tempB;

  tempA = inportb(BASEADDR);
  tempB = inportb(BASEADDR+1);
  for(i=0;i<8;i++){
    if((tempA >> i) & ON){           /*this determinesif bit # i is ON  */
      *ary++=ON;}                    /*and sets the corresponding array */
    else{                            /*element to ON if it is ... else  */
      *ary++=OFF;}                   /*the array element is set to OFF. */
  }
  for(i=0;i<8;i++){
    if ((tempB >> i) & ON){
      *ary++=ON; }
    else{
      *ary++=OFF;}
  }
} /*procedure read_sensors*/

get_status(){
  int temp;
				   /*this sets status to the lower half */
  temp=inportb(BASEADDR+2);        /*(lower nybble) of Port C, the half*/
  return temp & 0x0F;              /*defined in Initialize to be input,*/
} /*function get_arming_status*/   /*for four (4) arming switches.     */

void ALARM(){
long int temp=0;

  sound(2000);                       /*this starts the computer's speaker */

  outportb(BASEADDR+2,0xF0);         /*this sets port C's upper nybble's  */
  do{                                /*bits to ON (1111 binary = F hex).  */
    arming_stations=get_status();    /*This activates four alarm outputs, */
    if (arming_stations != old_arming_stations)
       temp=2000000000;/*dis-armed*/ /*and then toggles port C Hi's LSB   */
    outportb(BASEADDR+2,inportb(BASEADDR+2) ^ 0x10);
  }while (temp++ < 200000000);      /*which might be used with an external*/
  nosound();                         /*speaker to produce a siren*/
} /*procedure ALARM*/

/*-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-*/
main()
{

time_t start;

  initialize();
  clrscr();
  gotoxy(5,5);
  printf("This is the IOD demonstration program.  This program will simulate\n");
  printf("an alarm system program, containing sixteen sensors and four arming\n");
  printf("stations, along with four separate alarm outputs, which could be routed\n");
  printf("to a siren, lights, silent alarm, etc. The base address should be\n");
  printf("set to 300 hex.\n");
  printf("\n");
  puts("  To arm the system, ground one of the arming stations (pins 9,11,13");
  puts("  or 15), when prompted to arm. To trigger an alarm, ground any odd");
  puts("  pin between 17 and 47, inclusive. To stop the alarm, either wait,");
  puts("  or ground an arming station again. To exit without triggering an ");
  puts("  alarm, ground an arming station. Then press a key when the prompt");
  puts("  appears. \n");

  printf("THIS PROGRAM IS INTENDED ONLY FOR DEMONSTRATION PURPOSES, AND IS NOT\n");
  printf("MEANT TO BE USED AS AN ACTUAL ALARM SYSTEM.\n");
  printf("\n");printf("\n");
  printf("Press any key to begin program.\n");
  key=getch();
  clrscr();
  puts("The program will now check for 'open' sensors. If any of the");
  puts("digital input lines is grounded, it will read as an open sensor.");
  puts("Make desired connections and press RETURN to continue.");

  old_arming_stations=get_status();
  do{
    read_sensors(sensors_now);
    for(i=0;i<=15;i++) {
      if (!sensors_now[i]) printf("Sensor #%d %s\n",i,"is open");
    }
    printf("\n");
    printf("Press ESC to re-scan, RETURN to begin alarm scanning.");
    key=getch();
    clrscr();
  }while(key!=13);
 for(;;){     /*this creates an infinite loop*/
  printf("Waiting to be armed, press any key halt program.\n");
  do{
    arming_stations=get_status();
    if (kbhit()) getch(),exit(0);
  }while(arming_stations == old_arming_stations);
  sound(1000);
  delay(300);
  nosound();
  printf("Alarm system will activate in 15 seconds");
  read_sensors(sensors_at_arm);
  old_arming_stations=get_status();
  start=time(NULL);
  do{
  }while(difftime(time(NULL),start) != 15);
  printf("\n");
  printf("ALARM SYSTEM ACTIVE AND ARMED\n\n");
  sound(900);
  delay(300);
  nosound();
  j=0;
  do{
    read_sensors(sensors_now);
    for(i=1;i<=15;i++) {
      if(sensors_now[i-1] != sensors_at_arm[i-1])
         j = i;
    } /*for*/
    arming_stations = get_status();
    if (arming_stations != old_arming_stations)
       j = -1;  /*flag used to signal alarm is de-activated*/
  }while(!j);
  if (j == -1) {
    start=time(NULL);
    printf("Alarm deactivated at %s",(asctime(gmtime(&start))));
    sound(900);
    delay(100);
    nosound();
    delay(50);
    sound(900);
    delay(100);
    nosound();
  }  else {
    printf("Sensor #%d has been activated!!\n\n",j);
    start=time(NULL);
    printf("The time of alarm is %s",asctime(gmtime(&start)));
    old_arming_stations=get_status();
    ALARM();
    delay(150);
  } /*else*/
 } /* for(;;)  this end is used to send program back to await re-arming*/
}