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

#define uint unsigned int

#ifdef __cplusplus
   #define __CPPARGS ...
#else
   #define __CPPARGS
#endif

unsigned int IRQ = 5;

int IRQGenerated = 0;
uint BASE=0x300;

void sendEOI(void)
{
   //send non-specific to master AND slave PIC
   outportb(0x20, 0x20);
   outportb(0xA0, 0x20);
}

void  interrupt far (*oldirq[16])(__CPPARGS);


unsigned char initirq(char IRQnumber,void interrupt (*ISR)())
{
   unsigned char intmask, oldmask;

   if (IRQnumber <=7) {
      oldmask = inportb(0x21);
      oldirq[IRQnumber] = getvect(IRQnumber + 8);
      setvect(IRQnumber + 8,ISR);
      intmask = oldmask & (~(1 << IRQnumber));
      outportb(0x21,intmask);
   } else {
      oldmask = inportb(0xA1);
      oldirq[IRQnumber] = getvect(IRQnumber + 0x70 - 8);
      setvect(IRQnumber - 8 + 0x70, ISR);
      intmask = oldmask & (~(1 << (IRQnumber - 8)));
      outportb(0xA1, intmask);
   }
   return(oldmask);
}

void restoreirq(char IRQnumber)
{
   unsigned char intmask;

   if (IRQnumber <=7 ){
      intmask = inportb(0x21);
      intmask |= (1 << IRQnumber);
      setvect(IRQnumber + 8, oldirq[IRQnumber]);
      outportb(0x21, intmask);
   } else {
      intmask = inportb(0xA1);
      intmask |= (1 << (IRQnumber - 8));
      setvect(IRQnumber - 8 + 0x70, oldirq[IRQnumber]);
      outportb(0xA1, intmask);
   }
}

void CtrMode(uint addr, char cntr, char mode)
{
  int ctrl;
  ctrl = (cntr << 6) | 0x30 | (mode << 1);
  outportb(addr+3,ctrl);
}

void CtrLoad(uint addr ,int c,int val)
{
  outportb(addr+c,val & 0x00FF);
  outportb(addr+c,(val>>8) & 0x00FF);
}

uint CtrRead(uint addr , int c)
{
  outportb(addr+3,c<<6);
  return inportb (addr+c) + (inportb(addr+c) << 8);
}

unsigned AskForBaseAddress(unsigned int OldOne)
{
	char msg[7];
	int NewOne = 0, Success = 0, Dummy;
	int AddrInputPosX, AddrInputPosY;

	puts("Please enter the Base Address for your card (in hex)");
	printf("or press ENTER for %X.\n>", OldOne);
	AddrInputPosX = wherex(); AddrInputPosY = wherey();
	do {
		gotoxy(AddrInputPosX, AddrInputPosY);
		clreol();
		msg[0] = 5; msg[1] = 0;
		cgets(msg);
		sscanf(msg + 2, "%x", &NewOne);
		Success = 1;
		Dummy = NewOne;
		if (msg[1] == 0) {
			gotoxy(AddrInputPosX, AddrInputPosY);
			printf("%X", OldOne);
			Success = 1;
			Dummy = OldOne;
		}
	} while(!Success);
	return (Dummy);
} /* end of AskForBaseAddress */

void interrupt ADC_interrupt()
{
   IRQGenerated = 1;
   inp(BASE+1);
   outp(0x20,0x20);                                    // reset PIC
}

void main(void) {
  int data;
  int chan=0;

  clrscr();

  puts("Sample 7\n");
  puts("This sample will read data from all channels on the A/D board using\n"
       "timer/counter #2 to time and start conversions.  End of conversion\n"
       "will be detected by IRQ generation.");
  puts("Card MUST be set at IRQ5.");
  puts("All other jumper settings are irrelevant.");


  BASE=AskForBaseAddress(BASE);

  initirq(IRQ, ADC_interrupt);
  CtrMode(BASE+12,0,2);//all counters in mode 2
  CtrMode(BASE+12,1,2);//all counters in mode 2
  CtrMode(BASE+12,2,2);//all counters in mode 2
  //counter zero without count, it won't increment, cause we don't need it.
  CtrLoad(BASE+12,1,0x00F);
  CtrLoad(BASE+12,2,0x00F);
  outportb(BASE+2,chan);//setup channel and gain (gain code 0, gain of 1)
  outportb(BASE+0,0xEA);//allow counter to start conversions
  inportb(BASE+1);//clear existing interrupts

  while(!kbhit()){
    while ((!IRQGenerated) && (!kbhit()));
    IRQGenerated = 0;
    data=(inport(BASE+6)>>4) & 0x0FFF; //read data from conversion
    gotoxy(10,12+chan);
    printf("Channel: %i  Data Read: %4x",chan,data);
    chan++;
    chan%=8;
    outportb(BASE+2,chan);//setup next channel
  }
  getch();
  gotoxy(1,20);
  outportb(BASE+0,0x00);//turn off IRQs and counters
  restoreirq(IRQ);
}