#ifndef _RS232_H
#define _RS232_H

#include<iostream.h>
#include<string.h>
#include<conio.h>


#define DLL 0 //divisor latch low byte 
#define DLH 1 //divisor latch high byte 
#define THR 0 //transmit hold register 
#define RBR 0 //recieve buffer register 
#define IER 1 //interrupt enable register 
#define LCR 3 //line control register 
#define MCR 4 // modem control register 
#define LSR 5 //line status register 
#define MSR 6 //modem status register 
#define RTS 0x02 // request to send 
#define CTS 0x10 //clear to send 
#define DTR 0x01 //data terminal ready 
#define DSR 0x20 //data set ready 
#define RBF 0x01 //bit 0 of LSR, rec buf full 
#define THRE 0x20 //bit 5 of LSR, trans reg 0 
#define DISINT 0x00 //disable interrupts in IER 
#define ABRG 0x83 //access baud rate generator 



class rs232
{
	public:
		rs232();
		rs232(int far*);
		
		
		void init(int,int,char*,int,int);
		void set_id(char [50]);
		void transmit(char,int);
		char receive(int);
		char rec(unsigned int);
		void send(unsigned int,int);
		void send_msg();
		void recv_msg();
		void listen();
		
	private:
		unsigned int divisorh, divisorl, format, acia[2], add;
		int val, comport,a;
		char byte, data, u_id[50], id[50];
		int far* bios;
		int com_port, baud_rate, word_size, stops;
		char *parity;
		char c[10];
};

rs232::rs232()
{


}

rs232::rs232(int far* bios)
{
	data=0;
	bios=(int far*)0x00400000l;
}

void rs232::send(unsigned int add, int val)
{
	_DX=add;
    _AL=val;
    asm out dx,al
}

char rs232::rec(unsigned int add)
{
    _DX=add;
    asm in al,dx
    return(_AL);
}

void rs232::set_id(char id[50])
{
	strcpy(u_id,id);
}
				
void rs232::init(int com_port,int baud_rate,char *parity,int stops, int word_size)
{
	acia[0]=*bios; 
	acia[1]=*(bios+1);
		
	send(acia[com_port]+IER, DISINT); 
	send(acia[com_port]+LCR, ABRG); 
	
	switch(baud_rate) 
	{
		case 300: 
		{
			divisorh = 01; 
			divisorl = 0x80; 
		}
		break;
		case 600: 
		{
			divisorh = 00; 
			divisorl = 0xc0; 
		}
		break;
		case 1200: 
		{
			divisorh = 00; 
			divisorl = 0x60;
		}
		break;
		case 2400: 
		{
			divisorh = 00; 
			divisorl = 0x30; 
		}
		break;
		case 4800: 
		{
			divisorh = 00; 
			divisorl = 0x18; 
		}	
		break;
		case 9600: 
		{
			divisorh = 00; 
			divisorl = 0x0c; 
		}
		break;
		default: 
		{
			cout<<"ERROR: INVALID BAUD RATE\n";
		}
	} 
	send(acia[com_port] + DLL, divisorl);
	send(acia[com_port] + DLH, divisorh);
	
	format = 0; 
	
	if((strcmp(parity,"E")==0) || (strcmp(parity,"O")==0)) 
	{
		format=format | 0x28; 
		if(strcmp(parity,"E")==0)
		{
			format=format | 0x10; 
		}
	}
	if(stops==2)
	{
		format=format|0x04;
		switch(word_size) 
		{
			case 8: 
			{
				format=format | 0x03; 
			}	
			break;
			case 7: 
			{
				format=format | 0x02; 
			}	
			break;
			case 6: 
			{
				format=format | 0x01; 
			}	
			break;
			case 5: 
			break;
			default: 
			{
				cout<<"ERROR: UNSUPPORTED WORD SIZE\n";
			}
		} 
		send(acia[com_port] + LCR, format);
	}
}
			
void rs232::transmit(char byte, int comport)
{
	send(acia[comport]+MCR, (RTS | DTR)); 
	
	while((rec(acia[comport]+LSR) & THRE)==0) 
				
	send(acia[comport]+THR, byte); 
	send(acia[comport]+MCR, 0);
}

char rs232::receive(int comport) 	
{
	send(acia[comport] + MSR, (RTS | DTR));
	
	while((rec(acia[comport]+LSR) & RBF)==0) 
			
	send(acia[comport] + MCR,0); 
	byte = rec(acia[comport] + RBR);
	return(byte);
}

void rs232::send_msg()
{	
	data=0;
	while(data < 50)
	{
		data=getch();
		cout<<data;
		transmit(data,0);
	}
}

void rs232::recv_msg()
{
	data=0;
	while((data!=50)&&(data!=0))
	{
		data=receive(0);
		cout<<data;
	}
}

#endif

#include"com.h"


int main()
{
	rs232 sock;
	
	sock.init(0,9600,0,1,8);
	
	sock.send_msg();
	
	return 0;
}