#include <stdio.h>
#include <dos.h>
#define PRINTER 0x17	//BIOS printer port
#define LPT1 0x00		//LPT1, your first printer
#define EJECT 0x0c		//Eject page printer command

void prnstring(char *string);
void eject(void);
void prnchar(char c);

void main()
{
	printf("Please ensure that your printer is on and ready to print.\n");
	printf("Press Enter:");
	getch();

	prnstring("Testing.\r\n");
	prnstring("Hey! It works!");
	eject();
}

void prnstring(char *string)
{
	while(*string)				//while there is a character to print
		prnchar(*string++);		//print it and increment
}

void eject(void)
{
	prnchar(EJECT);
}

void prnchar(char c)
{
	union REGS regs;

	regs.h.ah=0x00;		//print character function
	regs.h.al=c;		//character to print
	regs.x.dx=LPT1;		//printer port to print to
	int86(PRINTER,&regs,&regs);
}