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

 unsigned char InitPrinter(int iPortNumber);
 unsigned char PrintCharacter(int iPortNumber,char cCharacter);
 unsigned char GetStatus(int iPortNumber);

 void ShowStatus(unsigned char ucStatus);

 int main( )
 {
    int iPortNumber=0;
    unsigned char ucStatus=0x00;
    char cEnglishAlphabet='A';

    clrscr( );

    ucStatus=InitPrinter(iPortNumber);
    ShowStatus(ucStatus);

    if((ucStatus&0x80)==0x80 && (ucStatus&0x10)==0x10)
    {
       printf("\nStarting Printing...\n\n");

       while(cEnglishAlphabet<='Z')
       {
      ucStatus=PrintCharacter(iPortNumber,cEnglishAlphabet);

      printf("%c",cEnglishAlphabet);

      cEnglishAlphabet++;
       }

       if(cEnglishAlphabet==91)
      printf("\n\nPrinting Completed.");

       else
       {
      printf("\nPrinting Terminated due to an Error\n");

      ShowStatus(ucStatus);
       }
    }

    getch( );
    return 0;
 }

 /*************************************************************************//*************************************************************************///------------------------  Funcion Definitions  ------------------------///*************************************************************************//*************************************************************************//*************************************************************************///-----------------------------  InitPrinter( )  ---------------------------///*************************************************************************/

 unsigned char InitPrinter(int iPortNumber)
 {
    union REGS InReg;
    union REGS OutReg;

    InReg.h.ah=0x01;
    InReg.x.dx=iPortNumber;

    int86(0x17,&InReg,&OutReg);

    return OutReg.h.ah;
 }

 /*************************************************************************///--------------------------  PrintCharacter( )  -------------------------///*************************************************************************/

 unsigned char PrintCharacter(int iPortNumber,char cCharacter)
 {
    union REGS InReg;
    union REGS OutReg;

    InReg.h.ah=0x00;
    InReg.h.al=cCharacter;
    InReg.x.dx=iPortNumber;

    int86(0x17,&InReg,&OutReg);

    return OutReg.h.ah;
 }

 /*************************************************************************///----------------------------  GetStatus( )  ---------------------------///*************************************************************************/

 unsigned char GetStatus(int iPortNumber)
 {
    union REGS InReg;
    union REGS OutReg;

    InReg.h.ah=0x02;
    InReg.x.dx=iPortNumber;

    int86(0x17,&InReg,&OutReg);

    return OutReg.h.ah;
 }

 /*************************************************************************///---------------------------  ShowStatus( )  ---------------------------///*************************************************************************/void ShowStatus(unsigned char ucStatus)
 {
    printf("Printer Status ::\n");

    if((ucStatus&0x80)==0x80)
       printf("- Printer Not Busy\n");

    if((ucStatus&0x40)==0x40)
       printf("- Acknowledgement from Printer\n");

    if((ucStatus&0x20)==0x20)
       printf("- Out of Paper\n");

    if((ucStatus&0x10)==0x10)
       printf("- Printer Selected\n");

    if((ucStatus&0x08)==0x08)
       printf("- I/O Error\n");

    if((ucStatus&0x01)==0x01)
       printf("- Time-Out Error\n");
 }