Learning C Functions : biosprint ( Dos Only )

C Programming :
Function : biosprint

Example    Portability

Syntax

#include <bios.h>
int biosprint(int cmd, int abyte, int port);

Description

biosprint performs various printer functions on the printer identified by the parameter port using BIOS interrupt 0x17.
A port value of 0 corresponds to LPT1; a port value of 1 corresponds to LPT2; and so on.
The value of cmd can be one of the following:

0    Prints the character in abyte.
1    Initializes the printer port.
2    Reads the printer status.

The value of abyte can be 0 to 255.

Return Value

The value returned from any of these operations is the current printer status, which is obtained by ORing these bit values together:

Bit 0    0x01    Device time out
Bit 3    0x08     I/O error
Bit 4    0x10     Selected
Bit 5    0x20     Out of paper
Bit 6    0x40     Acknowledge
Bit 7    0x80     Not busy

Example :
/* biosprint example */

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

int main(void)
{
   #define STATUS  2    /* printer status command */
   #define PORTNUM 0    /* port number for LPT1 */

   int status, abyte=0;

   printf("Please turn off your printer. Press any key to continue\n");
   getch();
   status = biosprint(STATUS, abyte, PORTNUM);
   if (status & 0x01)
      printf("Device time out.\n");
   if (status & 0x08)
      printf("I/O error.\n");

   if (status & 0x10)
      printf("Selected.\n");
   if (status & 0x20)
      printf("Out of paper.\n");

   if (status & 0x40)
      printf("Acknowledge.\n");
   if (status & 0x80)
      printf("Not busy.\n");

   return 0;
}