// a very short delay
void shortdelay(unsigned long interval);

unsigned short __far *parallelbase = (unsigned short __far*)0x00400008L;

// returns 0 if everything is ok
// returns 1 if there is no such parallel port
char parallel_init(unsigned short port, unsigned int mode)
{
  unsigned short control_port = parallelbase[port]+2;

  if(!parallelbase[port])
    return 1;

    // disable interrupts
    outbyte(control_port, inbyte(control_port) & ~0x10);   
 
    // reset the device and select the device and set direction to write   
    outbyte(control_port, inbyte(control_port) & ~(0x04 | 0x20));
    delay(50);
    outbyte(control_port, inbyte(control_port) | 0x04 | 0x08);

//    if mode is !0, switch auto line feed on (BIOS call does not do this!!)
    if(mode & 0x00FF)
      outbyte(control_port, inbyte(control_port) | 0x02);

    delay(1000);

  return 0;
}

// returns 0 if everything is OK
// returns 1 if a non-critical error happened (out of paper or something)
// returns 2 if a critical error happened
unsigned char parallel_write(unsigned short port, unsigned char chr)
{
  unsigned char retval;
  unsigned short control_port = parallelbase[port]+2;
  unsigned short printer_port = parallelbase[port];
  unsigned short status_port = parallelbase[port]+1;
  unsigned short retries = 0;


  if(inbyte(status_port) & 0x20)
    return 1;

  outbyte(printer_port, chr);

  // this check and delay is essential - otherwise things happen too fast!!!
  while(!(inbyte(status_port) & 0x80) && ++retries)
    shortdelay(LPT_PULSE_DELAY);

  retries = 0;

  shortdelay(LPT_PULSE_DELAY);

  outbyte(control_port, 0x0D);

  shortdelay(LPT_PULSE_DELAY);

  outbyte(control_port, 0x0C);

  inbyte(status_port);

  while(!(inbyte(status_port) & 0x80) && ++retries)
    shortdelay(LPT_PULSE_DELAY);

  if(!(inbyte(status_port) & 0x08))
    return 2;

  return 0;
 
}