procedure printer_stat;
type str4 = string[4];
const PaperEnd_Bit=   5;  {port_addr    }
      SLCT_Bit    =   4;  {port_addr    }
      ACK_Bit     =   6;  {port_addr    }
      Busy_Bit    =   7;  {port_addr    }
      Strobe_Bit  =   0;  {port_addr +1 }
      AutoFeed_Bit=   1;  {port_addr +1 }
      INIT_Bit    =   2;  {port_addr +1 }
      SLCTIN_Bit  =   3;  {port_addr +1 }

  var ch          : char;
      port_addr   : integer;

  function hex_str(w: integer): str4;
   const hex: array[0..15] of char =('0','1','2','3','4','5','6','7','8',
                                     '9','A','B','C','D','E','F');
  var hex_str_temp: str4;
   begin
    hex_str_temp := '0000';
    hex_str_temp[4] := hex[(w and 15)];
    w := w shr 4;
    hex_str_temp[3] := hex[(w and 15)];
    w := w shr 4;
    hex_str_temp[2] := hex[(w and 15)];
    w := w shr 4;
    hex_str_temp[1] := hex[(w and 15)];
    hex_str := hex_str_temp
  end;

begin {printer_stat}
  clrscr;
  writeln('Press any key to stop display.');
  window(1,3,80,25);
  repeat
    gotoxy(1,1);
    port_addr := memw[$40:08];
    if port_addr  > 270 then begin
      write('LPT @ ',hex_str(port_addr),' ');
      port[port_addr] := $FF;
      port[port_addr+2]:= 0;
      writeln('Busy Line     : '           , not odd(port[port_addr +1] shr   7):5);
      writeln('           ACK Line      : ', not odd(port[port_addr +1] shr   6):5);
      writeln('           Paper End Line: ', odd(port[port_addr +1] shr   5):5);
      writeln('           SLCT Line     : ', odd(port[port_addr +1] shr   4):5);
      writeln('           ERROR Line    : ', not odd(port[port_addr +1] shr   3):5);
      writeln('           SLCTIN Line   : ', not odd(port[port_addr +2] shr   3):5);
      writeln('           INIT Line     : ', odd(port[port_addr +2] shr   2):5);
      writeln('           Auto Feed Line: ',  odd(port[port_addr +2] shr   1):5);
      writeln('           Strobe Line   : ',  odd(port[port_addr +2        ]):5);
    end;
    port_addr := memw[$40:$A];
    if port_addr  > 270 then begin
      writeln;
      writeln('LPT @ ',hex_str(port_addr),' status of the status lines: ');
      port[port_addr] := $FF;
      writeln('Busy Line     : ', odd(port[port_addr +1] div 128):5);
      writeln('ACK Line      : ', odd(port[port_addr +1] div  64):5);
      writeln('Paper End Line: ', odd(port[port_addr +1] div  32):5);
      writeln('SLCT Line     : ', odd(port[port_addr +1] div  16):5);
      writeln('SLCTIN Line   : ', odd(port[port_addr +2] div   8):5);
      writeln('INIT Line     : ', odd(port[port_addr +2] div   4):5);
      writeln('Auto Feed Line: ', odd(port[port_addr +2] div   2):5);
      writeln('Strobe Line   : ', odd(port[port_addr +2        ]):5);
    end;
    port_addr := memw[$40:$C];
    if port_addr  > 270 then begin
      writeln;
      writeln('LPT @ ',hex_str(port_addr),' status of the status lines: ');
      port[port_addr] := $FF;
      writeln('Busy Line     : ', odd(port[port_addr +1] div 128):5);
      writeln('ACK Line      : ', odd(port[port_addr +1] div  64):5);
      writeln('Paper End Line: ', odd(port[port_addr +1] div  32):5);
      writeln('SLCT Line     : ', odd(port[port_addr +1] div  16):5);
      writeln('SLCTIN Line   : ', odd(port[port_addr +2] div   8):5);
      writeln('INIT Line     : ', odd(port[port_addr +2] div   4):5);
      writeln('Auto Feed Line: ', odd(port[port_addr +2] div   2):5);
      writeln('Strobe Line   : ', odd(port[port_addr +2        ]):5);
    end;
    delay(300);
  until keypressed;
  read(kbd,ch);
  end;{ printer stat}

  var target: file;
begin
  printer_stat;
  assign(target,'run.chn');
  chain(target)
end.