package parport;public class ParallelPort {   /** The port base address (e.g. 0x378 is base address for LPT1) */   private int portBase;   /** To cunstruct a ParallelPort object,     * you need the port base address   */   public ParallelPort (int portBase)   {      this.portBase = portBase;   }   /** Reads one byte from the STATUS pins of the parallel port.     *     * The byte read contains 5 valid bits, corresponing to 5 pins of input     * from the STATUS pins of the parallel port (the STATUS is located     * at "portBase + 1", e.g. the STATUS address for LPT1 is 0x379).     *     * This diagram shows the content of the byte:     *     *  Bit | Pin # | Printer Status  | Inverted     * -----+-------+-----------------+-----------     *   7  |  ~11  | Busy            |   Yes     *   6  |   10  | Acknowledge     |     *   5  |   12  | Out of paper    |     *   4  |   13  | Selected        |     *   3  |   15  | I/O error       |     *     * Note that Pin 11 is inverted, this means that "Hi" input on pin     * means 0 on bit 7, "Low" input on pin means 1 on bit 7.   */   public int read ()   {      return ParallelPort.readOneByte (this.portBase+1);   }   /** Writes one byte to the DATA pins of parallel port.     * The byte is written to the DATA pins of the port. The DATA pins are     * located at the base address of the port (e.g. DATA address for LPT1     * is 0x378).     *     * This diagram shows how the byte is written:     *     *  Bit | Pin # | Printer DATA     * -----+-------+--------------     *   7  |   9   |   DATA 7     *   6  |   8   |   DATA 6     *   5  |   7   |   DATA 5     *   4  |   6   |   DATA 4     *   3  |   5   |   DATA 3     *   2  |   4   |   DATA 2     *   1  |   3   |   DATA 1     *   0  |   2   |   DATA 0   */   public void write (int oneByte)   {      ParallelPort.writeOneByte (this.portBase, oneByte);   }   /** Reads one byte from the specified address.     * (normally the address is the STATUS pins of the port)     */   public static native int readOneByte (int address);   /** Writes one byte to the specified address     * (normally the address is the DATA pins of the port)     */   public static native void writeOneByte (int address, int oneByte);   static   {      System.loadLibrary("parport");   }}