HPUX cent[7]

 cent(7)                                                             cent(7)





 NAME
      cent - Centronics-compatible interface

    REMARKS
      This manual entry applies only to peripherals connected to the cent
      interfaces found on Series 300, 400, and 700 systems.

 DESCRIPTION
      cent is a simple, widely used communication protocol most commonly
      associated with printers, plotters and scanners.  It is an eight-bit
      parallel data interface with additional control signals from the host
      computer, and status signals from the peripheral.

      The model for the cent interface drivers is simple in that no
      character processing is done; i.e., no interpretation is applied to
      the data being transferred between computer and peripheral.
      Therefore, all bytes sent to or received from a device are handled
      without alteration.  In other words, the cent interface drivers always
      operate in raw mode which means that any desired data interpretation
      must be performed by a user program (such as the lp spooler in
      conjunction with an appropriate model file).

 DEPENDENCIES
    Series 300/400
      A wide variety of control functions are supported.  See Device I/O
      Library (gpio*(3I), hpib*(3I), and io*(3I)), entries in Section 3 of
      this manual.

    Series 700
      The Series 700 cent driver supports six different handshake modes for
      data transfer.  The last four bits of the minor number of the device
      special file specify which mode is used.  The format of the device
      minor number is:

           0xSEF00A

      where each letter represents a single hexadecimal digit as follows:

      0x   Preamble to a hexadecimal number.

      S    Specifies the system bus module number ( 2 for core I/O).

      E    Specifies the EISA slot number: ( always 0 for core I/O).

      F    Specifies the function number.  Always 6 for the Core I/O
           parallel interface.

      00   Always 0.

      A    Specifies the handshake mode.  The handshake modes are:




 Hewlett-Packard Company            - 1 -     HP-UX Release 9.0: August 1992






 cent(7)                                                             cent(7)





                mode 1    Automatic handshaking using both nACK and BUSY.
                          Minor number format: 0xSEF001.

                mode 2    Automatic handshaking using only BUSY.  Minor
                          number format: 0xSEF002.

                mode 3    Bidirectional read/write used for ScanJet.  Minor
                          number format: 0xSEF003.

                mode 4    Stream mode.  Data is essentially transmitted to
                          the peripheral without any handshaking protocol.
                          Minor number format: 0xSEF004.

                mode 5    Pulsed mode using both ACK and BUSY for automatic
                          handshaking.  Similar to mode 1 except that the
                          data strobe line, nSTROBE is pulsed for a fixed
                          amount of time by the sender, then released.
                          Minor number format: 0xSEF005.

                mode 6    Pulsed mode, using only BUSY for automatic
                          handshaking.  Similar to mode 1 except that the
                          data strobe line, nSTROBE is pulsed for a fixed
                          amount of time by the sender, then released.
                          Minor number format: 0xSEF005.

           Modes 1 and 2 support most printers belonging to the *Jet series
           (LaserJet, DeskJet, QuietJet, etc.).

 AUTHOR
      cent was developed by HP.

 SEE ALSO
      lp(1), ioctl(2), intro(7), lp(7).

      System Adminstrator manuals included with your system.



















 Hewlett-Packard Company            - 2 -     HP-UX Release 9.0: August 1992