3Com Corporation
                EtherDisk Diskette for the EtherLink II Family
                   Diagnostic Program Instructions Summary



  Overview
  --------

  The diagnostic program for the EtherLink II adapter is designed to make sure
  the adapter is installed correctly and functioning properly in your 
  computer.  The Group 1 tests check the physical components, connectors, and 
  circuitry of the adapter and require only that the adapter be installed in 
  the computer.  The Group 2 tests check the adapter's ability to transmit 
  data on the network and require that the adapter be connected to a loopback 
  plug (coax version only) or to a network.  The Group 3 tests check the 
  adapter's ability to correctly transmit and receive data over the network 
  and require that the adapter be connected to a network on which an echo 
  server has been set up.


  Starting the Diagnostic Program
  -------------------------------

  The computer containing the EtherLink II adapter to be tested must be 
  running DOS.  

  NOTE:  If this computer is an operating server, notify all users of the 
         server to save their work and log out from the network.  The 
         diagnostic program disrupts the normal operation of servers, and 
         workstations, so work that is not saved may be lost.  

  There are two ways to start the diagnostic program:

  1.  Automatically from the "MENU.BAT" program, by selecting the options in 
      the Diagnostics submenu.

  2.  Manually, from the root directory of the Etherdisk diskette by typing
      the following command:
  
      3C503 [/B:I/O BASE ADDRESS] [/S]

      The brackets indicate that the /B and /S switches are optional.

      If the /B switch is omitted, the diagnostic program will search through 
      the possible I/O base addresses to find an EtherLink II adapter to test.
      Use the /B switch to specify a particular EtherLink II adapter to be 
      tested in a computer with multiple EtherLink II adapters installed.  
      Enter the I/O base address of the adapter to be tested for I/O BASE 
      ADDRESS.

      If the /S switch is specified, the diagnostic program will test DMA
      transfers	using the single-byte mode.  If the switch is omitted, DMA
      demand mode is used.


  Using the Diagnostic Program
  ----------------------------
  While using the diagnostic program, you will be asked to specify a DMA
  channel, interrupt level, and transceiver type.  Select a DMA channel and
  interrupt level that do not conflict with any other peripherals installed in
  the computer.  See the SYSRESRC.TXT file in the \INFO directory on the
  EtherDisk diskette for a list of system resources used by other common
  peripherals. The ON-BOARD transceiver (BNC or RJ45 connector) is the 
  default setting.  EXTERNAL should be selected if an external transceiver 
  (AUI connector) is being used.

  The menus and forms that make up the diagnostic program will guide you
  through testing your EtherLink II adapter.  The following keys can be used:

     Key              Function
     ---              --------

     [Up-arrow]       Moves highlight within menus and forms
     [Down-arrow]

     [Enter]          Selects highlighted item
     [Return]

     [F1]             Gives help information about the highlighted item

     [Esc]            Returns to previous menu or form
                      Stops a test
                      Stops echo server operation


  If the adapter fails the diagnostic program, see the TROUBLE.TXT file in the
  \DIAG directory on the EtherDisk diskette for troubleshooting procedures.


  Further Information
  -------------------

  For more information about the diagnostic program and how to use it,        
  refer to the appropriate adapter guide.  The SUPPORT.TXT file in the
  \INFO subdirectory on the EtherDisk diskette provides information about
  obtaining product support for the EtherLink II adapter.  For more 
  information about jumper settings for the twisted-pair adapters, refer to 
  the TPOPTS.TXT file, in the \INFO subdirectory.

  The TROUBLE.TXT, SUPPORT.TXT , and TPOPTS.TXT files can be automatically 
  displayed and printed from the "MENU.BAT" program.


(%VER  Diagnostic Program Instructions Summary v2.0b)