U.S. ROBOTICS, INC.
===================

   MICRO LINK 300

   Card Type                Modem (asynchronous)                  
   Chip Set                 U.S. Robotics                         
   Maximum Data Rate        300bps                                
   Data Bus                 External                              
   Data Modulation Protocol Bell 103/113                          

                                                            V2251

   +------------------------------------------------------------+
   |                        CONNECTIONS                         |
   |------------------------------------------------------------|
   |     Function      |   Label    |    Function    |  Label   |
   |------------------------------------------------------------|
   | Line out/in - unidentified |   CN1   | DC power      | CN4 |
   |----------------------------+---------+---------------+-----|
   | Line in/out - unidentified |   CN2   | Power switch  | SW1 |
   |----------------------------+---------+---------------+-----|
   | RS-232/422                 |   CN3   | Analog        | SW2 |
   |                            |         | loopback      |     |
   |                            |         | switch        |     |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                           RS232C                           |
   |------------------------------------------------------------|
   |         Setting          | SW3/A  | SW3/B  | SW3/C | SW3/D |
   |--------------------------+--------+--------+-------+-------|
   | Pin 2 receive/Pin 3 send |   On   |   On   |  Off  |  Off  |
   |--------------------------+--------+--------+-------+-------|
   | Pin 2 send/Pin 3 receive |  Off   |  Off   |  On   |  On   |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                     DIAGNOSTIC LED(S)                      |
   |------------------------------------------------------------|
   | LED | Color | Status |              Condition              |
   |-----+-------+--------+-------------------------------------|
   | CD  |  Red  |   On   |       Carrier signal detected       |
   |-----+-------+--------+-------------------------------------|
   | CD  |  Red  |  Off   |     Carrier signal not detected     |
   |-----+-------+--------+-------------------------------------|
   | ON  |  Red  |   On   |             Power is on             |
   |-----+-------+--------+-------------------------------------|
   | ON  |  Red  |  Off   |            Power is off             |
   |-----+-------+--------+-------------------------------------|
   | AL  |  Red  |   On   |  Modem is in analog loopback test   |
   |     |       |        |                mode                 |
   |-----+-------+--------+-------------------------------------|
   | AL  |  Red  |  Off   |   Modem is not in analog loopback   |
   |     |       |        |              test mode              |
   |-----+-------+--------+-------------------------------------|
   | SD  |  Red  |   On   |     Modem is transmitting data      |
   |-----+-------+--------+-------------------------------------|
   | SD  |  Red  |  Off   |   Modem is not transmitting data    |
   |-----+-------+--------+-------------------------------------|
   | RD  |  Red  |   On   |       Modem is receiving data       |
   |-----+-------+--------+-------------------------------------|
   | RD  |  Red  |  Off   |     Modem is not receiving data     |
   +------------------------------------------------------------+

   +-------------------------------+
   | MISCELLANEOUS TECHNICAL NOTES |
   |-------------------------------|
   | Note: Diagram not available.  |