BNC cabling specifications
                                                                    v1.00


Specifications and recommendations for Thin Ethernet cable
==========================================================

Certain models of the EtherExpress(TM) 10 ISA adapters have a
cylindrical, bayonet BNC connector.

BNC cabling is also known as thin Ethernet, RG-58A/U, Cheapernet, and
10BASE-2.

This document contains cabling and installation recommendations.  For
more information on thin Ethernet cabling, contact your local network
supplier or call the IEEE at 1-800-678-IEEE.


Recommended cables
------------------

Here is a list of IEEE approved and non-approved cables.

Approved cable types
------------------------------------------------
      802.3 10Base2     50 ohms, stranded tinned core
      RG-58 a/u         50 ohms, stranded tinned core
      RG-58 c/u         50 ohms, stranded tinned core
------------------------------------------------

Non-Approved cable types
------------------------------------------------
      RG-58             50 ohms, solid center core
      RG-58 u           50 ohms, solid center core
------------------------------------------------

Installation recommendations
----------------------------

Thin Ethernet is a linear bus topology that uses a COAX cable.  A break
in the cable will disrupt the entire segment.  Each node is connected to
the cable using a T-connector.

Warning: Don't connect the end of the cable directly to the BNC connector
         on the EtherExpress adapter.

Both ends of a trunk must be terminated with 50 ohm terminators.  One end
should be grounded.

Up to 5 trunk segments can be connected (through repeaters), but only 3
of these segments can have workstations attached.  Repeaters count as a
workstation so if you have two repeaters on a segment, the maximum number
of user workstations is 28.

Example:
                     no workstations               no workstations
                            |                             |
                            v                             v
      |--+--------+  +--------+  +------+-------+  +-------+  +----+----|
      |           |  |        |  |      |       |  |       |  |    |
      |         repeater     repeater   |     repeater   repeater  |
      |                                 |                          |
      workstation                   workstation              workstation
         1-29                          1-28                       1-29

Cable lengths
------------------------------------------------------------------
      Max trunk length                185 meters (607 feet)
      Max number of nodes per trunk    30
      Max number of trunks              5 (only 3 can have wkst.
      attached)
      Max length of entire network    925 meters (3035 feet)
         (all trunks added together)
      Min cable length between nodes   .5 meters (1 1/2 feet)
------------------------------------------------------------------