Ref: 17310017
Title: Configuring the Etherlink 16 for Performance
date: 12/27/90

Copyright 3Com Corporation, 1991.  All rights reserved.

The EtherLink 16 is a high performance, non-intelligent 16-bit adapter for
the ISA bus using shared memory.  It is self-sensing and can operate in
either 8- or 16-bit buses including standard ISA buses that operate at up
to 10 MHz.  Computers with selectable bus speeds must be set up within this
range.  This adapter comes with a 64 KB RAM buffer and Start PROM capability.
EISA bus operation is also supported.  As a result, this product is
ideal for 286, 386 and 486 PC servers as well as for netstations.

EISA configuration programs supplied by computer manufacturers cannot be used
to install the EtherLink 16 adapter since an adapter configuration file is not
available.  In order to configure the adapter in a computer with an EISA bus,
simply run the EISA config program without the adapter installed.  Then use
the 3C507 program to configure the adapter.  Make sure that there are no
device conflicts since the EISA configuration program is not being used to
automatically prevent conflicts.


A Net Management PROM contains the following information on the EtherLink 16:

  *  Ethernet Address           ( 00608C - Latest assigned 3Com prefix)
  *  Vendor Name                ("*3COM*")
  *  Adapter's 3Com part number
  *  Assembly Revision level

In addition to drivers for 3+ and 3+Open, the EtherLink 16 diagnostics
diskette contains drivers for Microsoft's LAN Manager (including 2.x) and
Novell's Netware 286 (2.15) and 386 (3.x) network operating systems.
A README file is included on the diskette for each network operating system
and provides installation instructions for the drivers.

Note:  The diagnostics diskette is provided only with individually packaged
3C507 adapters, not 5-packs.  An archived copy of the diskette is available
on the Ask3Com Forum in the Drivers libraries.


Adapter Configuration:

There are two settings that can be used to optimize the performance of the
EtherLink 16:  memory wait states, and shared memory buffer size.
Configuration parameters set by the 3C507.EXE diagnostics program are stored
in an EEPROM on the adapter.  Run 3C507.EXE only after booting from a
DOS-only boot disk that loads no drivers for network use.

*  For most high performance computers including Compaq 386 models, set
the adapter to the zero-wait-state setting.  To use this setting, the
host system must be able to support zero-wait-state accesses to the
adapter's 70 ns RAM.  This does NOT include the IBM AT or PS/2 Mod 30.

*  Where possible, use 64 KB of shared memory, but make sure that the buffer
address range assigned for adapter operation is not used by the system or
other boards.


Shared Memory Configuration:

Do not use a shared memory location that is assigned to system ROM, used
by system software, or used by other peripherals including video
adapters or SCSI/ESDI disk controllers.

The adapter's shared memory RAM window can be set to one of four
possible sizes:  64 KB, 48 KB, 32 KB, or 16 KB.  Best performance will be
obtained if the 64 KB window size can be used.  The window can be
configured to start at one of several possible PC memory addresses, as
defined below.

Standard RAM window base settings available:

    High DOS Addresses ( 16, 32, 48 or 64 K)
    -----------------------------------------------------
    0C0000   (Do not select if EGA or VGA display is in use!)
    0C8000
  * 0D0000   (Default setting)
    0D8000

Several Extended memory locations near the top of protected mode address
space can also be selected for the adapter's shared memory on systems
that use protected mode.  These buffer locations are addressable only by
protected-mode device drivers.  For these selections, adapter buffer size
must be 64KB; however, 128 KB of system memory address range is actually
allocated.  When examining the configuration for possible memory conflicts
with other allocations, calculate used buffer space using the 128 KB figure.

NDIS drivers running under the OS/2 operating system are the only known
drivers currently available that are capable of using these Extended
addresses.  Only 3+Open/LAN Manager servers and OS/2 netstations can use
this option.  If you use this option, make sure the computer is not configured
for system caching.  The Hewlett Packard Vectra 486 and some Compaq models
must have their system caching disabled to use this option.  (See the
computer's installation guide for instructions on disabling system caching.)

    Extended Memory Addresses
    -------------------------
    F00000
    F20000
    F40000
    F60000
    F80000


Configurations with 3COMEMM:

If using 3COMEMM, the configured memory address range for the EtherLink 16
must be protected, so it will not be used for high memory relocations.

High Performance:  If the EtherLink 16 is using a 64 KB window at
location 0D0000, use the following option statement for 3COMEMM:

    Device=3COMEMM.SYS RAM=D000-DFFF

Memory Conservation:  The EtherLink 16 can be set to use only a 16 KB
window on a DOS netstation.  One location that can be used is
address 0C8000.  This will provide adequate performance.  Most EGA,
VGA, or CGA display adapters do not have any ROM that uses this
location.  Use the following option statement for 3COMEMM:

    Device=3COMEMM.SYS RAM=C800-CC00

Refer to the EtherLink 16 Installation and Configuration Guide and the
README files on the diagnostics disk for more information.


