Ref: 02880053
Title: IBM Token, Intel AboveBoard, and EGA/Lotus in AT
Date:  08/08/88

Copyright 3Com Corporation, 1991.  All rights reserved.

QUESTION:  How do you make an IBM Token Ring board work in the
same machine as an Intel AboveBoard and run EGA graphics such as
Lotus under 3+ on an AT machine?

ANSWER:  The Intel AboveBoard uses a 64KB block of memory between
the 640KB DOS limit and 1MB.  The IBM Token Ring Adapter also
uses an 8KB block of memory in that same range.  You need to
make sure that you configure the boards so that they don't try to
use the same area, which they do by default.

The Intel AboveBoard can be configured by editing the config.sys
file.  The line "DEVICE=EMM.SYS Mz ..." determines what 64KB
block of RAM to use.  If you replace "Mz" with "M5" (the default)
then the board will use the 64KB beginning at address D0000.

The IBM Token board is configured via two "switch blocks".  The
one on the right, switch block one, contains eight switches.  The
first six of those determine the address of the 8KB block needed
by the board.  Appendix B of the Guide to Operations (it comes
with the board) lists all the available 8KB locations.  Just pick
one that is not in conflict with the Intel board.  A good
location to use is A0000 which lies immediately after the 640KB
DOS limit.  To select this location on switch block one, set
switch two off.  Switch one and three through six should be set
on (SW1= 10110011).  EGA graphics occupy A0000 through BE000.

Synopsis

To make them work together do the following:

1. For the Intel board edit config.sys to read

    DEVICE = EMM.SYS M5 ...

2. On switch block one of the IBM board set switchs one through
six on, except for switch two which should be off.  (2/87)

Note:  If switch settings are incorrect, the system will boot
fine and pass the runminds statement fine, but will give a post
monitor error (1 long and 2 or 3 short beeps.)  If the system
beeps even once during boot, graphics will fail, though 3+ will
work fine otherwise.
