Ref: 99980139
Title: T0ASYN PROM Revision 18C
Date: 7/2/87

Copyright 3Com Corporation, 1991.  All rights reserved.

Enclosed is a set of T0ASYN Revision 18C PROMs for the CS/100
asynchronous board.  This set consists of one Revision 18C PROM
from bit 0 to bit 7 and one Revision 18C PROM from bit 8 to bit
F.

.h1;Installation

To install the Revision 18C PROMs on the CS/100 asynchronous
board, follow these steps:

1.  If the rows of pins are too far apart to fit into the
sockets, press them closer together by pushing one row of pins
against a flat surface.

2.  On the CS/100 asynchronous board, gently push the PROM marked
0-7 into the socket marked 0-7.  Then gently push the PROM marked
8-F into the socket marked 8-F.  Be sure that the notch in each
PROM is oriented in the same direction as the corresponding notch
in the currently installed set of PROMs.

.h1;New Features

The following features, which were not present in T0ASYN Revision
17F or earlier, have been implemented in T0ASYN Revision 18C:

1.  It now supports eight-bit data transfer plus parity checking.
The parity can be odd, even, or none.

2.  The ECM character can be sent both in band and out of band.

3.  After you have set the BAud parameter to LowAutoBaud, your
terminal's baud rate can be set to 300, 600, 1200, or 2400.
If the BAud parameter is set to HiAutoBaud, your terminal's
baud rate can be set to 2400, 4800, 9600, or 19200.

.h1;Bugs Fixed

The following problems, which were present in T0ASYN Revision 17F
or earlier, have been corrected in T0ASYN Revision 18C:

1.  The CS/100 now works properly when a long break is received.

2.  The ^Q character, which is the XON character, can be embedded
in terminal responses.  In the past, the first XON character in a
character stream was recognized as a flow control character, and
any subsequent XON character would be passed to the host as data.
Now the extra XON characters are stripped before the character
stream is sent to the host.

3.  A long break is no longer lost when DTR drops.

4.  When the UseDCDout parameter is set to ToggleonDisc, the DCD
output signal will be deasserted after disconnection for at least
approximately 250 milliseconds instead of 100 milliseconds.

5.  The ENQ/ACK flow control options, which were never supported
by the M0ASYNC firmware, have been eliminated.

.h1;Miscellaneous

To avoid being invoiced for the new PROM sets, return the old set
to 3Com within 30 days.

If you have any questions, please contact an authorized 3Com
service representative for assistance.
