Dec 092017
Windows 3.0 utility that displays UART Status. (Lights for Modem).
File WUARTMO.ZIP from The Programmer’s Corner in
Category Windows 3.X Files
Windows 3.0 utility that displays UART Status. (Lights for Modem).
File Name File Size Zip Size Zip Type
UARTMON.DOC 4076 1714 deflated
UARTMON.EXE 24160 13104 deflated

Download File WUARTMO.ZIP Here

Contents of the UARTMON.DOC file


Version 1.2
Feb. 18, 1991

For monitoring installed serial ports.

Copyright 1991 Unitech Associates, Inc.
P.O. Box 566
Newark, Delaware 19715

AUTHOR: Dale S. Hoover (CIS 73300,3712)


This program is designed to monitor the UARTS associated with
serial ports ( COM1-COM4 ). It is intended to be use simultaneous
with an application using the UART. It should not interfere in the
monitoring mode although the menus allow the end user to change the
baud rate, data_bits, stop_bits, and parity. Certain combinations
of data_bits, stop_bits, and parity are not valid and are inhibited
in the menus. Because the intended use is to monitor the serial port
the serial ports are not opened and the interrupts of are not
modified, tested, or chained. If no application is using the UART
then the monitor will not reflect valid information ( i.e. the UART
needs to be initialized by an application other than the monitor. )


In the BIOS DATA AREA of system memory there is a list of serial
port addresses in the 4 words beginning at 0000:0400. Most systems
use the default 3F8 for COM1 and 2F8 for COM2. There is no
standard for COM3 and COM4, so you need to make sure the BIOS
DATA AREA correctly reflects the right addresses for COM3 and
COM4 if your machine has these ports. Windows uses default
addresses as listsed below but these can be altered using the
COMxBase=XXXh directive in the SYSTEM.INI file. ( see SYSINI2.TXT
in you {WINDOWS} directory).

Default Windows 3.0 : Changed using :

COM1=3F8h COM1Base = xxxh;
COM2=2F8h COM2Base = xxxh;
COM3=2E8h COM3Base = xxxh;
COM4=2E0h COM4Base = xxxh;

If you encounter any problems with accessing serial ports it would
be a good idea to verify the addresses stored in the BIOS DATA AREA.
This can be accomplished using the "Ports" menu. There is an option
IO_Address which shows the IO_Address as determined from WINDOWS
default setting or values that are read from the BIOS. If a COMx
address shows "default" as the source then the BIOS does not know
the address. It is still possible that software (including WINDOWS
APPS...) can function if it is written to bypass the BIOS DATA AREA
values for the UART IO address. If a COMx address shows the source
as bios then the value for that port was determined from a read of

Once the IO address is known for a given UART it is a simple task
to investigate the UART registers to determine the status of the
various RS232 lines. The monitor gets a WM_TIMER message every
200 msecs and update the screen with any changes in the UART

As a utility this can be very useful when first connecting
a new serial device. Basically this is a WINDOWS "BREAKOUT Box".


Just run it and read the results.


UARTMON.EXE and this document are provided free by Unitech
Associates, Inc., Newark, Delaware. They may be copied and
distributed provided no money is charged for them and they are
not modified. Although the program has been extensively tested,
Unitech Associates, Inc. provides no warranty concerning its
usefulness on all systems and UA, Inc. accepts no responsibility
or liability for any mishap resulting from its use.

Questions or comments can be answered by :

Dale S. Hoover ( CompuServe ID #73300,3712 )

or at :

Dale S. Hoover
Vice President
Unitech Associates, Inc.
P.O. Box 566
Newark, DE 19715

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