Why Diagnostic Software Runs in DOS
-----------------------------------
We get a lot of questions about "When will you have a version for
Windows?" (or Windows 95, Windows NT or OS/2). There is a good
reason why our software (as well as most true diagnostic software
runs in DOS or from a self-booting diskette.

For the purposes of this note, we will define two types of system
testing programs: "diagnostic tools" and "system scanners". 

A "diagnostic tool" is a software program to assist in the
troubleshooting of a hardware failure or hardware and/or software
configuration problem. These tools actually take control of and
test the hardware to determine if it is working, and, if so, what
port address and IRQ it is using. This is the way the shareware
(trial) version of PortInfo operates. An additional feature of
some diagnostics is to verify that the software is set up
properly to use the hardware. The complete version of PortInfo
will also do this by verifying that the Windows SYSTEM.INI file
is correctly set up to use the serial ports.

A "system scanner" is a generic "it's working" or "it's broke" type
of program. They often run in Windows (or Windows 95) and have
real cool user interfaces, but they don't actually test the
hardware. Instead, a system scanner is reporting what the
operating system driver reports. The drivers typically provide
little diagnostic information other than they found (or didn't
find) the device. But at the end, you don't really know a whole
lot more than you did before.

Why do Hardware Testing Programs Run in DOS?
--------------------------------------------
PortInfo (and most other diagnostic tools) run in DOS because
most operating systems (Windows, Windows 95, Windows NT and OS/2)
prevent software from using the hardware directly. This is done
intentionally for a number of reasons, but primarily to make the
system easier to use and to reduce the risk of system lockups
caused by software using the hardware incorrectly.

The operating system uses "device drivers" to control the
different hardware devices. The driver provides a defined
interface for use by applications written for the operating
system and also provides an interface for DOS compatibility. This
causes problems for diagnostic software because the diagnostic
has to work with the driver and cannot access the hardware
directly. This limits the diagnostic to reporting information
that is available from the driver.

Hardware diagnostic programs (like PortInfo) require direct
access to devices for reliable testing. Since DOS is the only
operating system that allows software to access the hardware
directly, you should plan on using DOS for many of the most
useful diagnostics.

How to Test From a Windows Environment 
--------------------------------------
You can obtain some useful information about what ports are
detected and which ports have modems when you run a DOS
diagnostic such as PortInfo from within Windows. However, since
PortInfo is not working directly with the hardware, PortInfo (and
your applications) may not detect a serial port (or modem) if
Windows has not been set up properly. For best results, start by
running in DOS to determine what hardware exists and then run
again from within Windows to verify that all of the hardware
detected by the DOS test is available to your Windows
applications.

Windows 95 Considerations
-------------------------
Windows 95 and Plug-and-Play has made troubleshooting
communications problems more difficult than in the past as there
are a number of new issues to consider. While we are working to
on a good solution for Windows 95 communication setup problems,
we suggest that you continue using PortInfo as before. First, run
PortInfo after you have rebooted into DOS mode (select "reboot to
DOS" from the Windows 95 shutdown menu). Run PortInfo and note
which ports are installed and which port addresses and IRQs are
being used. 

Next, restart Windows 95. Temporarily turn off any communication
applications (especially fax reception programs as these will
allocate and hide the serial port from other applications). Then
run PortInfo from within Windows 95. All of the ports detected in
the first PortInfo run should be listed at the same address and
IRQ. It is also possible that an additional port will appear if
there is a plug-and-play modem installed that was not configured
to operate during the DOS test. If one of the ports is missing,
make certain that another application is not using the port. 

Finally, compare the results from PortInfo with the Windows 95
Device Manager. From the "My Computer" icon, select "Control
Panel" and then "System". The second tab is the "Device Manager".
Under the entry "Ports" there should be a listing for each Com
port in the computer. Select "Properties" and then "Resources" to
see what I/O address and IRQ Windows 95 is using for each port.
If a port is showing different resources than PortInfo indicated,
then try to change the port setting in the device manager by
disabling "Use Automatic Settings" and selecting a configuration
that matches the actual port use. If this does not work, select
Cancel, then Remove the port from the device manager. Restart
Windows 95 and re-install the port by selecting "My Computer",
"Control Panel" and "Add New Hardware". 

Last Update: 8/6/96