FlexNet Documentation
FlexNet for Windows95 Add On Package

This document describes features and the basic installation procedure for the PC/FlexNet for WIndows95 Add On Package.

An Overview

A good while ago, in April 1996 at the Packet Radio Conference in Darmstadt a first implementation of FlexNet for Windows 95 was introduced. In the first euphoria it was promised to have the whole package available no later than the HAM RADIO-Conference. Unfortunately, many details had to be worked out until a reliable solution could be found.

The draft, which finally is based on the Alphatest-stage is assembled as in the following: The FlexNet modules (kernel and driver) are still available as DOS-Versions, which means they still run under DOS. Therefore the istallation method remains the same for the time being.

The program has to be installed under DOS, before starting Windows. However, all modules can adjust to the new conditions after starting Windows. Especially the Interrupt-Routines of the drivers are now "dual mode" which means, depending on the machine's condition, they are executed in Real- or Protected Mode, supported by a 32bit-virtual driver (VxD). Therefore the same performance as under DOS was obtained, concerning the interrupt latency. Basically, the drivers are compatible to the 3.3e-versions, which means they can be mixed. The desired performance under Windows can only be achieved with the new drivers.

If using a DOS-installation, an update is also recommended. Aside from the Windows support the kernel itself had only one change - 1 letter. It now has the number 3.3f.

Upgrading to PC/Flexnet V 3.3f

Attention should be paid to the following: The following files have to be replaced by newer versions:


This means, these modules can not be mixed with the 3.3e-versions. A final 3.3f version of FLEXDIGI is not available yet. Due to the fact that the use of Windows on a node is not advisable, there are no special priorities for that. Digipeaters should run the 3.3e-version.

Important changes concerning the Ethernet support are:

    The previous drivers (IPXN, IPXD, IPPD and ETHER) do not work under Windows 95. The Ethernet cards are administred by Windows and therefore must be installed under Windows. Of course IPX and AXIP still work (only UDP until now) but a new driver called ETHER32 is needed.

Not all drivers have been adjusted to the Windows environment yet. USCC will work soon, the tests are not completed yet.

Installation of PC/FlexNet V3.3f under Windows 95

The title says it all:

FlexNet is not intended to be used under older Windows-versions.

All higher functions are carried out in 32bit-modules. If Windows 3.1 is used, FLEXNET.VXD may not be installed in the FlexNet-directory, as this may lead to problems.

Before installing FlexNet, the Windows hardware manager should be checked. The necessary resources for the FlexNet drivers (i. e. COM- and LPT-ports) should not show any conflicts. Any installed printers or modems will be disconnected by FlexNet anyway, this means, they should be deinstalled from the begin with. Basically the system has to run stable and the hardware manager should not show any problems before installing FlexNet, otherwise the results are unpredictable - you should not expect a more stable system after installing the package.

The installation of the basic modules (kernel and hardware drivers) is the same as in DOS:

  • All needed modules are copied into the FlexNet directory. It is important that the new flexnet drivers are there, too!
  • A batch file (e.g. LOADFLEX.BAT) has to be created, which loads the modules with the parameters needed. This file is loaded with "CALL LOADFLEX.BAT". Of course everything can be copied into the AUTOEXEC.BAT as well.
  • The PATH environment variable has to show the FlexNet directory.
  • The new modules "FLEXNET.VXD", "FLEXCTL.EXE" and the ".DLL" also have to be found in the FlexNet directory. They are referred to automatically.
  • MSVCRT.DLL may be copied into the Windows system directory as well.

After the modules are sorted, the system should be booted into DOS (not in a DOS-Box under Windows!!). After loading a terminal program (e.g. BCT) everything should run as usual. If not, then it is advisable to find the error now, otherwise the start of Windows is useless.

If everything works well, Windows can be booted. After the GUI has been activated, the FlexNet-Logo shows up for a few seconds, offering a menu. If an error is reported instead or additionally, fix it and try again.

The taskbar should show the FlexNet logo. When clicking on it, a small menu with various modules is opened. These modules should be self-explanetory. They were not build to win a beauty-contest, they just offer some basic functionality.


If everything is working well so far, applications can be started. Any DOS application (e.g. a terminal program) should be run in its own DOS-Box. It is a good idea to use a Windows "shortcut" for this and put an icon on the desktop. Many DOS programs need the WA8DED hostmode compatibility driver "TFEMU" to access the Flexnet Kernel. It has to be called individually in the respective DOS box. So the easiest way would be a batch file which first loads TFEMU and afterwards starts the program. Again a Windows "shortcut" is the easiest way to conveniently start the batch file.

32bit applications are under development by several authors, so wait for many interesting new applications to be available in the near future.

Important: the applications have to use different MYCALLs (or SSIDs)! Otherwise there may be conflicts in the outgoing QSOs. For incoming QSOs it would be undefined which application will get it.

The trace mode (monitor) is still quite limited. Only one application can use trace mode, all other applications should have trace disabled. Here an improvement is under development which will be introduced together with the 32bit version of the PC/Flexnet package.

Ethernet drivers

Due to the fact that the network-cards are administred by Windows using 32 bit drivers, an access by the old packet drivers is not possible. Therefore a special driver called ETHER32 was created which is installed as a normal FlexNet-driver for the desired number of channels, after installing the required protocols (IPX and/or TCP/IP for AXIP) under Windows. More information can be found in the corresponding Microsoft documents. For IPX, the frame type has to be set to "Ethernet II". At least here the "AUTO" setting was not working. The Ethernet channels are only available after starting Windows.

The command line parameters for ETHER32 are described in ETHER32.DOC. The protocol type for every channel is entered; for AXIP_UDP additionally the IP destination is needed.

After starting Windows, the parameters can be checked or changed using "ETH32CFG". This can be done in a DOS box under Windows. The corresponding Windows sockets (WSOCK32) are needed for communication with the Ethernet. The own IP address and other parameters are entered in the network configuration (control panel).

The corresponding link to the Windows networking kernel is internally carried out by several modules: FLEXNET.VXD, FLXAP32.DLL and FLEXCTL.EXE. They are loaded automatically, the "FlexNet Control Center" performs as a helper application to link the modules.


If you are familiar with PC/FlexNet for DOS, the update does not hold any surprises. Simply copy all the modules into the FlexNet directory and start with your old batch file. The only exception is Ethernet (and HB9JNX's soundmodem modules).

As a beginner, first read the documents attached to the modules. It is necessary to boot DOS first and test the package. Only if everything runs without errors, Windows should be booted, and new features can be explored. This includes the TCP/IP-support. Then the Ethernet driver may be installed if needed. If following this order, possible problems can be pinpointed easier. If the whole package is installed at once it may be hard to find the source of a problem.

73' and have fun with all the new stuff

original from: Gunter Jost, DK7WJ
translation: Alexander Kurpiers, DL8AAU
pages created by Matthias Welwarsky, <dg2fef@uet.th-darmstadt.de>
last edited: 28.03.97