             USING INVISIBLE LAN IN AN OS/2 2.1 DOS SESSION

                Copyright 1995 Invisible Software, Inc.



       [See GUIDE.TXT for a list of all manuals and text files.]



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TABLE OF CONTENTS:

 1.  Introduction
 2.  Installing and Configuring the Network Software
 3.  Preparing a Startup Diskette
 4.  Creating a Diskette Image File
 5.  Creating an Icon for the Specific DOS Session
 6.  Starting the Specific DOS Session
 7.  Accessing the Network
 8.  Managing the Specific DOS Session
 9.  Memory Management
    9.1.  Option 1 - Shadow RAM Only
    9.2.  Option 2 - Shadow RAM and Expanded Memory
    9.3.  Network Hardware with Shared RAM
10.  Troubleshooting



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1.  INTRODUCTION


     You can run Invisible LAN in a DOS session under OS/2 version 2.1.
This provides a limited degree of network connectivity for computers
running OS/2 2.1.

     OS/2 has two different kinds of DOS sessions:  regular DOS sessions
and specific DOS sessions.  A regular DOS session provides a simulation
of DOS that can support many DOS programs.  A specific DOS session loads
an actual copy of DOS -- not a simulation -- to support programs that
need to have an actual copy of DOS in memory.

     Invisible LAN needs to run in a specific DOS session, since the
network software needs to have an actual copy of DOS in memory.  For
more information on specific DOS sessions, refer to Appendix E in the
IBM OS/2 2.1 Installation Guide.




2.  INSTALLING AND CONFIGURING THE NETWORK SOFTWARE


     Use the SETUP30 program to install and configure the network
software in the usual way.  You can run SETUP30 in any DOS session
(regular or specific).

     When configuring the network software, observe the following
special requirements:

     *  Do not install the Invisible LAN disk cache.  OS/2 has built-in
        disk caching.

     *  Do not install any Invisible RAM memory managers.

     *  The SOFTWARE VERSION must be STANDARD.

     *  WINDOWS SUPPORT must be set to N.

     You should always install the redirector.  The redirector lets
programs running in the specific DOS session access network disks and
printers.  (If you use the Easy Configuration section of SETUP30, the
redirector is always installed.)

     Optionally, you can also install the server.  If you install the
server, then other computers on the network can access the OS/2 disks
and printers.

     Optionally, you can also install electronic mail.  If you install
electronic mail, then you can send and receive messages to and from
other users on the network.

     Optionally, you can load the network software into shadow RAM
and/or expanded memory.  To do this, you need to install the OS/2 memory
managers described in section 9 below.

     Do not use the SETUP30 program to change the OS/2 CONFIG.SYS file.
The procedure for setting up CONFIG.SYS is described below.




3.  PREPARING A STARTUP DISKETTE


     To set up a specific DOS session, you need to create a DOS startup
diskette.  The startup diskette contains the files necessary for
starting DOS, including COMMAND.COM, CONFIG.SYS, and AUTOEXEC.BAT.


     The first step in creating a startup diskette is to boot a computer
under DOS, and then format a blank diskette using the /S option:

                FORMAT  A:  /S


     The second step is to create a CONFIG.SYS file on the startup
diskette.  You can do this with a text editor.  The recommended
CONFIG.SYS file is this:

                BUFFERS = 20
                FILES = 100
                LASTDRIVE = Z
                FCBS = 16,8
                STACKS = 32,128
                DEVICE = FSFILTER.SYS
                DEVICE = C:\NET30\CACHE30.SYS
                DEVICE = C:\NET30\N30DEV.SYS
                SHELL = C:\DOS\COMMAND.COM  C:\DOS\  /P

     Note that FSFILTER.SYS must be the first device driver, CACHE30.SYS
must be the second device driver, and N30DEV.SYS must be the last device
driver.  Any additional device drivers must be listed after CACHE30.SYS
and before N30DEV.SYS.  For example, if you wanted to install ANSI.SYS
you would use:

                BUFFERS = 20
                FILES = 100
                LASTDRIVE = Z
                FCBS = 16,8
                STACKS = 32,128
                DEVICE = FSFILTER.SYS
                DEVICE = C:\NET30\CACHE30.SYS
                DEVICE = C:\DOS\ANSI.SYS
                DEVICE = C:\NET30\N30DEV.SYS
                SHELL = C:\DOS\COMMAND.COM  C:\DOS\  /P

     Notice that all device drivers except FSFILTER.SYS must have an
explicit drive and path included.  Also, notice that you must specify a
SHELL command that identifies the location of COMMAND.COM on the hard
disk.


     The third step in creating a boot diskette is to create an
AUTOEXEC.BAT file.  At a minimum, this should specify a path that
identifies the locations of DOS and Invisible LAN on the hard disk.

     Optionally, you can also include the NET30 command in the
AUTOEXEC.BAT file.  If you include the NET30 command, Invisible LAN
starts automatically when you launch the specific DOS session.  If you
don't include NET30, then you need to manually enter the NET30 command
after starting the specific DOS session.

     Here is a typical AUTOEXEC.BAT file:

                PATH=C:\DOS;C:\NET30
                SET COMSPEC=C:\DOS\COMMAND.COM
                NET30


     The fourth and final step in creating a boot diskette is to copy
the file FSFILTER.SYS onto the boot diskette.  You can find FSFILTER.SYS
on your OS/2 system, in the C:\OS2\MDOS directory.  Here is how to
perform the copy:

                COPY  C:\OS2\MDOS\FSFILTER.SYS  A:


     Notice that you do not have to copy any of the Invisible LAN files
onto your startup diskette.  The only files that you actually need to
have on the startup diskette are COMMAND.COM, CONFIG.SYS, AUTOEXEC.BAT,
and FSFILTER.SYS (plus the two hidden files that contain the DOS file
system).




4.  CREATING A DISKETTE IMAGE FILE


     After creating the startup diskette, you can transfer its contents
to a file on the hard disk.  This file is called a diskette image file.

     You create the diskette image with the VMDISK program.  You must
run VMDISK from an OS/2 command prompt.  Here is the command format:

                VMDISK  A:  C:\DOS50.IMG

     The first parameter, in this case A:, specifies which floppy
diskette drive contains the startup diskette.  The second parameter, in
this case C:\DOS50.IMG, specifies the name of the image file that VMDISK
creates.  You may specify any name you want for the image file.




5.  CREATING AN ICON FOR THE SPECIFIC DOS SESSION


     After creating the image file, you need to create an icon that
refers to the image file.  Once the icon is created, you can
double-click on the icon to start the specific DOS session.

     To create the icon:

     *  Open "OS/2 System".

     *  Open "Command Prompts".

     *  Display the pop-up menu for "DOS Window" by clicking on the icon
        and then pressing mouse button 2.  (You can use "DOS Full
        Screen" instead if you prefer to run your DOS sessions in full
        screen mode.)

     *  Select "Create Another".

     *  Point to the newly created icon and press mouse button 2.

     *  Select the arrow next to "Open", and then select "Settings".

     *  Click on the "Program" tab.

     *  Type "*" in the "Path and file name" field.  (Don't type the
        quotation marks, just type the asterisk.)

     *  Click on the "Session" tab.

     *  If you want your specific DOS session to run in a window, click
        on "DOS Window".  If you want your specific DOS session to run
        in full-screen mode, click on "DOS Full Screen".

     *  Click on "DOS Settings".

     *  Select "DOS_STARTUP_DRIVE", and then type the name of the
        startup diskette image file (for example, "C:\DOS50.IMG").

     *  Select "INT_DURING_IO", and then click on "On".

     *  Click on "Save".

     *  Click on the "General" tab, and type "Invisible LAN" in the
        "Title" field.

     *  Close the DOS Settings window by double-clicking on the title
        bar icon.




6.  STARTING THE SPECIFIC DOS SESSION


     To start the specific DOS session, double-click on the new icon you
created, which is named "Invisible LAN".

     When you start the specific DOS session, it starts as if you were
booting from a diskette in drive A:.  The commands in the CONFIG.SYS and
AUTOEXEC.BAT file are executed.  If you put the NET30 command in the
AUTOEXEC.BAT file, the network software starts automatically.

     If you didn't put the NET30 command in the AUTOEXEC.BAT file, then
you need to manually type "NET30" at the DOS prompt to start the network
software.

     Note:  If you get an "Interrupt test failed" message when TransBIOS
is loading, it means that TransBIOS cannot find the interrupt level
(IRQ) used by the network adapter.  To correct this problem, run
SETUP30, go to Advanced Configuration, TransBIOS Parameters, and set the
Hardware IRQ Level parameter to specify the interrupt level used by your
network adapter.




7.  ACCESSING THE NETWORK


     Only one specific DOS session can run the network software.
Network disks and printers are only accessible to programs running
within that one specific DOS session.  Network disks and printers are
not accessible to OS/2 programs, or to Windows programs running in
WIN-OS/2, or to DOS programs running in other DOS sessions.

     If you load the file server, other computers on the network can
access the OS/2 disks and printers.

     If the server is configured as a print server, there are two ways
that the server can access the printer:  PORT or BIOS.  You select the
access method in the Advanced Configuration, Print Spooler Parameters
section of the SETUP30 program.  The default method is PORT.

     *  When you select PORT, the server sends print jobs directly to
        the printer port hardware.  In this case, the printer is
        reserved exclusively for use by the server.  OS/2 programs
        cannot access the printer.

     *  When you select BIOS, the server sends print jobs to the printer
        BIOS, which in turn sends the jobs through the OS/2 print
        spooler.  This allows the printer to be used by OS/2 programs.
        However, the OS/2 print spooler has no way of knowing where
        network print jobs begin and end.  This may create some
        difficulties.  If you want to use the BIOS access method, you
        should probably disable DIRECT PRINT.  Also, you may need to
        adjust the PRINT_TIMEOUT value in the "DOS Settings" window.

     If you load electronic mail, you can send and receive messages to
and from other users on the network.  To send a message, activate the
specific DOS session and then press Ctrl+Alt+Backspace.  When you
receive a message, the speaker beeps three times and the mail program
pops up onto the DOS session's screen.  If the DOS session is not
visible when you receive a message, you hear the three beeps but you
cannot see the message until you activate the DOS session.




8.  MANAGING THE SPECIFIC DOS SESSION


     When you start the specific DOS session, drive letter A: refers to
the startup diskette image file.  You can read and write this diskette
image just as if it were a real diskette.  Since the diskette image is
writable, you can make changes in your CONFIG.SYS and AUTOEXEC.BAT
without creating a new startup diskette.  You can simply use any DOS
text editor to edit the CONFIG.SYS and AUTOEXEC.BAT on the simulated A:
drive.

     If you want to access your floppy diskette drive, you need to use
the command "FSACCESS A:" to discontinue the use of the image file.  You
can find FSACCESS.EXE in your C:\OS2\MDOS directory.

     To switch away from the DOS session so you can work with another
OS/2 program, press Ctrl+Esc.  (If the DOS session is running in a
window, you can also use the mouse to switch to another program.)  While
you are working with the other program, the network software continues
to run in background.

     To terminate the specific DOS session, you can type the command
"EXIT_VDM" at the DOS prompt.  You can find EXIT_VDM.COM in your
C:\OS2\MDOS directory.  You can also terminate the specific DOS session
by selecting Close from the pop-up menu in the OS/2 Workplace Shell.




9.  MEMORY MANAGEMENT


     OS/2 includes two special device drivers that provide memory
management within a specific DOS session.  They are called HIMEM.SYS and
EMM386.SYS.  HIMEM.SYS provides shadow RAM (also called upper memory),
XMS memory, and the high memory area.  EMM386.SYS provides expanded
memory (also called EMS memory).  Both of the device drivers can be
found in your C:\OS2\MDOS directory.

     Note that these device drivers are quite different from the DOS
device drivers called HIMEM.SYS and EMM386.EXE.  The two main
differences are:  (1) Under OS/2, shadow RAM is provided by HIMEM.SYS;
under DOS, shadow RAM is provided by EMM386.EXE.  (2) Under OS/2, you
specify parameters in the "DOS Settings" window;  under DOS, you specify
parameters on the DEVICE= line in the CONFIG.SYS file.

     There are two main options for memory management:  you can have
just shadow RAM, or you can have both shadow RAM and expanded memory.
These options are discussed separately below.


9.1.  OPTION 1 - SHADOW RAM ONLY


     If you want to have just shadow RAM, you need to install HIMEM.SYS
in your DOS CONFIG.SYS file.  Here is what the CONFIG.SYS file should
look like:

                BUFFERS = 20
                FILES = 100
                LASTDRIVE = Z
                FCBS = 16,8
                STACKS = 32,128
                DEVICE = FSFILTER.SYS
                DEVICE = C:\NET30\CACHE30.SYS
                DEVICE = C:\OS2\MDOS\HIMEM.SYS
                DEVICE = C:\NET30\N30DEV.SYS
                SHELL = C:\DOS\COMMAND.COM  C:\DOS\  /P

     You can use the DOS=HIGH and DOS=UMB commands in your CONFIG.SYS
file in the usual way.  DOS=HIGH loads most of DOS into the high memory
area.  DOS=UMB makes shadow RAM (also called upper memory blocks)
available to DOS applications.  Invisible LAN can use shadow RAM
regardless of whether or not you include DOS=UMB.  However, most other
programs can't use shadow RAM unless you include DOS=UMB.

     In addition to changing the CONFIG.SYS file, you also need to make
some adjustments to your "DOS Settings".  Use the following procedure:

     *  Display the pop-up menu for the "Invisible LAN" icon by clicking
        on the icon and then pressing mouse button 2.

     *  Select the arrow next to "Open", and then select "Settings".

     *  Click on the "Session" tab.

     *  Click on "DOS Settings".

     *  Select "EMS_FRAME_LOCATION", and then select "NONE" from the
        drop-down list.

     *  If your network hardware uses shared RAM, select
        "MEM_EXCLUDE_REGIONS", and then type in the range of memory
        addresses used for shared RAM.  For example, if your network
        hardware uses shared RAM at segments D000-D3FF, you would type
        in "D0000-D3FFF".  Notice that you need to type the memory
        addresses using five hexadecimal digits, instead of the usual
        four hexadecimal digits.  (Shared RAM is used by Western Digital
        compatible Ethernet adapters.  See section 9.3 for details.)

     *  Other settings that you may want to adjust are:
        MEM_INCLUDE_REGIONS, XMS_HANDLES, XMS_MEMORY_LIMIT, and
        XMS_MINIMUM_HMA.  Refer to the OS/2 online documentation for
        details.  In most cases, the default values give acceptable
        results.

     *  Click on "Save".

     *  Close the DOS Settings window by double-clicking on the title
        bar icon.


9.2.  OPTION 2 - SHADOW RAM AND EXPANDED MEMORY


     If you want to have both shadow RAM and expanded memory, you need
to install HIMEM.SYS and EMM386.SYS in your DOS CONFIG.SYS file.  Here
is what the CONFIG.SYS file should look like:

                BUFFERS = 20
                FILES = 100
                LASTDRIVE = Z
                FCBS = 16,8
                STACKS = 32,128
                DEVICE = FSFILTER.SYS
                DEVICE = C:\NET30\CACHE30.SYS
                DEVICE = C:\OS2\MDOS\HIMEM.SYS
                DEVICE = C:\OS2\MDOS\EMM386.SYS
                DEVICE = C:\NET30\N30DEV.SYS
                SHELL = C:\DOS\COMMAND.COM  C:\DOS\  /P

     You can use the DOS=HIGH and DOS=UMB commands in your CONFIG.SYS
file in the usual way.  DOS=HIGH loads most of DOS into the high memory
area.  DOS=UMB makes shadow RAM (also called upper memory blocks)
available to DOS applications.  Invisible LAN can use shadow RAM
regardless of whether or not you include DOS=UMB.  However, most other
programs can't use shadow RAM unless you include DOS=UMB.

     In addition to changing the CONFIG.SYS file, you also need to make
some adjustments to your "DOS Settings".  Use the following procedure:

     *  Display the pop-up menu for the "Invisible LAN" icon by clicking
        on the icon and then pressing mouse button 2.

     *  Select the arrow next to "Open", and then select "Settings".

     *  Click on the "Session" tab.

     *  Click on "DOS Settings".

     *  Select "EMS_FRAME_LOCATION", and then select "AUTO" from the
        drop-down list.  (Alternatively, you can select the actual
        memory address where you want the EMS page frame to be located.)

     *  If your network hardware uses shared RAM, select
        "MEM_EXCLUDE_REGIONS", and then type in the range of memory
        addresses used for shared RAM.  For example, if your network
        hardware uses shared RAM at segments D000-D3FF, you would type
        in "D0000-D3FFF".  Notice that you need to type the memory
        addresses using five hexadecimal digits, instead of the usual
        four hexadecimal digits.  (Shared RAM is used by Western Digital
        compatible Ethernet adapters.  See section 9.3 for details.)

     *  Other settings that you may want to adjust are:
        EMS_HIGH_OS_MAP_REGION, EMS_LOW_OS_MAP_REGION, EMS_MEMORY_LIMIT,
        MEM_INCLUDE_REGIONS, XMS_HANDLES, XMS_MEMORY_LIMIT, and
        XMS_MINIMUM_HMA.  Refer to the OS/2 online documentation for
        details.  In most cases, the default values give acceptable
        results.

     *  Click on "Save".

     *  Close the DOS Settings window by double-clicking on the title
        bar icon.


9.3.  NETWORK HARDWARE WITH SHARED RAM


     Some network hardware uses shared RAM.  "Shared RAM" is memory on
the network board that is directly accessible to the PC.  Shared RAM
always occupies a range of memory addresses within the upper memory
area, that is, between addresses C000 and EFFF.

     Most network boards do not use shared RAM.  The most common network
boards that use shared RAM are Western Digital compatible Ethernet
boards.

     Here is a list of network boards, indicating which do and do not
use shared RAM:

     Does Not Use Shared RAM         |  Uses Shared RAM
     --------------------------------+--------------------------------
     Invisible Models 100, 200, 300  |  Western Digital 8003 Ethernet
                                     |
     Invisible Models 200/A, 300/A   |  Western Digital 8013 Ethernet
                                     |
     Invisible Ethernet-8            |  Invisible Ethernet 2000S (when
                                     |     configured in WD mode)
     Invisible Ethernet-16           |
                                     |  Invisible Ethernet VL
     Invisible Ethernet/A            |
                                     |  IBM Token Ring
     NE1000 compatible Ethernet      |
                                     |
     NE2000 compatible Ethernet      |
                                     |
     NE/2 compatible Ethernet        |
                                     |
     Invisible Ethernet 2000S (when  |
        configured in NE2000 mode)   |
                                     |
     Printer Port Ethernet           |


     When using network hardware with shared RAM, you must specify the
shared RAM address in the MEM_EXCLUDE_REGIONS parameter of the "DOS
Settings" window.  The procedure for doing this was described in
sections 9.1 and 9.2 above.




10.  TROUBLESHOOTING


     The following paragraphs describe some problems that may occur when
running Invisible LAN under OS/2, and how to resolve them.

     If you get an "Interrupt test failed" message when TransBIOS is
loading, it means that TransBIOS cannot find the interrupt level (IRQ)
used by the network adapter.  To correct this problem, run SETUP30, go
to Advanced Configuration, TransBIOS Parameters, and set the Hardware
IRQ Level parameter to specify the interrupt level used by your network
adapter.

     If you get a "Static RAM test failed" message when TransBIOS is
loading, it means that TransBIOS cannot access the shared RAM on the
network adapter.  To correct this, go to the "DOS Settings" window, and
set the MEM_EXCLUDE_REGIONS parameter to specify the address of the
shared RAM.

     If network sessions are aborted when OS/2 programs are running, it
means that the specific DOS session is not getting enough CPU time.  To
correct this, go to the "DOS Settings" window, and set the
IDLE_SENSITIVITY parameter to 100.  If that doesn't solve the problem
then run SETUP30, go to Advanced Configuration, TransBIOS Parameters,
and set the Retry Limit to 32.  (The Retry Limit adjustment has to be
done both on the computer running OS/2, and on other computers in the
network that are communicating with the OS/2 computer.)

     If the network software won't load into shadow RAM, it may be that
some program is scanning the upper memory area.  For example, the SHADOW
program included with Invisible LAN scans memory to find all the RAM and
ROM in the system.  If you run such a program before loading the network
software, the shadow RAM may be disabled.  To correct this problem,
either (a) don't run any memory scanning programs until after the
network is loaded, or (b) add DOS=UMB to your DOS CONFIG.SYS file.

     If DOS programs running in the specific DOS session seem to execute
very slowly, there are two things you can try to speed them up:  (a) If
the DOS session is configured to run in a window, change it to run
full-screen.  (b) Go to the "DOS Settings" window, and set the
IDLE_SENSITIVITY parameter to 100.
