
                  Virtual Long Filename Support Driver (VLFN)
                  -------------------------------------------

                   Version 0.81  (preview, work-in-progress)


What is VLFN?
-------------

  By installing this package, you'll be able to use long filenamed files in
  your OS/2's DOS box, the same way as you see them in WinXX.

What does it mean 'Version 0.81'?
---------------------------------

  This program is still under development, it's not ready yet! It means, that
  it will not work perfectly. There is a big possibility that most of the DOS
  programs will not run (yet) in the DOS session where VLFN is activated.

  It also means that it is not bugfree.
  (See Warning section!)

How to install?
---------------

  - Unzip the program somewhere, let's say to C:\VLFN.
  - Add the following lines to your config.sys:
    DEVICE=C:\VLFN\VLFNMEM.SYS
    DEVICE=C:\VLFN\VLFN.SYS
  - Reboot
  - Start VLFND.EXE

  At this stage, VLFN is ready to serve your DOS sessions.
  If you want a DOS session to have Long Filename (LFN) support, start
  LFN.COM there, that's all.

  Now you can check the DIR command, or for example try
  'copy c:\config.sys copyofconfigsys.txt'

Not bugfree. So, why release?
-----------------------------

  I had no time do develop it for about 4 months now. By releasing it, I want
  to force myself to work more on it.:)

Warning!
--------

  Some parts of this program run in RING 0, as device driver. If something
  bad happens there, it can cause TRAP or system halt. Keep in mind that it is
  still a preview version, so *don't run it on machines on which life depends*!

How does it work?
-----------------

  As I know, there is no way to access long filenamed files from DOS sessions
  through normal file handling functions. Only OS/2 executables can see and use
  them.

  So, the program redirects all file operations from a DOS session to an OS/2 
  executable (VLFND.EXE), which makes everything instead of the DOS session,
  and converts long filenames to short ones and vice versa.

  To remember long filenames on FAT drives, and short filenames on HPFS/JFS/etc
  drives, it uses Extended Attributes to store these special filenames with
  the files. It uses .LONGNAME attribute on FAT drives, and .SHORTNAME on the
  others.

  All this work is done by the VLFN Daemon, VLFND.EXE.

  VLFN.SYS is a virtual device driver, which offers services for DOS sessions.
  In our case, these services are the LFN-enabled file operations. If a DOS 
  session want something from VLFN.SYS, it sends a request to VLFN.SYS, which
  redirects it to the daemon.

  VLFNMEM.SYS is a (character) device driver. It's only job is to reserve 128K
  memory as a communication buffer between VLFN.SYS and VLFND.EXE, and give the
  address of this buffer to everybody who asks for it.

  By running LFN.COM in a DOS session, this TSR (resident program) will take
  INT21, and call into VLFN.SYS if some services are needed. In other words,
  by running LFN.COM, you 'turn on' LFN support in a DOS session.

To-do (plans):
--------------

  - Make it work. Still not very shiny.
  - Implement WinXX DOS-based LFN functions, and report WinXX to DOS applica-
    tions. It will be easy after every other thing works.

How to contact the author?
--------------------------

  If you have any comments/questions, feel free to send a mail to
  Doodle <kocsisp@dragon.klte.hu> !

  Please don't report bugs and 'Cubic Player does not start' things, because
  I know. It is still a very buggy version.

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