although care has been taken to maintain system compatibility by using
     the same input/output signals as before. In fact, a more radical
     simplification of the input/output relations of the aircraft model can
     be obtained here, but that will be postponed for a future release of
     the toolbox.

*  A completely new on-line help facility, based upon HTML language, has
   been created. As in FDC 1.2, double-clicking on title blocks in Simulink
   diagrams opens the on-line help facility, but the new version uses a
   web-browser to show the help texts (note: the on-line help facility won't
   function without a web-browser!). Some advantages:

   - fundamentally improved lay-out and enhanced readability
   - hyperlinks provide connections to related subjects in the on-line help
     database

   Moreover, additional help-texts for APINIT, APMODE, NAVLIB, WINDLIB, and
   RECOVER have been created, and a large number of small errors and
   omissions in the old help texts (*.HLP) have been fixed. In addition,
   pressing the HELP button of a masked Simulink block from the FDC toolbox
   now provide an automatic link to your web-browser. The HELP subfolder
   of the FDC toolbox still contains the old *.HLP files (even slightly
   improved ones) for compatibility reasons.

   Note: typing fdchelp('index') at the command-line will reveal the index-
   page of the HTML-helpfiles for FDC 1.3.

*  Clicking the HELP button of masked subsystems now provides a direct link
   to the new HTML helpfiles. Much more comfortable than before!

*  Many small editorial changes to the models and tools help improve their
   readability.

*  Autopilot systems: button-blocks now contain the names of the Matlab
   routines which will run after the blocks are double clicked. Subsystem
   `Computational Delay & Limiters' has got its own on-line help text.

*  Graphical systems now stored in the new MDL format of Simulink 2.
   The `button'-library BUTTONS has been renamed to FBUTTONS to prevent
   clashes with the new Matlab 5 routine BUTTONS.M.

*  FDCLIB, NAVLIB, and WINDLIB are now saved as Simulink libraries instead
   of 'ordinary' Simulink models (also a new feature of Simulink 2).

*  To prevent Simulink from issuing warning messages about blocks which
   were purposedly left unconnected, the ground and termination blocks
   from Simulink 2 have been applied. This is for instance clearly
   visible in the systems OLOOP1, OLOOP2, and OLOOP3 and the autopilot
   systems. If you don't mind the warning messages you may delete these
   blocks, since their appearance in the graphical systems is actually
   quite ugly...

*  Several blocks from the Simulink block-diagrams were replaced by new
   Simulink 2 versions.

*  Removed revision dates from title blocks of subsystems. Revision date
   is now only shown in masked subsystems and top-level (saves me a lot of
   time and prevents confusing mistakes). Replaced title blocks for auto-
   pilot control modes by simple blue text-line and added similar lines to
   autopilot-blocks which previously didn't have a title-block at all.

*  All graphical block-diagrams are now optimized for a screen-resolution
   of 800x600 pixels or more (was 640x480 or more).

*  Formatted most Mux blocks as thin black bars (making the systems easier
   to understand).

*  Added revision history lists to the Matlab programs.

*  The autopilot initialization routines have been improved by eliminating
   command-window messages where possible (not yet realized for places where
   user inputs are required).

*  Installation routine has been streamlined, using new self-extracting
   ZIP technology for MS-Windows. Default destination directory for the
   installation will now be C:\MATLAB\TOOLBOX\FDC13 (can be changed
   easily during the installation, e.g. if your Matlabroot is not equal
   to C:\MATLAB) and default directory used by FDC initialization routines
   is set to MATLABROOT\TOOLBOX\FDC13.

*  CONTENTS.TXT file from the subfolder DOC now only contains a file-list.
   More information is available in the CONTENTS.M files, which will be
   shown if you use HELPWIN at the command-line and double-click the
   references to the FDC subfolders.

*  FDCINIT.M now shows graphically more appealing welcome screen, which
   isn't as irritating for new users as the old welcome-screens. Furthermore,
   a menu is displayed after initialization, guiding the user to the main
   FDC library (FDCLIB) or the on-line help-texts as desired. Many smaller
   changes in this utility have improved the path-definitions for the FDC
   toolbox (hopefully eliminating some of the compatibility problems expe-
   rienced by users who ran FDC on a UNIX machine or MAC).


FDC 1.2.1
=========
*  This is the first release that has been made available on SourceForge.
   It is largely identical to FDC 1.2, but it contains some minor changes
   in the user-interface and it includes HTML helpfiles (although the latter
   are not actually integrated in the FDC software; they are an 'add-on'
   only). 

*  FDC 1.2.1 has been re-licensed under the Dutchroll Open Source Software 
   License (DOSSL) version 1.0 (described in the LICENSE.TXT document of 
   this release).


FDC 1.2
=======
This is the first version of the toolbox that was actually called 'Flight
Dynamics and Control toolbox'. It contained the following new features:

*  FDC 1.2 was designed for Matlab 4.0 / Simulink 1.2c (or newer) instead
   of Matlab 3.5k / Simulink 1.2.

*  The masked blocks did not use 'hidden' parameters, read from global
   variables in the workspace, contrary to the previous versions.

*  The help texts were improved once again. Toolbox-help in 'Matlab 4.0'-
   style (contents.m files) and new help-files for the autopilot simulation
   models were included.

*  The autopilot simulation models were improved in order to make them
   better accessible by the users. The autopilot-parameter definition
   routines were made more user-friendly than before and the on-line help
   texts for these models were improved.

*  Three new examples of control-law simulations were added. These systems
   (PAH.M, RAH.M, and PAHRAH.M) represented an interim step between linear
   autopilot design and the full-featured non-linear autopilot models from
   the systems APILOT1 to APILOT3. The routine PRAHINIT.M was included to
   help definining the parameters for these example systems.

*  The Mode-controller blocks from the autopilot simulation models was
   renewed completely, together with the Matlab functions GSSWITCH.M,
   NAVSWTCH.M, and LOCSWTCH.M, which are called by S-function blocks in
   the Mode Controller subsystem. Some of the mode-definition vectors
   were re-defined in the new mode-controller and the old initialization
   routine APSTART.M was replaced by APMODE.M.

*  A user-menu APMENU.M was included in order to help the user in selecting
   the appropriate autopilot model.

*  New Matlab macros RESULTS.M and RESPLOT.M were included to facilitate
   the post-processing of simulation results.

*  The screen-formatting of the routines ACLIN and ACTRIM was improved by
   applying a slightly changed version of the Matlab function NUM2STR,
   called NUM2STR2.

*  Complete lists of variables were added to the source codes of ACLIN and
   ACTRIM. The source-codes themselves were better documented.

*  Several blocks from the library FDCTOOLS (previously called TOOLS)
   were improved. This library was equipped with a user-friendly n-switch
   generator which automatically created graphical switch-blocks with n
   inputs, where n could be specified by the user during the block-
   generation process.

*  Several minor and some major bugs in the Matlab programs from the FDC
   toolbox were fixed. The package was made more 'fool-proof'.

*  The program documentation files (*.TXT) was gathered in a new
   subdirectory DOC, leaving only the FDC initialization and installation
   routines in the root directory of the toolbox.

*  The installation routine was improved, allowing installation into a
   different destination directory than C:\FDC12. The self-extracting
   ZIP-file that contained the FDC toolbox distribution files was hidden
   from the user to prevent the files from being installed to a wrong
   directory.

*  A small routine RECOVER.M was created to recover simulation results 
   that were not properly sent to the Workspace by Simulink.

*  The initialization routine now added the root-directory of the FDC
   toolbox to the Matlab path in order to allow several routines from
   FDC 1.2 to find the default directory settings in the file MODINIT.INI,
   thus reducing the number of 'File not found' errors.

*  A start was made to create an object-oriented implementation of the FDC
   toolbox by putting some often-used parts of programs into general-purpose
   subroutines, but further improvements are still necessary.

*  Created slightly modified Simulink models for Matlab 4.2/Simulink 1.3.


Version 1.1 (beta)
==================
This version was called BEAST 1.1 (beta), which meant 'Beaver Simulation
Toolbox' version 1.1. It was never 'officially' released. Compared to
version 1.0 it contained the following new and/or improved features:

*  Better on-line help texts for the graphical Simulink systems. These
   texts now contained complete lists of variables and units of measurements.
   The number of help texts was increased considerably. Moreover, the file-
   extension for these help texts was changed from .M to .HLP.

*  Double-clicking title-blocks in graphical Simulink systems now listed
   the accompagnying help-texts in the Matlab command-window.

*  New file-extensions were introduced: .DAT (parameter files),
   .HLP (helpfiles), .LIN (linearized models), and .TRI (trimmed-flight
   conditions). This clarified the file-structure of the toolbox.

*  The user-interface of ACTRIM and ACLIN was considerably improved.

*  The trim-routine was enhanced with the option to specify the
   manifold pressure in stead of the flight path angle.

*  The old model library ACLIB was replaced by the new model library
   BEASTLIB and enhanced with many explanatory systems. All examples were
   now accessible through the main library.

*  New versions of the open-loop example systems from version 1.0 were
   created, plus 'tutorial' systems which gave a step-by-step explanation
   about the meaning of all blocks from these examples.

*  The 'button'-blocks were changed in order to show which M-file they
   would start when being double-clicked.

*  The structure of the aircraft model BEAVER was improved by adding a
   new subsystem 'Additional Outputs' to group the output blocks which
   could not logically be placed elsewhere, and by putting the help sines
   and cosines in a feedback-loop to make them available for ALL other
   blocks within the system. Also, the subsystem 'Aircraft Equations
   of Motion' was restructured in a more logical way. Feedback-loops in
   the system BEAVER were highlighted by a magenta color.

*  Some signal names which could have led to confusion in version 1.0
   were changed (e.g. FMa in stead of Fa, to denote Forces AND Moments).

*  Some bugs in the blocks ACCEL, FLPATH, and XDOTCORR of the old version
   of the system BEAVER were fixed in BEAST 1.1 (bugs reported by Zainal
   Abidin, Delft University of Technology).


Version 1.0
===========
The first usable version of the FDC toolbox that was presented in public
as part of the MSc-thesis of the author. At the time of publishing it 
was still nameless.



-------------------------------------------------------------------------
The FDC toolbox. Copyright M.O. Rauw, 1994-2005. All rights reserved.
This software is licensed under the Open Software License, version 2.1.
See the file copying.txt in the DOC subdirectory for detailed information
about the terms of use.
-------------------------------------------------------------------------