THIRD-PARTY WORK IN ATRaction

ATRaction is licensed GPL-2.0-or-later (see LICENSE.txt). That choice is not
arbitrary: parts of the disk-format code are derived from GPL-licensed sources,
and this document records exactly which, so that anyone reading or reusing the
code knows what came from where.


1. ALTIRRA / THE ATIO LIBRARY - AVERY LEE
-----------------------------------------

    Project:    https://www.virtualdub.org/altirra.html
    Author:     Avery Lee
    Licence:    GPL-2.0-or-later - every Altirra source file carries the notice
                "either version 2 of the License, or (at your option) any
                later version".

Altirra carries a separate copyright range per source file, so each module
below names the file it draws on together with that file's own range, rather
than one blanket range for everything.

This is the reason ATRaction is GPL. The Atari disk formats themselves are
facts, not protected expression, but the following was reconstructed with
Altirra's source open as the reference, which makes it derived work:

  js/atr.js
      from Altirra/source/uidisk.cpp        (C) 2009-2010 Avery Lee
      Custom disk geometry rules mirroring the "Custom" option of the Create
      New Disk dialog: boot sector count, sector size, and the resulting free
      sector count.

  js/dos2.js
      from ATIO/source/diskfsdos2.cpp       (C) 2009-2015 Avery Lee
      The DOS 2.5 second allocation map (VTOC2 in sector 1024), the
      reserved-sector rules, and the allocation validator, following
      ATDiskFSDOS2::Validate and ATDiskFSDOS2::InitNew.

  js/mydos.js
      from ATIO/source/diskfsdos2.cpp       (C) 2009-2015 Avery Lee
      The paged, multi-sector MyDOS VTOC bitmap model, verified against
      ATDiskFSDOS2::InitNew.

  js/spartados.js
      from ATIO/source/diskfssdx2.cpp       (C) 2009-2015 Avery Lee
      The SDFS allocation bitmap layout, and the sector-size code convention
      of boot sector byte 31 (128 -> 128 B, 0 -> 256 B, 1 -> 512 B).

  js/cpm.js
      from ATIO/source/diskfscpm.cpp        (C) 2009-2021 Avery Lee
      The CP/M 2.2 (Indus GT) filesystem layout and its inverted (XOR $FF)
      byte encoding. The Atari 1090 CP/M profile in the same file is not from
      Altirra, which does not support that format - its geometry was read out
      of the DPB table in the card's own CP/M BIOS.

  js/engine.js
      from ATIO/source/diskfs.cpp           (C) 2009-2014 Avery Lee
      from ATIO/source/diskimage.cpp        (C) 2008-2025 Avery Lee
      from Altirra/source/uidisk.cpp        (C) 2009-2010 Avery Lee
      The filesystem detection order and its boot signatures
      (ATDiskMountImage), the read-only validation mechanism, and
      checkFormatSupport(), which follows IsCurrentFormatSupported().

  _tests/validate_altirra.js
      from ATIO/source/diskfsdos2.cpp       (C) 2009-2015 Avery Lee
      A direct port of ATDiskFSDOS2::Validate, used to cross-check that the
      images ATRaction accepts are images Altirra also accepts. Not part of
      the published site.

The read-only mounting model as a whole - refusing writes when the allocation
map contradicts the directory, rather than silently repairing - follows
Altirra's approach and is applied across every filesystem module, including
those not listed above.

Altirra's own source is NOT redistributed with ATRaction.


2. atari8fs - MONO
------------------

    Project:    http://mono.i-demo.pl/

The Atari DOS 2, DOS 2.5, DOS II+/D and MyDOS 4.5x implementations draw on the
analysis of the ATR and VTOC formats documented by this project. This is format
documentation rather than code reuse.


3. LiteDOS-SE - MR ATARI
------------------------

    Project:    http://www.mr-atari.com/

js/litedos.js - the cluster allocation map, the VTOC/directory area geometry
and the directory entry format follow the technical section of the LiteDOS-SE
user manual. Written from documentation, not from source.


4. EMBEDDED DOS SYSTEM FILES - js/dos_templates.js
--------------------------------------------------

THIS FILE IS THE ONE EXCEPTION TO THE LICENCE. It carries verbatim copies of
third-party boot sectors and system files (DOS.SYS, DUP.SYS) as base64 blobs,
used to install a working DOS when creating a new disk image. They are not the
work of this project, are not covered by the GPL, and no licence over them is
claimed or granted here. Only the surrounding JavaScript - the table structure
and the decoder - is GPL.

  DOS2       Atari DOS 2.0S
             (C) Atari Inc.; rights now held by Atari Interactive.
             Included for retro-computing use.

  DOS25      Atari DOS 2.5
             As above.

  DOS2PLUS   DOS II+/D
             Third-party derivative of Atari DOS 2.

  MYDOS      MyDOS 4.5x
             Charles Marslett / Robert Puff - released to the Atari community
             as freely distributable.

  LITEDOS    LiteDOS-SE
             Mr Atari.

These binaries are included on the same footing as they circulate throughout
the Atari 8-bit preservation community: as a hobbyist archive of software for
hardware discontinued in 1992. If you are a rights holder and want a template
removed, please get in touch and it will be removed.

Anyone redistributing ATRaction should be aware that the GPL covers the source
code, NOT these templates, and that their status differs per entry - MyDOS and
LiteDOS are freely distributable, while the Atari DOS images are tolerated
rather than licensed.


5. BUNDLED FONT - css/AtariClassic.ttf
--------------------------------------

A recreation of the Atari 8-bit system character set, shipped with the app so
that the ATASCII preview and the directory view can render text the way the
original hardware did. It is not the work of this project and is not covered by
the GPL; it is redistributed here in the form in which it circulates in the
Atari community.