Omnivore

Abstract

Omnivore - the Atari 8-bit binary editor sponsored by the Player/Missile Podcast

While producing the Player/Missile podcast, I have had many ideas about hacking code on the 8-bits like I used to as a kid. One of the tools I had was the Omnimon system monitor board by CDY Consulting, an add-on board for the Atari 800 that provided a ROM-resident monitor similiar to what was available by default on the Apple ][ series. In fact, I originally named this program Omnimon but felt that would be too confusing as there are people in the 8-bit community who still use the original Omnimon hardware. Using the prefix "Omni-" is my tribute to all the fun I had with the Omnimon hardware.

Omnivore is a cross-platform app for modern hardware (running linux, OS X and Windows) to work with executables or disk images of Atari 8-bit machines. (I have long- term goals to support editing MAME ROMS and disk images of other 8-bit machines like the C64 and Apple ][.)

Omnivore is more than an Atari binary editor. It can also create and edit maps using character-based graphic tiles. For instance: many games use the 5-color ANTIC modes 4 or 5 to provide a complex scrolling background while using much less memory than the multi-color bit-mapped modes.

In addition to supporting more platforms, I also intend to add support for editing character sets and player-missile graphic shapes.

How To Run Omnivore

Note that this is still beta-level software, so caveat emptor.

Binaries are available for Windows 7 and later (64-bit only) and Mac OS X 10.9 and later and at the home page or directly through the github releases page.

Binaries for linux are not currently available, although I would like to provide packages for Ubuntu, Linux Mint and Gentoo at some point. To run on linux, you'll have to install it from source. It's not that complicated; apart from wxPython, everything can be installed from the Python Package Index using pip.

Installing From Source

If you're interested in hacking on the code or making bug fixes or improvements, you can install and run the source distribution.

If you're running linux (like me!), I'd recommend you set up a python virtual environment with all the dependencies you need in there, rather than cluttering up your system's python.

On OS X, I have had difficulty with installing wxPython in a virtualenv, so I had to resort to installing it using the default DMG on the wxPython site and using the framework install of python 2.7, not the system's python.

I do not develop on Windows at all, but for testing purposes I have a virtual machine dedicated to Omnivore development and install everything in the system python in that VM.

Prerequisites

• python 2.7 (but not 3.x yet) capable of building C extensions
• wxPython 3.0.x

Your version of python must be able to build C extensions, which should be automatic in most linux and on OS X. You may have to install the python development packages on linux distributions like Ubuntu or Linux Mint.

Windows doesn't come with a C compiler, but happily, Microsoft provides a cut-down version of their Visual Studio compiler just for compiling Python extensions! Download and install it from here.

Virtualenv Setup -- Linux Only

First: download the wxPython 3.0.2.0 source.

Next, setup the virtual environment:

virtualenv /data/virtualenv/wx3

The activate script needs to be modified in order for the dynamic libraries to be discovered correctly. You can do this with a simple multi-line shell command:

cat <<EOF >> $VIRTUAL_ENV/bin/activate
LD_LIBRARY_PATH="$VIRTUAL_ENV/lib:$LD_LIBRARY_PATH"
export LD_LIBRARY_PATH
EOF

Begin using the virtualenv with:

source $VIRTUAL_ENV/bin/activate

wxPython -- Linux

wxPython is the GUI toolkit, and unfortunately it is not able to be installed using pip, so you have to compile it yourself:

mkdir src
cd src
tar xvf ~/Downloads/wxPython-src-3.0.2.0.tar.bz2
cd wxPython-src-3.0.2.0/
./configure --prefix=$VIRTUAL_ENV
make -j 8
make install
cd wxPython
python setup.py install

wxPython -- Other Plaftorms

• OS X: download the package installer
• Windows: `download and run the installer http://wxpython.org/download.php#msw>`_

Installing Omnivore -- Unix-like Platforms

Get the source from cloning it from github:

$ git clone https://github.com/robmcmullen/omnivore.git
$ cd omnivore
$ ./rebuild_enthought.sh
$ python setup.py build_ext --inplace

You'll need the git package on your system, which is available through your package manager on linux, or from the git homepage on other platforms.

My modified versions of the Enthought libraries must be checked out before setup.py will work. Because I have used a unix shell script, this won't work on windows. Until I get this fixed, you can check out a source distribution from the github releases page which has bundled all of the Enthough source.

Running the Program -- All Platforms

Once the C modules are built (the Enthought library requires a C module and Omnivore has those several Cython modules for graphic speedups), you can run the program from the main source directory using:

$ python run.py

Development

Graphics Speedups

The Cython extension is used to speed up some of the time-critical code (like repainting all the character graphics), but it is only required if you were going to debug or recompile those specific .pyx files. Cython is not needed for hacking on the python code.

Should you change a cython file (currently only omnivore/utils/wx/bitviewscroller_speedups.pyx), use the command python setup-cython.py to turn that into a C extension, then use python setup.py build_ext --inplace to regenerate the dynamic libraries.

Plugins

Omnivore is extended by plugins. Plugins are based on the Enthought Framework and are discovered using setuptools plugins.

The plugin architecture is documented by Enthought, but is not terribly easy to understand. I intend to produce some sample plugins to provide some examples in case others would like to provide more functionality to Omnivore.

Some Boring History

Omnivore provides an XEmacs-like multi-window/multi-tabbed user interface and is written in and extensible through Python. It is built around the emacs concept of major modes -- different views are presented to the user depending on the type of data being edited.

It is a rewrite of peppy (my previous editor framework), but now it's based on the Enthought Tasks framework instead of my old custom framework. (Note that even though Enthought has moved mostly toward Qt as the supported GUI toolkit, I have forked Enthought's code and extended it with better wxPython support. Only wxPython is supported as a GUI backend for Omnivore. I have attempted to submit patches back to Enthough but they have not been interested in further wx support). The architectural goal is to provide a system with low coupling in order to reduce the work required to extend the editor with new major modes, minor modes, and sidebars.

Why a rewrite of the original peppy editor?

• Simplify the code. Peppy had the ability to have any major mode in any window, but this needed a lot of code to support minor modes switching in and out as tabs changed. I got it to work and all, but the code was quite convoluted. Omnivore only allows similar major modes in a window, and different major modes require a new window. Not a huge inconvenience but saves a considerable amount of coding, so I'm happy with this tradeoff. It allows me to use the Enthought Tasks framework pretty much as-is.
• Make it easier for others to contribute. Peppy was using my own framework which had a steep learning curve. Hopefully by moving to Enthought's framework, it will have a broader appeal.
• Leverage other people's code. I wrote a lot of custom code for stuff that I needed at the time, but now there are similar packages that others support and maintain. For example, I wrote a virtual file system implementation that worked, but was a whole project in itself. In the intervening years, PyFilesystem was written, removing the need for me to use my own code.

Disclaimer

Omnivore, the Atari 8-bit binary editor sponsored by the Player/Missile Podcast Copyright (c) 2014-2017 Rob McMullen (feedback@playermissile.com)

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

Enthought License

Copyright (c) 2006-2014, Enthought, Inc. All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

• Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
• Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
• Neither the name of Enthought, Inc. nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.