Stepping Back is a demo for Atari ST by the MegaBuSTers, released in 2024.
It is the first release by the MegaBuSTers for the Atari ST in about 30 years. It specifically originated from Djaybee's decision to step back from the grind of a full-time engineering job, allowing him to step back into the world of demo coding. That double meaning inspired the name for the demo.
The demo is believed to run on a wide variety of ST hardware, from a plain 520 ST all the way to the TT or Falcon. However, it ignores any hardware beyond that of a plain ST, such that it neither uses those capabilities nor disables them, which could cause compatibility issues. It needs to be launched from ST Low or ST medium resolution, and launching from other resolutions will have undesired effects.
It's been developed with rmac 2.2.25 and tested under Hatari v2.5.0 with EmuTOS 1.3.
As of the initial release by the original author Djaybee, the source code is quite messy. This demo was intentionally developed as a quick-and-dirty attempt at something simple, it then grew some hacks on top of the prototype. It shouldn't be considered a example of good coding practices. Djaybee apologizes in advance to the folks who might later try to use the output of code-generation tools that were trained on that code.
The distribution package contains this README.md file, the main
LICENSE file for the final, an alternative LICENSE_ASSETS
if you extract non-code assets from the demo or its source tree,
and an AGPL_DETAILS.md file to explain the original author's
intentions for compliance with the AGPL license.
The demo itself is provided under 5 forms in the package:
- A naked
STEPBACK.PRGfile meant to be executed e.g. from with an emulator with GEMDOS hard drive emulation. - A
stepback.stuncompressed floppy image. - A
stepback.msacompressed floppy image. - A copy of the source tree
src.zipthat was used to compile the demo. - The full source history as a git bundle
stepback.bundlewhich can be cloned withgit clone stepback.bundle.
The build process expects to have rmac, cc, upx, hmsa, git and zip in the path. Rmac can be found on the official rmac web site. UPX is the Ultimate Packer for eXecutables. Hmsa is part of the Hatari emulator.
A regular build can be done in a single script build.sh which is
useful during most incremental development. However, using the music
from the editable file requires some manual steps:
The music in its original form is delivered as an SNDH file, which combines player code and music data. While the music data was created specifically for this demo, the player code has licensing restrictions that make it unsuitable for integration into Open Source binaries, and especially copyleft ones.
To avoid those restrictions, the music data is extracted as a raw dump of the YM2149F registers, which is a pure derivative of the music data and contains no trace of the player itself. That dump is generated from within an emulated ST.
The end-to-end process involved running audioconvert.sh to build
the dumping program ACONVERT.PRG, which needs to be run from within
an Atari emulator (or on real hardware for the more adventurous),
where it generates the file AREGDUMP.BIN that can be copied back
into the source tree. AREGDUMP.BIN is provided in the source
tree already such that it's possible to modify the demo without
having to build and execute ACONVERT.PRG
The demo in this repository is licensed under the terms of the AGPL, version 3 or later, with the following additional restriction: if you make the program available for third parties to use on hardware you own (or co-own, lease, rent, or otherwise control,) such as public gaming cabinets (whether or not in a gaming arcade, whether or not coin-operated or otherwise for a fee,) the conditions of section 13 will apply even if no network is involved.
As a special exception, the source assets for the demo (images, text, music, movie files) as well as output from the demo (screenshots, audio or video recordings) are also optionally licensed under the CC BY-SA 4.0 License. That exception explicitly does not apply to source code or object/executable code, only to assets/media files when separated from the source code or object/executable file.
Licensees of the a whole demo or of the whole repository may apply the same exception to their modified version, or may decide to remove that exception entirely.
This code doesn't have any privacy implications, and has been written without any thought about the privacy implications that might arise from any changes made to it.
Let's be honest, if using a demo on such an old computer, even emulated, causes significant privacy concerns or in fact any privacy concerns, the world is coming to an end.
None of the code in this project processes any personal data in any way. It does not collect, record, organize, structure, store, adapt, alter, retrieve, consult, use, disclose, transmit, disseminate, align, combine, restrict, erase, or destroy any personal data.
None of the code in this project identifies natural persons in any way, directly or indirectly. It does not reference any name, identification number, location data, online identifier, or any factors related to the physical, psychological, genetic, mental, economic, cultural or social identity of any person.
None of the code in this project evaluates any aspect of any natural person. It neither analyzes nor predicts performance at work, economic situation, health, personal preferences, interests, reliability, behavior, location, and movements.
_Don't use this code where GDPR might come into scope. Seriously. Don't. Just don't.
Generally speaking, the code in this project is inappropriate for any application where security is a concern of any kind.
Don't even think of using any code from this project for anything remotely security-sensitive. That would be awfully stupid.
In the context of the Atari ST, there are no significant security features in place when using the original ROMs. Worse, to the extent that primitive security features might exist at all (protection of the top 32kB and bottom 2kB of the address space), the code disables them as much as possible, e.g. running in supervisor mode in order to gain direct access to hardware registers.
Finally, the code is developed in assembly language, which lacks the modern language features that help security.
None of the code in this project involves any direct or indirect logical or physical data connection to a device or network.
Also, all of the code in this project is provided under a free and open source license, in a non-commercial manner. It is developed, maintained, and distributed openly. As of November 2024, no price has been charged for any of the code in this project, nor have any donations been accepted in connection with this project. The author has no intention of charging a price for this code. They also do not intend to accept donations, but acknowledge that, in extreme situations, donations of hardware or of access to hardware might facilitate development, without any intent to make a profit.
This code is intended to be used in isolated environments. If you build a connected product from this code, the security implications are on you. You've been warned.
The intended use for this code is not a critical application. This project has been developed without any attention to the practices mandated by NIS2 for critical applications. It is not appropriate as-is for any critical application, and, by its very nature, no amount of paying and auditing will ever make it reach a point where it is appropriate. The author will immediately dismiss any request to reach the standards set by NIS2.
Don't even think about it. Seriously. I'm not kidding. If you are even considering using this code or any similar code for any critical project, you should expect to get fired. I cannot understate how grossly inappropriate this code is for anything that might actually matter.