I have created a document that describes the copy protection mechanisms used on Atari mainly from a "hardware point of view" (e.g. detail analysis of the flux transitions sampled from FD) and not from a "software point of view" (how a program tests these protections). If you are interested at the software side of the protections you can go to pages like Atari ST Protections from Markus Fritze or Les Protections sur Atari ST/AMIGA (in French) de DlFrSilver.
It is highly recommended that you first read my document Atari Copy Protection Based on Key Disk that provides detailed information about most of the floppy disk protection mechanisms used on the Atari platform.
Analysis of protections at the flux transition level has been done using my new Aufit Program as well as my older Analyzer programs. The flux transitions samples are created using the Discovery Cartridge (on Atari) or the Kryoflux and Supercard Pro devices on PC.
To look at actual analysis of games please go to my Atari Game Protection Analysis pageBack to the top
- User input based protections
This first mechanism is requesting the user to type information at the start of (and/or even many times during) the program/game. This information was provided in "documents" that were difficult to reproduce in the 90s (remember that at that time scanners, color copy, etc. where not easily available). For example the documentation could contain colored text that could only be read with special filtering glasses (red and green) or text appearing behind rotating wheels... This kind of protection is relatively cheap to produce (part of the normal documentation) and usually allow to install the program on a hard disk.
- Hardware / Dongle Protections
This second mechanism requires to use an hardware key (also called a dongle) that plugs into an Atari port: usually the cartridge port but sometimes the joystick, or parallel ports. This kind of protection is relatively expensive. It was therefore not used very much in games but was largely used by "professional" programs like musical programs from Steinberg (using dongles plugged on on the cartridge port). Normally programs protected with dongles can be installed on hard disks.
- Key disk Protections
This third mechanism uses a "copy protected disk" or "key disk". In this protection the commercial software manufacturers uses specially formated disk that can not be reproduced by a standard Atari system as a mean to protect their programs. By using special commands the software can verify that an original disk is used and not a copy. This verification is usually done at load time, and the program would refuse to run if the "protection information" was not correctly detected. The copy protection mechanisms on Atari started with simple tricks that could be reproduced by specialized copy software to end up with very sophisticated mechanism that requires special hardware (e.g. Blitz cable, Discovery Cartridge, KryoFlux ...). Note that most key disk protected programs cannot be installed on a hard disk.
For more information on this type of protection read my document Atari Copy Protection Based on Key Disk.
Note on usage of disk images for running protected programs / games with emulators:
- For protection of type 1 standard images can be used but you will need to enter the requested information like on real machine, and therefore you need to have access to the documentation used for protection,
- For protection of type 2 there is currently no solution to run these programs in emulators other than using images of cracked version of the programs,
- For protection of type 3 you need emulators (hardware or software) that run protected disk images.
- You should also know that there are a lot of images of "cracked programs" available from Internet. In this case of course the protection mechanisms are removed and a normal disk images can be used.
In the area of protection of computer disc against unauthorized copying many patents exists. Some of them are presented below as they are of interest to understand Atari protections:
- US Patent 4,462,078 Computer Program Protection Method
- US Patent 4,577,299 Hardware Key-on-disk System for Copy-protecting Magnetic Storage Media
- US Patent 4,584,641 Copy protecting System for Software Protection
- US Patent 4,734,796 Technique for Preventing Unauthorized Copying of Information Recorded on a Recording Medium
- US Patent 4,785,361 Method and Apparatus for Frustrating the Unauthorized Copying of Recorded Data
- US Patent 4,849,836 *** Copy Protection for Computer Disks - Used in Dungeon Master, Chaos Strike Back .... ***
- US Patent 5,027,396 Execution Protection for Floppy Disks
As many of the documents referenced here are difficult to find, you will find a local copy of these documents.
- Atari Copy Protection Based on Key Disk - Jean Louis-Guérin
- Introduction to Copy Protection - Serge Pachkovsky June 91
- Speedlock Macro-Dos system for Amiga
- Rob Northen Copylock Backup/Restore program v 1.00
- Interesting extracts from thread "Looking for Rob Northen originals images" on Atari forum
- Copylock Keydisk.s
- Copylock(tm) ST - Serial No. Program for the Atari ST/STE
- Compact Disc Copy Protection - Matthew Territo
- Weak Bits, Bit-rate var., data under index: Copy Protection
- Copy Protection details
- Looking for Rob Northen originals and
- Rob Northern Code Found
- Questions Regarding STT Images
- Copy II ST
- Looking for AntiBitos 1.4 by Illegal
- Most memorable Hack/crack
- Protected Disk Image Project Seeking Beta Tester
- Ideas about ST floppy image make program for PC
- Looking for DMA file under interrupt
- PASTI Project
- Mega STE Specifics
- Copy Protected Disks
- Gcopy DIM file
- ST Protection routines
- putting a second internal floppydrive in the STF..
- RamDisk and ATARI-ST Disk IO
- X-out original protected
- You should first read an article on protection "copy me I want to travel" from Claus Brod the expert who wrote the book Scheibenkleiste covering all sort of interesting details about floppy disks, hard disks, RAM disks, CD-ROMs and other mass storage devices for the Atari line. Unfortunately the book is in German and apparently out of print.
- Les Protection sur Atari ST at AitpaST site
- Atari ST Copy Protections
- Pasti File Format
- PROBING THE FDC LEARN THE SECRETS OF YOUR FLOPPY by David Small
- Atari Protected Disk Image Format & Atari Protected Disk Image Format
- Software Preservation Society (SPS) - originally Amiga but now support Atari
- PASTI Project
- DM Protection document
- Detailed analysis of the Dungeon Master and Chaos Strikes Back for Atari ST Floppy Disks
- An interview with Rob Northen
- Disk Backup Programs: Do they realy work
- C64 Preservation Project (Commodore)
- Atari Disk Image FAQ