This page is about the preservation /backup for the future of Atari software stored on Floppy Disk Support. This is also related to Atari protections mechanisms used on FD as they make preservation / backup more difficult.
Most, if not all, of the Atari programs are no longer available from their original suppliers and the problem with FD support is that the passage of time degrade them. Floppy disk medias created in the 80s / 90s we are now close to end of life even if kept in good conditions. Therefore preservation becomes an urgent task.
Preservation Techniques available for Atari Users
Here I compare several software/hardware that you can use to preserve your Atari floppy disks. Things are evolving quickly in this area and therefore this comparison is a snapshot of what is available at the time of the writing (December 2014).
The first question that you have to answer is: why do I want to preserve my floppy disks?
The main reasons I can think of are:
- I want to use real floppy disks on a real Atari (floppy disk backup)
- I want to use floppy images on a real Atari (hardware emulation)
- I want to use floppy images on an emulator (software emulation)
- I want preserve for the future images of floppy disks (preservation for backup or emulation)
Comparison of different Atari “preservation” techniques / hardware devices
The following section compares several techniques / devices that can be used for preservation and/or backing-up protected FD
- Some especially design copy programs like Fast Copy Pro are able to copy some protected disks directly on Atari. However these programs are not able to copy floppy disks using sophisticated protections mechanisms. Usage floppy disk backup
- The Blitz software that uses a specific cable is able to reproduce some protected floppy disks that can't be reproduced by software only. However be aware that in most cases even if the copy works the copy is quite different from the original and therefore this cannot be considered as a preservation of the original. Usage floppy disk backup.
- Pasti is a free (but not open source) imaging software tool released on Atari. The STX image format produced by Pasti has the following benefits: it supports almost all Atari protections, it is supported by most Atari emulators (SW/HW), and most important it has been around for quite some times and therefore there are thousands of STX images available (for example from Atari ST Game Archive, or from also Atari-Mania). However the major problem is that the Pasti STX format has not been publicly released. But you can find some reverse engineering information from Markus site, from HxC site, and from P.Putnik site. I have created a detailed documentation of the Pasti file format based on reverse engineering and discussion with the author Ijor. For info Ijor has created a non-released DCPasti software running on an Atari ST that uses the Discovery Cartridge Hardware to get better information. Usage software / hardware emulation.
- The Discovery Cartridge from Happy Computers is a Hardware device that connects to the Atari ST. It comes with dedicated software that allows imaging of protected FD. You can either write images to a hard disk for preservation (but no emulator support this format) or to backup your original to another FD. This was the preferred solution in the 90s to backup floppy disks. Usage floppy disks backup.
- The KryoFlux device from KryoFlux Limited is a board that connects to a host (PC/Apple/Linux) and a Floppy disk drive. It comes with dedicated software that allow to create images of floppy disks (protected or not). The output uses the Stream format (publicly described) or the CTR format (accessible through a publicly published library). These formats can be used directly by end user (for emulation or backup) or the can be send to SPS people to produce IPF preservation files (for emulation or backup). Conversion from Stream / CTR to IPF requires complex software / process and is therefore not available to genuine users. I have created documentation for the Stream File Format and the IPF file format. The Aufit program allow convertion of Kryoflux files to Pasti STX format for emulators. Usage preservation for backup or emulation.
- The Supercard Pro device from CBMSTUFF is a board that connects to a host and a Floppy disk drive. It comes with dedicated software that allow to create images of floppy disks (protected or not). The output uses the SCP format is publicly described. This formats can be used directly by end user for backup. Usage preservation for backup. By using my Aufit program it is also possible to convert the SCP format to the Pasti STX format for usage in Atari emulators.
|
Pasti |
DC |
Kryoflux |
Supercard |
SPS IPF |
File format |
STX |
mfmbtemp |
Stream/CTR |
SCP |
IPF |
HW |
none |
DC |
KryoFlux |
Supercard |
KryoFlux |
HW Cost/Avail. |
None |
Hard to find |
90 € |
99.95 $ |
None |
SW Emul. |
All |
No |
All |
Indirectly |
All |
HxC FD Emul. |
Partial |
No |
All |
Partial |
Yes |
Producer |
User |
User |
User |
User |
SPS |
Preservation |
No |
Yes |
Yes |
Yes |
Yes |
FD Backup |
No |
Yes |
Partial |
Yes |
Yes |
Usage |
Emulator |
Backup |
E/B |
P/E/B |
P/E/B |
Notes:
- Pasti STX format can now be read by Steem / Hatari / Saint emulators. It is partially supported by by HxC floppy emulator and not yet supported by CosmosEx floppy emulator. Pasti cannot be called a preservation format, as a lot of information from original is missing. Therefore the only usage of STX files is for software / hardware emulators.
- The Discovery Cartridge is a very nice hardware if you want to make backup copy of floppy disks on an Atari. However it is hard to find and it requires to uses control script to successfully reproduce protected floppies. There are control scripts available for several hundred of protected FD in the public domain but new script cannot be added by the now dead company. Therefore the only practical usage of DC is for floppy disc backup.
- Kryoflux has been designed by SPS people to preserve floppy disks. Originally you were suppose to send Stream files to SPS people that in return would send you IPF files. The IPF format can be used to create backup disks and to be used in emulators. The use model has been simplified as it is now possible to directly use the CTR format produced by KF for emulation and partially for backup (some format not yet supported). The IPF and CTR formats are directly supported by Steem / Hatari / HxC. Therefore the Kryoflux board can be used directly for emulation and backup using the CTR format. It can also be used for preservation, emulation and backup using the IPF format but this requires to send stream files and receives IPF files from SPS.
- Supercard Pro has been designed to easily backup floppy disks. The imaging process produces SCP files that can be used directly to create backup of floppy disks. Currently the SPS format is not directly supported by software emulators. However it is possible to use my Aufit program to create a STX file that can be used in emulators. The HxC floppy emulator support the SCP format.
What solution should I use?
The solution depends of your primary usage:
- I want to preserve my games / programs for my grandchildren:
- Use a KryoFlux device to image the disks, send the Stream files to SPS, and get the IPFs back or,
- Use a Supercard Pro device to image the disks.
- Use a Discovery Cartridge to create images for duplication in the future. - I want to backup my original games / programs to play on my real Atari:
- Use DC cartridge, Supercard Pro, Kryoflux (partially) to create FD backups that you use on your Atari
- Use Pasti to create images read by the HxC FD emulator connected to your Atari
- Use KryoFlux or Supercard Pro to create images read by the HxC FD emulator connected to your Atari - I want to play my original games / programs on a SW emulators:
- Use Pasti to produce images read by most emulators (Steem / Hatari / Saint)
- Use a KryoFlux or Supercard Pro device to produce images read by emulators. Currently Supercard Pro files need first to be converted in Pasti format with my Aufit program to be used in SW emulators. - I want to play games / program that I do not own (we all know you should not do that) on an emulator:
- Use images created by others (using STX format in most cases) that you run on SW emulator (Saint/Steem/Hatari) or on a real Atari using HxC or CosmosEx FD emulator.
- I just want to create a backup FD of games / programs:
- Use DC cartridge on Atari
- Use KryoFlux (partial) or Supercard Pro devices on other platforms.
Backup / Preservation of Protected Disk
Backup Philosophy
A backup program should always do the most to ensure the integrity of the resultant copy. The copy produced should operate just like the original and not remove the protection, or modify the program being copied in any way. The backup program must do the up most to check that the copy produced is correct. Therefore analog copiers should be avoided.
Note that in order to create a backup of most Atari copy protected FDs, special hardware is required. This is because many of the protection mechanisms cannot be reproduced directly using the Atari FD controller. The only hardware solution for creating backup of diskettes (protected or not) on Atari is to use the Discovery Cartridge from Happy Computer. It uses a specially designed IC that allows to work down at the flux level when necessary and therefore can handle all possible Atari ST protection mechanisms. New KryoFlux and Supercard Pro devices, running on other platforms, have been especially designed to create backup of floppies.
There are several Atari ST FD imaging formats for non protected diskettes (ST, DIM, MSA, ...) which were mainly created for emulation purpose but can also be used to recreate diskettes (backup). There are also new imaging formats for protected diskettes (CTR, IPF, SCP) that can be used to recreate FD.
Typical procedure for duplication of protected diskettes:
- Create a disk image of the diskette using a format that can record all information including all copy protection mechanisms used by the Atari key protected diskettes.
- Write a backup of the diskette using the disk image created in the first step. As already mentioned this usually requires to use specialized hardware (at least for many protections) like the Discovery Cartridge, the KryoFlux Device or the Supercard Pro device.
Note that this duplication procedure is exactly what is used by the Discovery Cartridge backup program. But unfortunately the DC backup program requires information about the protection from the user and is therefore not fully automated.
You will find here an Excel table (without any warranty) that contains a compilation of about 950 entries of program/games diskettes and the best known way to copy them using software copiers and blitz cable.
Back to the topSoftware Copiers
The Atari TOS provide a rudimentary backup program using a simple drag and drop procedure. However this duplication only works for "standard" TOS formatted floppies and will fail for anything not standard (e.g. with different number of sector per tracks, with non standard 512 bytes sectors, etc.). This limitation (non standard layout) was used as a simple protection mechanism .
Therefore many specifically designed software copiers were developed to bypass some of the protection mechanisms. Several of these backup programs are pretty good at copying games FD that uses many "weak" protection mechanisms: AC13A, AC12E, DSAPIENS, FASTCOPY 1, PROCOPY 1.5, STARCOPY, STCOPY20, STCOPY 7.65 (you will found most of them in this archive) or the well known Fast Copy Pro. But as said before some protections like fuzzy bits cannot be copied using only software.
Back to the topHardware Copiers
As soon as an Atari FD uses more sophisticated protection mechanisms it is necessary to use a "Hardware Copier". There are two type of HW copiers:
- The analog copiers (presented on this page)
- The Digital Copiers (presented on separate pages)
While analog copiers can be used to produce working copy of protected games they do not fulfill the backup philosophy requirements as described above and therefore they should be avoided if possible. For sure they cannot be used for preservation.
Back to the topThe Blitz Analog Copier
The Blitz solution is an hardware analog copier composed of a special cable and an associated program. It is good at copying many protected diskettes, but certainly not equivalent to a digital solution like the Discovery Cartridge, the KryoFlux board, the Supercard Pro device.
Blitz presentation:
"BLITZ from AT YOUR SERVICE is a revolutionary new back-up system for the Atari ST computer. BLITZ uses ONLY a special cable and software to back-up your software at a speed and power unheard of before. There is NO internal wiring done to the computer. The BLITZ cable copies from Drive 1 out through the Computer printer port to drive 2 (You must have two drives to use BLITZ). It reads Drive 1 and writes Drive 2 at the same time. The time it takes a normal copy program to read a disk, the BLITZ reads and writes the disk in one pass. The BLITZ backs-up protected and non-protected disks in the same amount of time"...
This solution allows to backup many protected games, but fails on others. Basically the blitz solution copy the analog data from one floppy drive directly to another floppy drive without using the FDC (the floppy drives are actually controlled through the parallel interface). Therefore it is suppose to handle many protection mechanisms that play with the bit-cell timing (e.g. writing floppies with non standard drive speed, etc...). However this is not a perfect solution as it does a "blind analog copy" of the flux without performing any control or check and the process is very sensitive to drives speed and synchronization. Nevertheless it works fine in many cases even if the resulting image is certainly not a "perfect copy" (i.e. it is usually not possible to make copy of copy). If you want to try this solution you need to buy or build a BLITZ cable and use the special BLITZ program (original disk). The following archive contains other versions of blitz programs that I have collected. You will need to experiment these different versions as some works better than others for different protected diskettes (refer also to this Excel table).
What to think about Analog Copier
Here is a quote on analog copier from Fiat of the SPS project:
Although the data stored on floppy disks is digital (being computer data) it is is stored in an analogue form. In hardware copiers the computer reads the disk by interpreting the bit-cells making up the flux transitions as 0's and 1's, checks all checksums match and holds that data to be subsequently written. It is "refreshed" and so "new" every time it is written. However, in analogue copiers, there is no such buffering. They work by tightly synchronizing two drives and the signals send from one disk to another is a pure analogue signal. There is no checking of integrity (CRC, etc.), because the data is never actually "processed". This is the only practical way a consumer can try to copy protected disks and such a solution is cheap to develop and manufacture. A disk copy produced by such a process is slightly less "quality" than the master. If you keep making generational copies like this the copy gets worse until the bit-cells can no longer "hold together". Unfortunately, since it is digital data the result is that you get errors (bits are mis-read and even "bit shift", that is, corrupt neighbor bits because of their change of value), and likely the game will not work any more. The trick to understanding the above is that what is recorded on floppy disks is not just the data, there are other sorts of information too. They can copy many density protections, just as long as the timing is not too strict (for example, the Amiga version of Rob Northen's Copylock usually fails, and the ST version is quite similar). They can also copy disks with variations in disk format. However, they cannot copy flakey bits (aka weak bits). You cannot blindly image this protection, because of the way it works. See here for more information: flakeybits. This type of protection looks so far very common on the ST and PC.
Here is a quote from Ijor on analog copier :
Disk analog copiers work very similarly as dubbing an audio tape. They just reproduce the signal from the source diskette into the destination one. The consequences of this are several:
- The copy won’t be aligned to the index hole. Using matching drives from the same manufacturer will help a bit. But both drives can never be synced well enough. So any protection that relies on some kind of index alignment will fail. This includes software that can easily be copied with a software copier.
- Any “soft” (recoverable) error will be reproduced on the destination and converted to a “hard” (unrecoverable) error. A soft error happens when you read a sector and get an error, but it reads ok after a retry. “Soft” errors are much more common than what people realize. You usually never note them because there is a lot of retry logic going on at different levels of the operating system. Other type of copiers, both software and hardware, will retry on any error and will usually recover from soft errors. But an analog copier will not, it can’t because it has no way of detecting the error in the first place.
- No verification is performed. So errors produced when writing are not detected. Again, no verification is possible.
- No filtering, adjustment or pre-compensation is performed. Take in mind that we are taking about a mechanical device and a magnetic medium. The signal you read is not exactly what was originally recorded. Digital devices, such as the FDC or a hardware digital copier, perform a lot of filtering that here is not possible.
- Because no “digitalization” is performed, the signal is degraded further on each “generation” copy. After a small number of generations there is very little chance of getting a working copy. Third generation copies usually don’t work (a copy of a copy of a copy of an original). [more on signal degradation can be found here]
Personal note:
I think that the term analog copier is a bit confusing as the
interface of the FD drive is digital (i.e. TLL signal) and therefore we are not
really dealing with analog signals like it would be with an analog recorder (e.g. VCR). However, if clearly specified and understood, the term analog
is acceptable to indicate the fact that the signals produced by the head of the
reading device is not processed by a digital circuit (the FDC) but directly sent
to the head of the recording device and therefore it is not "regenerated". Due to the nature of the analog signal coming from the head the shape (and
therefore most importantly the timing) of the converted digital signal will be quite different
from the original signal and will definitively degrade during multiple copies.
But
I disagree with the fact that analog copier cannot copy weak / flaky bits,
actually they should be relatively good at that ... however as already said they do not fulfill the backup philosophy requirements.
Atari Protection References
Documents
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
- Extracts from "Looking for Rob Northen originals images" thread
- Copylock Keydisk.s
- Copylock(tm) ST - Serial No. Program for the Atari ST/STE
- Compact Disc Copy Protection - Matthew Territo
- Citizen Micro Floppy Disk Drive Specification
Forums Threads
- 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
Web Links
- 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
- floppy disk format
- PASTI Project
- DM Protection document
- Detailed analysis of the Dungeon Master and Chaos Strikes Back for Atari ST Floppy Disks
- US patent - Copy Protection for computer Disc 4,849,836
- An interview with Rob Northen
- Disk Backup Programs: Do they realy work
- SpinRight Technical note
- C64 Preservation Project (Commodore)
- Atari Disk Image FAQ
- Tim Mann's TRS-80 Pages
- MAGNETIC RECORDING
- The Central Point Option Board
- SpinRite's Defect Detection Magnetodynamics
- How to HD install Pacland (MFM format) using WHDLoad
- LIBDSK library for accessing discs and disc image files
- WinUAE Amiga Emulator
- Hard Disk Data Encoding / Decoding.
- Intel 82077AA FDC Datasheet
- Commodore C1581 - WD1770 FLOPPY DISK CONTROLLER
- PC87310 (SuperI/OTM) Dual UART with Floppy Disk Controller and Parallel Port
- The Great CRC Mystery Terry Ritter