Author Topic: Copy protections  (Read 2624 times)

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Offline Petari

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Copy protections
« on: 05-09-2011, 16:08:13 »

   Copy protections used by Atari ST SW


What is copy protected floppy by Atari ST ?  :

We may say that everything what is not standard, FAT12 format floppy, where all files are accessible with Desktop for instance. Or if format of floppy is standard then there are some extra  checkings for something not present on regular formatted floppy.

Cases of not copy protected SW:  Flight Simulator 2 (Sublogic)
   Space Quest III
   Alpha Waves -  this has so called 'Manual protection' - needs to find proper string in manual and type in.

Often, such SW is easy to install on hard disk - just copy all files into some DIR and run.

But hard disk usage was not interesting for most in 1985-1995. Instead, they cared about how to stop making illegal copies.

Simple (and inefficient) copy protections:
Only few KB on floppy used seemingly: Case of game Sundog  for instance. There is only 1 short file visible. And no hidden files. Point is that most of game data is stored on floppy in RAW sector data form, and not in regular files. Game accessing it via TOS functions (XBIOS floppy read). So, you can not copying that game by copying file(s). But it was easy to copy it with some better copy program even in 1987 - program what can copy disks by sectors, tracks. Another such is Black Cauldron ++  .

Above 2 type is also runnable from hard disk using Floppy Image Runner - there is XBIOS mapping too.

No files visible:  all data, code is in RAW sector format. Start of SW is by booting (resetting machine with inserted first floppy).
Physical format may be standard or something very special - everything is allowed what machine can read reliable.
So, we have weird sector numbers, fake track addresses, lot of data packed on track (so can not write with regular Atari or PC), missing sectors, tracks etc.

Or physical format is standard - then copying may be possible with simple copy SW.
Examples: Carrier Command (org. edition) - but it has 'Manual protection'
   
Regular format floppy (FAT12), but copy protected:
There is something extra, non-standard on disk. Often not writeable with regular HW, and copy SW.
It is usually:  unformatted track.
                       track with less sectors than others
                       sectors with CRC error, or RNF error
                       extra data (serial #) in gaps between sectors
        slower sectors (CopylocK)
        sectors with flakey bits (fuzzy)
        lot of data on track - it is actually case of 'faster sectors'

All above mentioned protection systems may appear on RAW sector based floppies too.

Latest systems can copy only with specialised HW as Catweasel, Kryoflux and similar.

Pasti successfully images practically all copy protections for ST.
There are few cases that good Pasti image works not in emulators - the reason is that very tricky code is used to prevent hacking, what emulators can not well emulate. Example: Warp - it causes bug in Steem what screws low CPU vectors (crazy code using PSG registers by jumping). Few titles can not be correct imaged with current Pasti.

Cases when copy protection prevents legal usage:  it is not rare that some SW will not run on TT, Falcon, Mega STE just because of copy protection - cracks may work. Example:  Dungeon Master (TT, Falcon).
Or all later Copylock protected floppies with regular files and not bootloaded, so starting with AUTO folder or by clicking in Desktop. They will fail under TOS 2.06 (Mega STE) or later ones, because there is CRC error in sector 6 on trck. 0 - what older TOS versions read not by opening disk. Examples: Millennium 2.2, Voyager .