General	Audio-CD	Analog	Consoles	Storage	Obsolete
Ebook	Concepts	Software	Transmission

Obsolete technologys

Some copy protection is surprisingly old, but those arn't often seen. I have moved all those over to their own section of the site here. You will probably never have to deal with any of these, but its always worth knowing about them just in case you have to break one, or just because of the intresting history.

Videocrypt	Moved.
Amstrad CPC-series tape	Remember the old computers with 64 or 128 k of ram and programs on audio casette? Those had copy prevention technology in too! Obviously you will never come across this unless you collect obsolete museum-piece computers like I do, but its intresting history. The amstrad CPC464 and CPC6128 computers loaded programs from tape, through the 6128 had a disk drive as well. The copy prevention on the tapes was a flag which marked programs for immediate execution only. Those programs could not be loaded without running, and could not be exited without clearing the memory. As the programs were on audio tape they could be copied quite easily with a double casette deck, and many people had a lot of fun fine-tuneing bass and treble knobs to copy borrowed tapes. These copys got unreliable after a few generations through. (set the base slightly lower than treble to copy :-)) The aim of the flag seemed to be more to prevent reverse enginering than preventing copying. The 6128 had a 6MHz Z80 processor. Good programing needed to be done in asm, so all commercial software was written in it and most good hobbyist programers knew it too. Obviously those hobbyists couldn't be allowed to see the copyrighted code in those programs, through I cant see why there would be a problem with hobbyists studying code. I doupt the flag would have been much good against competitors with skilled programers and hardware reference books stealing code, but back then there wasn't much competition. In my three drawsful of tapes I only have games from three manufacturers. Althrough its hard to find technical information on such an old format I have heard references to a skillfully-coded program which copied tapes to ram and rewrote them, regenerating nearly-degraded copies. Half of my CPC games are now degraded with time, most of them are dated 1986. I am busy transfering them all to PC now. Hopefully this is legal. The software will be probably copyrighted until after im dead, but half the companys no longer exist and noone is selling these games outside ebay anyway. An alternative form of copy protection was to increase the baud rate to a dangerous level. These tapes would rarely copy correctly on an analog player, but the origionals tended to degrade easily over a few years.
Atari	Various forms of copy protection were used for the Atari computers. Most involved damaging the disk in various ways either soft or hard. One particually extreme solution used a laser to burn the disk during manufacture. In turn, various copying programs to get around these schemes started circulating. The best known was X-Copy (no rlation to the modern DVD copying program). I dont know where you can get this through. According to an old atari magazine, there was a version of x-copy 8.5 of size 66424 bytes precisely that contains an early virus named Eleni, which does something nasty to your hard drive if fitted. This message was dated early '94.
The CPTWG protection	The RIAA website news archive mentions a protection system devloped by them and the CPTWG in 1997 (http://www.riaa.com/news/newsletter/press1997/013197.asp) for audio CDs. It looks like its based on a do-not-copy flag. The flaw was simple enough: The RIAA declared that all CD recorders must respect this flag, and expected the entire international technology industry to obey. Unsurprisingly, that didn't happen, and so the system was never properly implimented. If it had been, it could have been broken easily. When using nero to copy a commercial CD I notice it displays a "CD is copyrighted" warning, but copies anyway. I suspect that may be the flag, which nero displays but does not obay.
Blue manuals	An example of how a completly ineffective protection system can continue to be used out of sheer force of habbit. Remember the days when a game would occasionally ask for "the first letter of word x, line y on manual page z"? Ok, thats understandable. A floppy can be copied easily, but copying a manual is harder, and back in those days you couldn't just get a crack off the 'net. Then there were the symbol tables. A card with a table of symbols. Now the request is "which of these symbols appears in row y column x?". Of course anyone could copy that by hand, so what was the point? I remember playing transartica. I spent days tradeing and trying to work out how to follow the story, then the game asked for a symbol table. I had brought the game legally, but had no table. It was only years later that I accidentially discovered the location of the missing paper, tucked inside the double-folded CD label. Those papers were often printed in blue ink, which confuses photocopiers. Apparently the drums are most sensitive to blue, probably because of the higher energy levels, so a strong blue reflection on a copy is indestinguishable from white. I find it quite intresting that early photocopiers could only produce blue output (the origin of the term blueprint, one of two rumored anyway) and blue is now used to prevent copying. I have considered createing a list here of tables for old games, theres always a few people who lose their cards and cant buy replacements for games so old, but I cant be sure every table for a game is the same. They might vary by region or release. If anyone can give me more information on that, contact me please. Anyone who has one of those tables (games using them include "the even more incredable machine", "transartica" and an old atari version of "pipe dream", possibly under another name) send them anyway, once I have enough I can list them all here.
liquid audio	This is a failing audio protection technology, with a history of alternating suscess and diaster. Its stock price was been riseing and falling erraticly from when it was founded in 98 until its edventual demise. Althrough liquid was once the leading DRM solution for audio it has now been surpassed by WMDRM. I have compiled a history of the company from news sites.