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HISTORY OF COPY PROTECTION

Author's Note: The following article was written for submission to ComputerFun
magazine.  Alas, the mag died!  Some information, specifically that about
pirates and piracy, is somewhat biased, due to the intended audience.  Keep
that in mind as you read this.  Still good for a laugh tho!             -dt


             COPY PROTECTION: A HISTORY AND OUTLOOK

        Back in the last seventies, when personal computers were just starting
to catch on, a lot of software was distributed on audio cassettes.  The price
was generally low ($15 and under), and so was the quality.  Personal computer
owners knew that audio cassettes could be duplicated fairly easily with two
decent-quality tape recorders.  However, the process was time-consuming and
unreliable (volume levels were critical), and it did not save that much money,
since the cassette alone cost five dollars anyway.  The market for cassette
software was stable.

        As the prices of home systems continued to drop, the popularity of the
floppy disk as a storage medium increased so that software suppliers had to
carry each program on both tape and disk.  Typically, the disk version cost
slightly more, due to the higher cost of the disk itself, and the fact that
disk drive owners were prepared to pay a little extra for a program that loads
several times faster.

        These software prices, still relatively low, were short-lived.  Disks,
unlike tapes, were trivially easy to copy.  User clubs formed in which one
copy was purchased (legally) and copied (illegally) for everyone in the group.
Worse yet, schools and businesses owning more than one system would make
copies for all of their systems from one original.  Then, individuals
connected with the schools or businesses would copy the disks for themselves,
for friends, for their user club, for other schools and businesses...  Piracy
had spread like a cancer to ridiculous proportions, throwing a monkey wrench
into the once-stable software market.

        The software distributors' next move was to modify their program disks
in such a way that they could not be duplicated by conventional means, and to
raise their prices somewhat.  These early efforts at copy-protection were very
simple, and equally simple to undo.  Every disk has on it a list of what data
is contained on it, where on the disk it is, what type of data it is, etc. 
The part of the disk that contains this information is called the catalog or
directory of the disk.  On copy-protected disks, the catalog was altered
slightly in format, moved to elsewhere on the disk, or omitted entirely.  All
someone would have to do was restore the catalog, an easy task if you know
what you're doing, and the disk would copy normally.

        The new copy-protected disks kept a significant proportion of the
pirates discouraged, much the same way a flimsy doorknob lock "keeps an honest
man honest".  Most of the early large-scale piracy stopped.  Businesses and
schools could not afford the time required to duplicate the disks, so they
shrugged, gave in and bought the disks.  Hobbyists quickly found ways to copy
the new software, but they were working independently, and therefore not
dangerous.  The software industry was content and hopeful.

        It was a false hope.  As the popularity of personal computers
continued to escalate, hobby users banded together more and more.  Some broke
the software "lock" and made the disks copyable while others purchased the
tape versions of software and transferred them to disk.  The industry
retaliated by discontinuing most of the taped versions of software, as they
were far too easy to copy, and by using more sophisticated techniques to
protect the disks.  Of course, they also raised the prices.

        These second generation copy-protection schemes worked remarkably well
for a while.  Data on a disk is encoded (pre-nibbilized) in a standard way
before it is written out to disk, and then decoded (post-nibbilized) as it is
read back.  By altering the code under which the data is written and read, the
software companies rendered ordinary copy programs useless.  Another technique
of this era was to write data in unusual formats in odd places on the disk,
such as between two tracks or after the last track normally used.

        The hobby users, indignant at the recent price increase, adapted the
general attitude that piracy is okay because they would never buy the software
at the exhorbitant price being asked.  User clubs were now considered
essential.  To not belong to one was to be repeatedly "cheated" when buying
software.  No matter what copy-protection methods the software people tried,
the pirates broke the disk and circulated the copy, quite literally around the
country.

        In order to make piracy easier, enthusiasts and certain software firms
(considered traitors by other software firms) developed special copy programs
which analyzed the data being copied as little as possible, attempting to copy
as directly as is possible from one disk to another.  The infamous Locksmith
and the more recent COPY ][ are examples of such programs, called bit copiers
or nibble copiers because they copy the data one bit or one nibble at a time,
rather than one sector or one track at a time.

        Still, the goal of a pirate was downright unprotection, not
duplication.  To a new breed of pirate, it was a game.  Each new disk provided
the pirate with a new challenge, a puzzle, which, if he could solve, would
make him famous (pirates tended to leave their mark on the disks they
unprotected in those days).  To the software firms, it was hardly a game, it
was a war of attrition, and until they could outsmart the pirates, they would
just have to increase the prices and hope for the best.

        Or would they?  Some software companies stepped back at this point and
surveyed the situation:  they probably could not keep the pirates at bay for
long, as there was genuine intelligence out there -- thousands of users all
working toward one goal -- to break that disk!  It seemed to them that they
actually had a number of options if they wished to continue to do a healthy
business.  First, they lobbied for stricter copyright laws and won.  Bootleg
disk distribution is now more illegal than every before, but it is still
difficult to enforce the law.  Second, they could fight it out, raising the
prices as necessary and developing more diabolical methods of copy-protection.

        Only so much can be done to protect disks, however.  Those firms that
continued to protect their disks were upset by the introduction of a hardware
device developed by pirates and later marketed which allows the entire state
of the computer to be frozen and remembered, down to the last status bit, and
restored at will later.  Duplication of the program disk was no longer
necessary.  The whole program was right there in memory waiting to be run. 
All the pirate had to do was duplicate the state the computer was in, not the
disk that got it there.

        The software firms, to work around the setback, tried a new technique:
they caused their programs to look at the disk periodically and make sure it
is the original.  How to tell the difference between the original and a copy
was an ingenious trick called nibble counting.  When disks are copied, the two
drives doing the copying are seldom running at the exact same speed, so the
duplicate disk will contain tracks which are slightly longer (more nibbles) or
shorter (fewer nibbles) than the original.  The software could count the
nibbles and determine whether the disk being used is an original.  Soon,
though, nibble copiers began to allow the user to preserve the nibble count,
foiling the protectors again.

        Another particularly devious tactic in copy-protection is called
sector skewing.  To simplify a complex process, data is spread finely over the
entire disk, so that it would take an exceptionally high-quality disk drive to
write such a disk, though any drive can read it under direction of the
software.  What these software firms realize too late is that the pirates have
one secret weapon -- a foolproof, though painful, procedure to break any disk
protection scheme -- boot tracing!  You see, software has the unfortunate
characteristic that it has to be written in such a way that the computer can
understand it.  It has to, so to speak, spoon-feed itself to the computer. 
The process of boot tracing is simply to painstakingly, step by step, pretend
you're the computer, follow all the rules it follows, and you will eventually
succeed in reading the disk.

        Some software firms still fight the war of attrition, such as
Br0derbund, On-line systems and others.  Other firms had a better idea:  to
give up on protection altogether and direct their attention to providing an
attractive package -- with ample documentation, quick-reference cards and
other goodies -- at a good price.  An excellent example of this novel
approach, to give the buyer a good deal, is Beagle Bros, whose software has
never been protected, and never will be.  Their products are of highest
quality and reasonably priced.  To be sure, it is duplicated to some degree,
but the package with all its goodies is worth the investment.  Penguin
software has used this approach successully as well.

        A final possibility, useful only in the more expensive packages, is to
require a hardware device to be installed in the computer for the software to
run properly.  Softerm 2 for Apple, for instance, requires a plug-in card to
be installed in the computer which has attached to it three special function
switches necessary for the operation of the program.  You can copy the disk,
but not the card.  Not all computers have as much room for extra hardware as
the Apple, though, and hardware devices cost a lot of money compared to disks
and manuals, so this method is only practical in expensive packages.

        So where does all that leave you, the honest (ahem!) consumer?  Well,
the software firms really are anxious to serve you.  If your copy-protected
disk ever fails to work, you can send it back for free replacement.  If the
disk is damaged physically, the replacement fee is about five dollars
(provided you send in the old disk!!).  Many packages come with two copies of
the software, in case one should fail, and legitimate software owners often
receive free updates to both the software and the documentation.  Software
companies try to make it worth your while to buy their product.  Also, due to
a recent crackdown, big-time pirates are getting caught, and piracy is more
anonymous now.  Trust among pirates has broken down, and so has the once
widespread circulation of pirated disks.  The heyday of piracy is over.  So,
if you are thinking of getting some software, examine the package.  Find out
exactly what the program can do, the guarantee, and all the fringe benefits
you will receive as a legitimate owner of the software.  If, after all that,
the package does not interest you, don't buy it.  If you are considering being
a pirate, be careful!  Imprisonment is entirely possible if you are caught,
and even if you are not, you are only raising software prices for yourself and
everyone else.

                                        -DT