AppleWin/help/ddi-copy.html
2006-07-08 15:41:03 +00:00

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<title>Copy Protected Disks</title>
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<h2><font color="#008000">Copy Protected Disks</font></h2>
<hr size="4">
<p>The process of transferring disk images is complicated by the fact
that much of the software published for the Apple II was copy protected.</p>
<p>Software publishers have
always looked for
ways to prevent people from making unauthorized copies of their
software. Today, when you buy a game, it might ask you for a word
from a random page of the manual, to ensure that you have
purchased the game (complete with manual) and not just copied the
disk. Back in the days of the Apple II, publishers were much more
direct: they simply tried to make it physically impossible to
copy the disk. </p>
<p>Unlike the PC, the Apple II
had to perform
much of its disk encoding in software. If programmers wanted to
get tricky, they could bypass the operating system and do their
own encoding, possibly changing the size of the sectors on the
disk or the way in which the sectors were identified or stored.
This prevented standard operating systems like DOS, along with
their standard copying utilities, from accessing the disk. </p>
<p>However, programs which were
copy protected
in this manner could still be copied with more sophisticated
"nibble copiers", which copied each track on the disk
bit for bit, rather than copying a sector at a time. Similarly,
to get a program like this to run under AppleWin, all you need to
do is make a nibble image of the disk. </p>
<p>After nibble copiers became
prevalent on
the Apple, some software publishers developed tricky new ways of
creating disks that even nibble copiers could not copy. It is
unlikely that such a disk could be successfully transferred into
a disk image. </p>
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