Re: Hardware musings

[russotto@grace.speakeasy.net (Matthew Russotto)]

In article <453fe49d$0$15651$5a62ac22@per-qv1-newsreader-01.iinet.net.au>,
Mark McDougall  <msmcdoug@no.spam.iinet> wrote:

>I'm sure half the schemes on the Apple can be defeated by changing a single 
>byte on the disk - albeit after several hours of disassembling/tracing. And 
>you can be pretty sure there's no 'stealth' behaviour going on to content 
>with...

Not just the Apple.  At the end of the day, it's pretty common for a single
BRA or NOP substituted for a conditional branch to defeat a protection
scheme.  Sometimes they do multiple independent checks, but not that
often -- was probably actually more common on the Apple.

Although one of my favorites was a certain piece of software which
contained within it a list of pirated serial codes; that is, codes
which were algorithmically valid but which were known to have been
passed around.  It couldn't be so easy as to use one of those codes
after nulling out the list, could it?  Well, yes, it could :-)
-- 
  There's no such thing as a free lunch, but certain accounting practices can
  result in a fully-depreciated one.