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 Post subject: Best comments found in code EVAR.
PostPosted: Wed Feb 25, 2009 9:28 pm 
Coppermine
Coppermine
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Joined: Sun Nov 13, 2005 2:24 pm
Posts: 603
Location: The other side of zero.
"What are you doing looking at this?"


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 Post subject:
PostPosted: Wed Feb 25, 2009 9:29 pm 
Monkey Fed [PC]
Monkey Fed [PC]
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Did you hit new topic instead of reply??


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 Post subject:
PostPosted: Wed Feb 25, 2009 9:56 pm 
Coppermine
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Location: The other side of zero.
No, I wanted to comment on the "Zombie" thread below. And starting a new topic seemed to be the lesser of 2 evils.
*edIT*
On the older platform, code was sometimes boolean manipulated to scramble it from prying eyes.

So I would run a routine simmilar to this on it.

ldx #$00
start
lda data (start of memory encrypted.)
xor a,x
cmp #$78 (check for "Set interrupt flag.)
beq found
inc x
jmp start

data (encrypted code here.)
found ((end (check x-register for decrypt code.))
(The above might be a bit mixed, but hopefully the idea will come across.)

Exploiting the fact that "proper" coding demanded that the "sei" was always the first line made it easy to view/descramble the old code.

Granted it's been about 25 years since I used this to rev. eng. (Programmers used to leave some nasty messages.)


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 Post subject:
PostPosted: Thu Feb 26, 2009 5:09 am 
SON OF A GUN
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This is even worse dude...

That other thread was already resurrected. In that case you should use what is already there....

(Then again, I am of the thought that if there is a thread that exists already you should use that one, old or not. But I don't make the rules :) )


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 Post subject:
PostPosted: Thu Feb 26, 2009 5:20 am 
Java Junkie
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The other thread has already been resurrected. This was a very stupid thing to do.


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