

Real Life Tron an an Apple IIgs - Rusky
http://blog.danielwellman.com/2008/10/real-life-tron-on-an-apple-iigs.html

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SpacemanSpiff
from the article:

Writing to random locations in system memory isn't generally a wise design
practice. Unsurprisingly, the game would generate spectacular crashes as a
result. A human player would be driving blind and usually crash right away,
limiting the scope of system casualties. The AI opponents had no such
weakness. The computer would scan immediately in front, to the left, and to
the right of its position to determine if it was about to hit a wall and
change directions accordingly. So as far as the computer was concerned, system
memory looked no different than screen memory. As Marco described it,

 _We can only speculate what it started doing once it left screen memory,
since it obviously would look to find a way to continue going in a direction
that was occupied by 0’s. If it became blocked and ran into a “wall” of
numbers, it would die. In those spectacular crashes though, it would sometimes
be running around very much “alive” until at some point it either overwrote
some code being executed with a trail that didn’t make sense, or it would
access some memory mapped device that would then cause a crash. But it wasn’t
immediate – the AI ran around for a little while out there before it crashed
the system._

\-- Wow, thanks for this - the imagery here is great.

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spitfire
Real life core wars. Quite cool.

<http://en.wikipedia.org/wiki/Core_War>

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ralphc
Back in the day I used to have fun with my TRS-80 by hand-typing in a program
to infinitely looping poking a random value into a random memory location.
Some of the time the program would stop because it changed the BASIC source
code, sometimes it just...stopped. It was just RAM and ROM, I'd disconnect the
cassette storage before doing it, so it was harmless.

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Swizec
What I seriously wonder is, just how easy was it to write a virus in the days
before protected memory? And by that I mean a virus that could do some pretty
horrible things, I'm sure it was possible to destroy a disk or a printer or
something by making them do things they should never get up to ...

Was it that before then people simply weren't writing malicious code and
nobody even thought about safeguarding against it?

Furthermore, were banks and stuff ever running on OS's without protected
memory? Because that ... that would've been awesome in its own little naive
way.

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jrockway
Corrupting the OS's memory is rarely a problem. It's corrupting your
application's memory that's a major problem, and that's still very easy to do
on modern hardware with "modern" development techniques.

People in the finance industry treat C++ like they were abandoned as children
in the woods, and C++ brought them to its home, fed them, raised them, and
sent them to college. Someone I work with claims that Stroustrup is God.

If you're an exchange or some other data source and you want to compromise a
shit-ton of machines, start sending invalid messages to the banks. You will
have a botnet in about three nanoseconds.

