CASE HISTORY # 11
      by the Disk Doctor


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Copyright (C) 1988,  the Disk Doctor.

First published in the Rochester (PC)^3 News:
  Picture City PC Programming Club
  PO BOX 20342
  Rochester, NY 14602
The Disk Doctor may be contacted at this
address, or via CIS [73147,414].

This material may be reproduced for internal
use by other not-for-profit groups, provided
this copyright notice is included.
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10:44am
I jumped when K. tapped me on the
shoulder.  I hadn't heard him walk in,
I was so absorbed in concentration.

"Doc, you've got to help me.  I just did a
dumb thing."

I rolled my eyes.  How many times had I
heard that before?  Computers would work a
lot better if we didn't have people
operating them...

"I erased the program on my system disk.
Can you show me how to get it back?"  He
handed me the disk.

ThinkTank, version 2.  I use that program
myself.  "How did this happen?" I asked.

"Well, I wanted to free up some space on
this disk, to make room for the Sidekick
program.  I went to erase the 2 sample
files - TANK.DB and TANK.SAV - but I
accidently deleted TANK.EXE as well."

"Don't tell me....  you typed 'ERASE
TANK.*' ? "

"That's right."  K.'s eyes dipped, as if
he were dimming his headlights.  "I feel
like such a jerk.  And I know it's not the
first time I had to come to you to bail me
out."  Back on high beams, he professed
with conviction, "But I know if anyone can
help me, you will.  Is it possible to un-
erase this file with Norton Utilities?"

"Probably,"  I nodded my head.  "But the
solution is much simpler and quicker than
that.  I'll just copy my TANK.EXE program
on to your disk."  I pulled my original
ThinkTank disk from the drawer.

"But you can't do that!  ThinkTank is
copy-protected..."  He stopped, glaring at
me in surprise.  "Doctor!  I can't believe
it!  You're not going to use one of those
copy-buster programs, are you?"  He looked
like a kid who just learned the truth
about the Easter Bunny.

"Oh no,"  I cast off his dirty looks.  "I
have no use for those play-things.  No,
I'll use just a simple COPY command, and
we can restore your legitimate copy back
to working order."

"I don't understand how you can do that."

"The copy-protection mechanism used here
is tied into the way the disk is
formatted, not the program itself.  The
copy-protection isn't affeected by the
ERASE command (just be sure you never
format this disk by accident).  As soon as
I put the program TANK.EXE back on this
disk, you should be all set."

"But what's to stop you from making as
many copies as you want?"

"This copy-protection scheme allows you to
make copies, to your hard disk, for
example.  You just can't EXECUTE a copy
without this key disk."  I held up his
diskette.


10:48am
After copying the file, I switched to
drive A: and entered the TANK command.
The ThinkTank screen came up on my
monitor.  "See.  It works."

"Doctor, what can I say?"

"Just say 'TANKs'."

"No, really.  I'm forever in your debt.
Not just for this one time, but for all
the help you given us all."

"Oh, it's no big deal.  Once you
understand how these things work, you
learn how to avoid minor problems like
this."

"Boy, you must be the brightest guy alive.
You know this stuff inside out.  There's
probably nothing you don't know about this
disk stuff, right Doc?"  K.'s faith in his
childhood hero was restored.  "I bet you
could even bust into these copy-protected
programs, if you wanted to, couldn't you?
Huh?  Couldn't you?"

I paused before responding, and looked K.
straight in the eye.  "Truthfully," a
melancholy tone had entered my voice,
"The answer is yes.  But with this
knowledge, I have taken an obligation to
use these skills only for good."

K. fell silent.

The fan on my computer was unusually loud.
"Indeed, there was one of our order who
who could not resist the temptation.  He
was extremely gifted, and would have been
a great teacher!"

"Now, he serves evil, writing virus
programs in his spare time.  Ever since he
turned ...  to the dark side."  We both
sensed the light in the room had dimmed a
shade.  "Perhaps you have heard of him?"
I asked of K.

K. stepped back, as if the mere mention of
this name might be infectious.  "Are...
are you talking about ..."

"That's right,"  my throat tightened as I
spoke that horrid name, "...Disk Vader."