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From: cs161fhn@sdcc10.ucsd.edu (Dennis Lou)
Newsgroups: comp.sys.ibm.pc.hardware
Subject: Re: Wild claims about copy protection--true?
Message-ID: <13445@sdcc6.ucsd.edu>
Date: 22 Oct 90 01:06:33 GMT
References: <5946@nisca.ircc.ohio-state.edu>
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In article <5946@nisca.ircc.ohio-state.edu> smsmith@hpuxa.ircc.ohio-state.edu (Steve Smith) writes:
>I had a conversation/argument with a guy last night who claimed he
>had fried a monitor and several hard disks when he was trying to
>bypass the copy protection on floppy disks at various times.
...
>Has anybody heard of such a thing?  And IS there even a way to write
>codes which could do either of these destructive things?  (And could
>one accidentally destroy hardware by tinkering with programs--even
>when it's their own fault?)  It sure sounds bizarre to me.

Yes, you can fry a certian monitors by sending odd frequencies to
it.  The solution, of course is to use a multisync monitor.
Monochrome monitors are the ones that susceptible, but damage is
usually not instantaneous (speaking from personal experience).

As for disk drives, yes you could conceivably misalign the heads by
moving the stepping the head positioner beyond range.  The hard disk
is supposed to not let you go beyond its preset maximum number of
cylinders (on the dip switches or in CMOS (for AT's and above)), but
floppies can step up track numbers infinitely.

The following peice of code will move the head beyond range
indefinitely, thus causing a theoretical misalignment of the heads.
It will probably take a while to misalign though; I wouldn't expect
instantaneous results...

from the c:\ prompt, run debug, then type:

a
xor ax,ax
mov bx,ax
int 13
push ds
pop  es
mov ah,02
mov al,01
mov ch,ff
mov cl,01
xor dx,dx
int 13
jmp 100

ntrshdriv.com
rcx
100
w

trshdriv

and there, your drives should be trashed after a while, but it will
probably be a long while (I'm NOT speaking from experience; your
mileage may vary).

Any serious hacker/cracker would catch attempts to damage equipment
like this before any serious damage would occur (either that or I've
been very lucky in the past...)


-- 
Dennis Lou            | "But Yossarian, what if everyone thought that way?"
dlou@ucsd.edu         | "Then I'd be crazy to think any other way!"
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dlou@ucsd.BITNET      cs161fhn@sdcc10.ucsd.edu