
Can a USR command damage a ZX Spectrum? - Razengan
https://retrocomputing.stackexchange.com/questions/2261/can-a-usr-command-damage-a-zx-spectrum
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floatingatoll
In summary: No, but certain port behaviors can be toggled between two states
in a little-understood manner.

Relevant quote from the top answer by the author of the video and article
below:

> _The first video shows what happens if the "randomize of the death" is
> issued to a real Inves Spectrum+. The video starts with a power cycle to
> initialize the Inves. If you can, compare this with the result obtained with
> Spectaculator running the Inves ROM:_

> _Link to video showing an Inves Spectrum+ executing BORDER 5: RANDOMIZE USR
> 4665_

FLV video:
[http://www.zxprojects.com/images/stories/videos/rand_usr_466...](http://www.zxprojects.com/images/stories/videos/rand_usr_4665_inves.flv)

> _Well, I think that after seeing this, it 's the end of the "randomize of
> the death" hoax._

Details, including the port behavior, are here:
[http://www.zxprojects.com/inves/](http://www.zxprojects.com/inves/)

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stevenwoo
But you can kill a Commodore Pet with a poke, we had those Pets in our high
school programming class in the 1980's.

[https://en.wikipedia.org/wiki/Killer_poke](https://en.wikipedia.org/wiki/Killer_poke)

[http://www.6502.org/users/andre/petindex/poke/index.html](http://www.6502.org/users/andre/petindex/poke/index.html)

~~~
ksaj
The PET's killer poke made the text on the screen look like it was wrapped
around a cylinder. The damage it could cause was screen burn in along the
left-most and right-most columns because they were at maximum brightness,
while the rest of the text was less bright and quite stretched out.

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peterclary
The BBC Micro B had a physical internal relay which controlled cassette tape
player motors. The following program (from memory) would produce an alarming
buzzing which, if left long enough, purportedly led to the relay wearing out,
i.e. physical damage.

    
    
        10 *MOTOR 1
        20 *MOTOR 0
        30 GOTO 10

~~~
gambiting
I mean, CD/DVD based games consoles have the drive rated for only a certain
number of reads, there is an interview with Naughty Dog devs talking about
development of Crash Bandicoot, where apparently they discovered that on
average playing through the entire game would do a "lifetime" of reads, Sony
allowed the game to be released anyway(and it looks like the drive was under-
rated if anything, since no significant drive breakages were reported from
playing this game).

I do however know of one Gamecube game which was an inch away from being on
the market in a state that would brake the drive of every gamecube that played
it - some very clever person found an undocumented command that would increase
the speed of the drive, leading to super quick streaming from the drive,
resolving some loading issues that the game had at the time. It worked well,
the game was finished and went into manufacturing, and fortunately Nintendo
realized that it's no coincidence that QA's and their own test kits keep
breaking after playing the game, and pulled it before it hit the shelves.

~~~
pj1115
That's great. Any articles about the Gamecube issue? I can't find any info.

~~~
gambiting
No, and unfortunately you won't find it anywhere since it was an internal
issue. I'm intentially avoiding naming the game as I don't think this was
publicized anywhere before.

~~~
ComputerGuru
It was indeed written about at length from one of the developers.

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tedunangst
> Once ago we told you that it was impossible to break a computer by issuing
> commands from the keyboard. Well, this would be the exception that proves
> the rule.

Or efivarfs.

~~~
zozbot234
Modern mobile SoC's can probably be hard bricked even by accident. Run a
kernel image that is not intended for the _exact_ model of your hardware, and
you incur the risk of e.g. misconfiguring some voltage regulators and trashing
some arbitrary part of the SoC beyond recovery. (And the whole thing a huge
mess because the patched kernel code is often the _only_ kind of hardware
documentation that's actually available for the SoC - hardware designers work
_directly_ on the kernel support, and implement all sorts of horrible,
undocumented hacks in the process. Though I can only assume that the recently-
mainlined SoC's and the IoT-ish designs that are being repurposed by the likes
of Purism are somewhat better from that POV.)

~~~
detaro
Configuration (including boot or memory setup, crypto keys validating
firmware, ...) also is sometimes in write-once fuses you can set from
software.

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trollied
Halt and Catch Fire.
[https://en.wikipedia.org/wiki/Halt_and_Catch_Fire](https://en.wikipedia.org/wiki/Halt_and_Catch_Fire)

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growlist
I seem to recall that pulling out a joystick connector from a joystick port
whilst the Spectrum was switched on could permanently damage both the joystick
and the computer! Though there might have been an edge connector peripheral in
there somewhere depending on the model.

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myrandomcomment
There was an original Commodore PET that could be damaged by a POKE command.
They fixed it quickly.

