Why is it an "illegal operation?"

[amadeus]

I'm trying to find the genesis of this particular computer term, since some technologically illiterate people in the past have been convinced that performing an "illegal operation" means that they've broken the law.

Does anyone know why it is termed an "illegal operation?"

Thanks!

 

[Lone Wolf]

In Russian versions of Windows, it's translated as "unallowable operation", as in "operation which is not allowed".

 

[amadeus]

I'm guessing "illegal operation" would have only been used on Soviet computers.

 

[Padma]

An "illegal operation" usually means the program is trying to do something it shouldn't, like writing outside of its own data space.

 

[ParadigmShifter]

In Soviet Russia, operation disallows you!

Seriously though, Padma is correct, reading/writing outside your address space or attempting to execute a privileged instruction in user mode (i.e application code rather than system/driver level code).

Most of the time it is accessing an address through an uninitialised or zero variable.

 

[amadeus]

An "illegal operation" usually means the program is trying to do something it shouldn't, like writing outside of its own data space.

I know what an illegal operation is, I was wondering why the term "illegal" came to be used.

 

[aimeeandbeatles]

I tried googling "origins of illegal operation" and on the third page or so, I got "free illegal operation download." When I tried clicking on it just to see what it was, it warned that it might be malware.

Also reminds of of something I read, about this woman evacuating her house because her new Mac showed a bomb (for the error message) and she thought the computer was gonna blow up.

When I first started using the computer when I was 5, and got it for the first time, I asked mom when the police were going to come.

 

[ParadigmShifter]

It just means it is not allowed, not that it is against the law.

What do you call a move in chess where you move your pawn 3 squares forwards and one to the side?

 

[Padma]

I know what an illegal operation is, I was wondering why the term "illegal" came to be used.

Like ParadigmShifter said, it's called "illegal" because it's doing something against "the rules".

 

[aimeeandbeatles]

And because the programmers weren't expecting n00bs to think they broke the law.

How about this?

...what else can make a program stop working, a herd of camels running down my computer?

 

[Till]

And because the programmers weren't expecting n00bs to think they broke the law.

How about this?

...what else can make a program stop working, a herd of camels running down my computer?

That's not a useful error message for trouble shooting. Your geek assignment for the day:
Find out where crash logs are kept in Vista (It's Doc&Settings\All Users\Microsoft\Dr.Watson in XP.). Then try to find the error number for the crash in the log.

 

[aimeeandbeatles]

That's not a useful error message for trouble shooting. Your geek assignment for the day:
Find out where crash logs are kept in Vista (It's Doc&Settings\All Users\Microsoft\Dr.Watson under XP.). Then try to find the error number for the crash in the log.

Actually, I know exactly why it crashed. It was TTD and I forgot to copy a DLL file into the directory.

 

[Flying Pig]

From a little book called 'My Computer Hates Me';

Your machine has just flown to Cuba and whipped out someone's kidney

I think it's like the term illegal move - it tried to do something it was not allowed to do, hence illegal.

 

[Genocidicbunny]

A computer has a set of rules in which it operates -- your program's algorithm. Outside of those rules, it has no way to make sense of data. So going against those rules is illegal for the computer.

 

[ParadigmShifter]

Well the operating system imposes rules for user mode programs too.

 

[Souron]

A computer has a set of rules in which it operates -- your program's algorithm. Outside of those rules, it has no way to make sense of data. So going against those rules is illegal for the computer.

No, that's called "undefined behavior". It's when your programs do not obey some kind of contract that is implied by the hardware, some library, or the programming language.

An illegal operation is an operation that is explicitly prohibited by the operating system, such as accessing protected memory.

The two are related, because undefined behavior can cause an illegal operation.

 

[Cutlass]

It's illegal because even back when they coined the term MS was planning world domination.

 

[Serutan]

Illegal operation can also because an undefined (i.e. illegal) instruction was loaded into the CPU.
Usually caused by stack corruption.

 

[Genocidicbunny]

No, that's called "undefined behavior". It's when your programs do not obey some kind of contract that is implied by the hardware, some library, or the programming language.

An illegal operation is an operation that is explicitly prohibited by the operating system, such as accessing protected memory.

The two are related, because undefined behavior can cause an illegal operation.

Thats sorta what I meant. It was a hot day and I was in the sun for too long

 

[Macha]

Actually, I know exactly why it crashed. It was TTD and I forgot to copy a DLL file into the directory.

Get openTTD (http://openttd.org ). It's much better. You still need some files of the orignal TTD first however.

Illegal operation means a program is trying to do something it shouldn't. Usually means
(a) the program has a bug
or
(b) You need more memory.