There’s a lovely story[1] from the early days of personal computing:

“GO.COM contained no program bytes at all – it was entirely empty. However, because GO.COM was empty, but still a valid program file as far as CP/M was concerned (it had a directory entry and file-name ending with .com), the CP/M loader, the part of the OS whose job it is to pull programs off disk and slap them into the TPA, would still load it!

So, how does this help? Well, using the scenario above:

• the user exited WordStar • the user ran DIR (or whatever else they needed) and at some future point would be ready to re-run Wordstar • the user now ‘loaded’ and ran GO.COM • the loader would load zero bytes of the GO.COM program off disk into the TPA – starting at address 0100h – and then jump to 0100h – to run the program it just loaded [GO.COM]! • result – it simply re-ran whatever was in the TPA when the user last exited to DOS – instantly [WordStar in this example]!

So, GO.COM, which consisted of zero bytes of code – and sold for £5 a copy is, I figure, the most profitable program ever written (as any other program will return mathematically fewer £s per byte than GO.COM did)!”

1. http://web.archive.org/web/20160304014157/http://peetm.com/b...

Thanks! I remember reading about this a while back, but lost the link.

Empty files remind me of an episode where I worked. We were supposed to provide a set of files for a court case. But there was a missing zero byte file due to a glitch in processing. So just create one, right? NOPE. The client insisted we find and copy the original empty file from the original media.

You just know it's because, if you just made a new zero-byte file, the opposition in the case would claim that you forged the file and that the evidence was then tainted. Stupid, but your goal here isn't to reproduce the file, it's to stop a stupid argument from convincing stupid people to make a stupid decision.

> your goal...[is] to stop a stupid argument from convincing stupid people to make a stupid decision.

This is the best explanation of legal practice I have ever seen.

But... to be sent, the file is recreated a bunch of times right? Because a computer only ever copies, and never “moves”, right? How can it then possibly matter whether the 0b file was recreated by a computer from the instruction of copying the file (which then just turns into an instruction to create the file), or if it was created directly through instructing the computer to create the file?

Gah, something something colored bits. http://ansuz.sooke.bc.ca/entry/23

Computers do "move" files, in some cases, by updating the entry in the filesystem registry. In such a case, it might be that no change was made to the file on disk, so no copy was made at all.

I interpreted "provide a set of files for a court case" as some form of sending it either through the Internet or to some portable storage media. He also said "The client insisted we find and copy the original empty file from the original media", which also indicates that. I therefore intended "move" to mean "move from one storage media/computer to another". You're of course correct that if you "move" a file on one file system, the bits won't actually be copied (or moved) anywhere.

Sure, no argument. I was responding only to the "computer only ever copies" statement. Sometimes it's hard to know how literal someone is being. :)

It's like homeopathic copying: A zero byte string can contain trace amounts of the original.

You wanted to provide a zero-byte file of the wrong colour. Unlike in physical reality, in legal world it strongly matters what colors are your bits (or in this case, what color is the lack of them).

http://ansuz.sooke.bc.ca/entry/23

Not a wholly insane request if they were interested in the file metadata as much as the file data.

You might think, but metadata travels separately from the actual file, so that wasn't a factor.

Depending on how it's copied, they can be preserved.

Well, I can see the point of leaving a trail that shows you aren't fraudulently claiming the file is zero bytes. Otherwise, it's just your word.

Yeah, if they didn't find a copy on the backup/original media to confirm it's zero bytes, then really all they've provided is their assumption that it's zero bytes.

I'm no lawyer, but the testimony of the IT guy (and associated reasoning/etc) seems like a totally different kind of evidence than a true and accurate copy of a file from an original medium. And having the IT guy testifying seems like way more of a pain than just making him find the file.

"prior art" is a term concerning patents, whereas this is copyright.

There needs to be a certain level of creative work to qualify for copyright, and an empty program that does nothing is rather unlikely to qualify.

The definite case on that subject must be John Cage's "4:33", which is 4 minutes and 33 seconds of silence. Its copyright has been upheld in court. Yes, the estate of John Cage sued somebody who "quoted" to much of his work of silence.

That sounds somewhat silly, yet it's well-reasoned: the infringing artist actually acknowledged Cage in the CD inset. And 4'33 isn't really only silence. Audio recordings feature the pianist sitting down, open and closing the piano cover, and the audience making various noises. It's somewhat "out there" obviously, but just the fact that it's rather well-known kind of shows that it did what it was supposed to do.