Peet Morris wrote a post about GO.COM, a zero-byte program on CP/M that was a valid program file.
HN links it as a favorite programming story about the empty program, often cited with the line that the best code is no code.
Reminds me of GO.COM (http://peetm.com/blog/?p=55) That is/was an example.
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"
It also wasn't unusual to try and recover data from memory after a program crashed by launching a small program that dumped memory to disk. 100% reliable? No, but it was the best one sometimes had.
Great Read! I have been mulling over the idea of creating a curated list of interesting Programming Stories. Here are some of those which I can remember from top of my head:
* 500 Mile Email [http://www.ibiblio.org/harris/500milemail.html]
* Infinitely Profitable Program [http://peetm.com/blog/?p=55]
* The PGPi Scanning Project [http://www.pgpi.org/pgpi/project/scanning/]
* DirectX vs OpenGL [http://programmers.stackexchange.com/a/88055/75581]
Think anyone can contribute?
In the sense that perfection is achieved when there is nothing left to take away, GO.COM as described in http://peetm.com/blog/?p=55. It doubles as a winning entry in 1994's IOCCC.
An empty file was also the infinitely profitable program: http://peetm.com/blog/?p=55 On CP/M, it was useful to rerun the previous program that was still in memory.
This reminds me of the story about the "go.com" program someone sold for £5, which was just an empty file: http://peetm.com/blog/?p=55
The best code is no code!
Related, one of my favorite programming stories: the 0-byte program http://peetm.com/blog/?p=55