Re: First client: SCO
"Carrying screeds of comments (i.e. human readable text within the object code) forward would only have happened if exact *copying* had taken place, and nobody ever alleged that, as far as I know."
Jerry Pournelle certainly did:
"Legend tells us Kildall himself buried a secret message in CP/M and that the message can also be found in MS-DOS.
In 2006, science fiction writer and technology reporter Jerry Pournelle said on “This Week in Tech,” an Internet radio show, that this secret command triggered the display of a copyright notice for DRI and Kildall’s full name. According to Pournelle, Kildall had demonstrated this command to him by typing it into DOS; it produced the notice and thus proved that DOS was copied from CP/M.
This story, circulated for years, has a few problems. First, no one knows the secret command; Pournelle claims he wrote the command down but has never shown it to anyone. In addition, such a message would be easily seen by opening the binary files in a simple text editor unless the message was encrypted. CP/M had to fit on a floppy disk that held only 160 kilobytes; Kildall’s achievement was squeezing an entire operating system into such a small footprint. But it is difficult to imagine he could do this and also squeeze in an undetectable encryption routine. And although we’re now in an era of hackers breaking into heavily secured computers, no one has ever cracked DOS to find this secret command.
But I set out to look for it anyway. I used a utility program developed at SAFE to extract strings of text from binary files. Not only did Kildall’s name not show up in any QDOS or MS-DOS text strings, it did not show up in CP/M either. The term “Digital Research” did appear in copyright notices in the CP/M binary files, but not in MS-DOS or QDOS binary files.
If Jerry Pournelle did indeed see a hidden message revealed by a secret command, it was not in MS-DOS"