[WalterBright]

The differences such as A: vs SY0:, are differences only in detail. The unix command line is fundamentally different, not just different in detail. BTW, RT-11 used PIP.

> The page you link to just says "Sign in to Twitter". For the sake of courtesy, I'd rather not go into how I feel about that invitation.

It goes to my profile page. Of course, I am logged in to twitter. I had no idea that it was necessary to sign in to twitter to see my profile page. There was no nefarious intent. I am not aware of any benefit that may accrue to me from you signing up for a twitter account.

[kragen]

I agree that Unix was fundamentally different in many ways, but CP/M wasn't a copy of Unix either; if anything, RT-11 was slightly more Unix-like than CP/M was. Because CP/M was evidently worse than RT-11 in many apparently unnecessary ways, I suspect that it was drawing from some other source.

I didn't suspect any nefarious intent, but if I didn't tell you it had happened, you would never have known. My apologies if it sounded like I was blaming you for it.

[WalterBright]

I don't see any heritage of unix in CP/M, but I do see a heritage from DEC. Not an exact copy, of course.

> if I didn't tell you it had happened, you would never have known

That's right, and now I know. Thanks!

> My apologies if it sounded like I was blaming you for it.

Thank you. Apology accepted!

[kragen]

Do you have any clues about which DEC system it might be drawing these other elements from? I mean specifically:

- FCBs.

- A command interpreter prompt ending in ">" rather than "*" or ".".

- 8-character filenames (rather than 6).

- ASCII filenames (rather than RADIX-50).

- Drive letters.

- PIP switches in square brackets rather than introduced by slashes. (Some TENEX programs evidently enclosed their switches in parentheses, but the ones I've seen so far don't use square brackets.)

- Launching programs from the command interpreter with command-line arguments, like Unix.

Maybe Kildall thought all these things up himself, but I suspect some previous DEC OS was their origin. But it isn't RT-11, TENEX, the DEC 10/50 monitor, TOPS-20, or VMS.

I want to emphasize I'm not claiming that these are advances or innovations. I'm just saying that they suggest some other influence.