I have already posted this in another thread (on non-BTL C compilers), but it's more relevant here. My 1985 review of Coherent for BYTE Magazine:

https://www.mrochkind.com/mrochkind/docs/Byte-Pick-Coherent-Theos.pdf

I see that I went into some detail. For example:

"Of the 77 requests in the Version 7 nroff. only 31 are present in Coherent (the most useful 31. however)."

And this, although I'm sure there were incompatibilities I didn't uncover:

"Coherent has all the Version 7 system calls except nice (which sets a process's priority). and they seem to be used in the same way. It should be easy to port C programs between Coherent and UNIX Version 7."

On the whole my review was very positive.

Marc

On Fri, Mar 15, 2024 at 7:43 AM Dan Cross <crossd@gmail.com> wrote:

On Fri, Mar 15, 2024 at 9:03 AM Dan Cross <crossd@gmail.com> wrote:
>
> On Fri, Mar 15, 2024 at 3:00 AM Rob Pike <robpike@gmail.com> wrote:
> > Another detail. There was lawyerly concern about the code being stolen, and we (127) were asked to find ways to test, absent their source, whether they had just stolen our source and built the binaries. It was soon concluded that there were enough details different to definitively say that at least most of the work was done in a clean room, as advertised, but the piece I liked best is that their PPT(1) program (ASCII art showing a paper tape rendering the argument text) did not include the original, and just discovered, bug that mispunched, if I remember right, the letter 'R'.
>
> Along those lines, Dennis Ritchie wrote up a summary of the event on
> USENET; apparently in 1998 (I had no idea it was this late):
> https://groups.google.com/g/alt.folklore.computers/c/_ZaYeY46eb4/m/5B41Uym6d4QJ

Sorry, just to clarify: I meant I had no idea Dennis's posting about
the event happened so late; by 1998 USENET was basically overrun by
spam. Obviously, the inspection trip had happened much earlier.

- Dan C.