I thought c was primarily developed for the initial purpose of being the language used to write Unix and that their developments were practically one after the other and that Ritchie and Thompson were colleagues at Bell? C was designed for portability in mind?
I could be wrong, but I think Unix was originally written in assembler, which isn't portable.
Unix first appeared on a PDP-7 (not PDP-11). PDP-7 was pretty old even by the standards of the time.
"Originally, UNIX was written in PDP-7 assembly, and then in PDP-11 assembly, but then when UNIX V4 began to be re-written in C in 1973 and was run mostly on the PDP-11.
So far as I can tell, there is no Ancient C compiler that targets the PDP-7, nor any provision for running UNIX V4 or later on the PDP-7" [0] The link also contains some other interesting commentary.
I seem to recall that Thompson wanted to write code in Fortran.
I'm probably getting a few details wrong. The systems were extraordinarily constrained, something like 4K of RAM. "++" exists because it was more concise that "+= 1" (although K&R C uses "=+ 1", I think). They really wanted to make every byte count.
Thanks for painting a mire elaborate picture of how it all went. Of course c had to be compiled on some system, and there were probably a good variety of systems around back then.