Had the concept of an “operating system” crystallized enough in 1970 that someone would know what was meant by a “new one”? Or did they basically invent the concept?
UNIX is a play on MULTICS, an earlier time-sharing operating system.
The 1965 MULTICS paper at https://www.multicians.org/fjcc1.html has "it is an obligation to present and future system designers to make the inner operating system as lucid as possible so as to reveal the basic system issues" and cites ""IBM Operating System/360, PL/I: Language Specifications," File No. S360-29, Form C28-6571-1, I.B.M. Corp."
