I believe CP/M was inspired by many of the DEC traditions,
If you do some Internet searching, there is an interview (IIRC from Byte Magazine in the late 1970s) where its author (Gary Kildall) straight out said he was trying to emulate RT-11 for an 8080. The funny thing to remember is that Kildall was a language guy, he wrote CP/M to demo his programming language PL/M for Intel. The demo ended up having more longevity than the tool he was trying to sell.