Sep 06, 2017

> Why wasn't it ported, or a fresh one built?... In fact, there were Lisp compilers for the PDP-10, which (I presume) could run on the PDP-11

The PDP-11 was in no way compatible with the PDP-10, and there was no way a PDP-10 Lisp implementation like Maclisp or Interlisp would fit on a PDP-11. All you have to do is Google "PDP-11 Lisp" to see that there were many different Lisp interpreters and at least one compiler implemented for the PDP-11 throughout the 1970s. Likewise Intel processors - the first implementation of Lisp on the 8080 was done by Takashi Chikayama ( in 1976 (