Here is an undated listing of an early compiler https://raw.githubusercontent.com/PDP-6/ITS-138/master/listings/LISP_C52.pdf
I typed it in, made a Maclisp emulator in Common Lisp, and verified that
the LISP C52 compiler works. It outputs LAP code for the PDP-6.
CL-USER> (maclisp-load "LISP C52")
CL-USER> (maclisp::defprop testing
(maclisp::lambda (x) (maclisp::plus x 1))
maclisp::expr)
CL-USER> (maclisp::compile testing)
(LAP TESTING SUBR)
(MOVEI 2 (QUOTE 1))
(PUSH P 1)
(PUSH P 1)
(CALL 2 (E *PLUS))
(PUSH P 1)
(SUB P (C 0 0 3 3))
(POPJ P)
NIL
^L
(TESTING)
CL-USER>
--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)