Series X. Programming Instructions -- (1951) 1956-1988 (1990), comprising nine boxes (9 cu. ft.), mainly consists of programs and computer printouts for Newell's RAND and Carnegie Mellon projects, including the NSS chess machine, LT, IPLs, GPS, and JOSS. Also represented are the RAND efforts regarding the OPS production system languages, and ARPA programming efforts for L* and ZOG research. Other Newell research programming includes printouts and programming for CIT's first PDP-10 computers, advancements on the LISP list-processing language for AI programming, and the MERLIN program -- a serious effort to construct a system that would understand and explain artificial intelligence.