You can find the source code here: http://www.softwarepreservation.org/projects/LISP/lisp15_family/#LISP_I_and_LISP_1.5_for_IBM_704,_709,_7090_ http://www.softw

You can find the source code here: http://www.softwarepreservation.org/projects/LISP/lisp15_family/#LISP_I_and_LISP_1.5_for_IBM_704,_709,_7090_ http://www.softwarepreservation.org/projects/LISP/lisp15_fam... The same site has the sources for plenty of other versions.