Guy, is that a trick bet? The CDC 6500 had a lisp (UTEXAS?) with CAR, CDR, and CZR slots for the three 18-bit addresses in their 60-bit words. However, if I remember correctly, you would technically win your bet, since there still wasn't a three-slot cons. You had to do something like: (SETQ CELL (CONS A B)) (RPLACZ CELL C) jlm