The original LISP machine, the IBM 704, had CAR and CDR as primitives. And boy, were they primitive: > These names are hold-overs from the original implementat

The original LISP machine, the IBM 704, had CAR and CDR as primitives. And boy, were they primitive: > These names are hold-overs from the original implementation of LISP on the IBM 704. That machine had partial-word instructions to reference the address and decrement parts of a machine location. The a of CAR comes from "address", the d of CDR comes from "decrement". the c and r come from "contents of" and "register". Thus CAR could be read "contents of address part of register". http://www.iwriteiam.nl/HaCAR_CDR.html http://www.iwriteiam.nl/HaCAR_CDR.html