C.ai--A LISP Processor for C.ai,

A special microprogram controlled process designed for efficient interpretation of the LISP language is described. The processor has a fairly large, fast scratch-pad memory and uses two cache memories for the LISP program and data being interpreted and for the LISP interpreter. Several special purpose registers, small function units, and general byte manipulation capabilities are present. The approach taken has been to avoid unorthodox implementation schemes and employs little in the way of unusually new and untried hardware. Such a conservative approach should enable and implementation in a reasonable length of time. The microprogrammed processes include a storage-compacting garbage-collector, which can be made to operate incrementally in parallel with user-program execution. This option avoids interruptions in LISP execution for garbage collection. Author