TALL: A list processor for the Philco 2000 computer
Several of the computer languages that are oriented toward problems in symbol manipulation use a list type of memory organization.1 The advantages of such a memory organization have been discussed elsewhere and will not be repeated here. The purpose of this note is to describe the method used in realizing a list language on the Philco 2000.
Information Processing Language V (IPL-V) was chosen as the source language for the list processor for the 2000 because this language has been well documented and has been implemented on several computers.2 Heretofore, IPL-V has been implemented as an interpretive system. The interpretive system has three major components: (1) a loader which translates card images into internal machine words; (2) an interpreter which decodes instructions; and (3) a set of primitive processes, the “J's,” which make up the bulk of the instruction vocabulary. The implementation of such an interpretive system has been a rather lengthy procedure usually estimated as taking six man-months.