System Design of a FORTRAN Machine

Abstract

A system design is given for a computer capable of direct execution of FORTRAN language source statements. The allowed types of statements are the FORTRAN DO, GO TO, computed GO TO, Arithmetic, READ, PRINT, arithmetic IF, CONTINUE, PAUSE, DIMENSION and END statements. Up to two subscripts are allowed for variables and no FORMAT statement is needed. The programmer's source program is converted to a slightly modified form while being loaded and placed in a Program Area in lower memory. His original variable names and statement numbers are retained in a Symbol Table in upper memory, which also serves as the data storage area. During execution of the program each FORTRAN statement is read and interpreted at basic circuit speeds since the machine is a hardware interpreter for these statements. The machine corresponds therefore to a ``one-pass, load-and-go'' compiler except, of course, that there is no translation to a different machine language. It is estimated that the control circuitry for this machine will require on the order of 10,000 diodes and 100 flip-flops. This does not include arithmetic circuitry.