An intermediate systems language for the PDP-11
Peter Karasz · ACM SIGPLAN Notices · 1977
In this paper we describe Version 2 of Intermediate Systems Language (ISL/V2), a general purpose software implementation language developed at the B. F. Goodrich Company. The particular implementation we discuss here is for the PDP-11 family of minicomputers that use the 11/40 instruction set.ISL has a FORTRAN like syntax with a number of added features to make it a versatile software development tool. It is the implementation language of IDMS-11, a CODASYL-type Data Base Management System (DBMS) for the PDP-11.The language puts a minimal amount of constraint on the programmer. Top down logic design and modular programming are encouraged but not enforced by the compiler. The ISL compiler produces an assembly program that very closely approaches hand-written code both in appearance and quality. A compile time option is provided for the generation of re-entrant programs. In-line assembler language statements may be inserted into the ISL source program.