Closing the software gap for interactive mini/microcomputation: Direct execution of microprogrammed block-diagram primitives

Block-diagram programs, for instrumentation, control, and simulation systems are especially easy to translate, since no explicit precedence analysis is needed. Block-diagram primitives range from simple adders to complete real-time controllers. They are pure-procedure, reentrant microprograms or threaded code in read-only memory, which may be pre-programmed and plugged in for special applications. In addition to hand "assembly" and optimizing compilation of block-diagram programs, we exhibit the new direct-executing MICRODARE II system, which embeds block-diagram "assembly" in an advanced BASIC dialect serving for interactive editing, job control, and file manipulation. Execution speeds of the new systems permit LSI-11 microcomputers and PDP-11 minis to match and exceed those of a CDC 6400; a number of examples are shown. The report continues with a discussion of future multi-task, multiprocessor real-time BASIC systems incorporating MICRODARE. We finally describe a new two-processor system consisting of an LSI-11 running MICRODARE software joined by a two-port memory to an ultra-fast bit-sliced 2903/2910 processor executing block-diagram microprograms.