Interface Specifications for SCR (Software Cost Reduction) (A-7E) Extended Computer Module. Revised.

摘要

This document describes the programmer interface to a computing machine partially implemented in software. The Extended Computer is part of NRL's Software Cost Reduction (SCR) project, to demonstrate the feasibility of applying advanced software engineering techniques to complex real-time systems in order to simplify maintenance. The Extended Computer allows code portability among avionics computers by providing extensible addressing, uniform i/o and data access, representation-independent data types, uniform event signalling, a standard subprogram invocation mechanism, and parallel process capability. The purpose of the Extended Computer is to allow the remainder of the software to remain unchanged when the host computer is changed or replaced. This report describes the modular structure of the Extended Computer, and contains the abstract interface specifications for all the facilities provided to users. It serves as development and maintenance documentation for the SCR software design, and is also intended as a model for other people interested in applying the abstract interface approach on other software projects. (Author)