801 Storage: Architecture and Programming

Based on novel architecture, the 801 minicomputer project has developed a low-level storage manager that can significantly simplify storage programming in subsystems and applications. The storage manager embodies three ideas: (1) large virtual storage, to contain all temporary data and permanent files for the active programs; (2) the innovation of database storage, which has implicit properties of access serializability and atomic update, similar to those of database transaction systems; and (3) access to all storage, including files, by the usual operations and types of a high-level programming language. The IBM RT PC implements the hardware architecture necessary for these storage facilities in its storage controller (MMU). The storage manager and language elements required, as well as subsystems and applications that use them, have been implemented and studied in a prototype operating system called CPR, that runs on the RT PC. Low cost and good performance are achieved in both hardware and software. The design is intended to be extensible across a wide performance/cost spectrum. © 1988, ACM. All rights reserved.