Albert Chang

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.

Power System Dynamic Equivalents

This paper describes a method for determining a simplified equivalent mathematical representation of portions of a power system for transient stability analysis. The method leads to equations that do not correspond directly to a system composed of normal power system components. Conditions under which it is possible to obtain such an equivalent are given, and the results of applying the method to the 118-bus IEEE test system are reported.

Evolution of storage facilities in AIX Version 3 for RISC System/6000 processors

This paper discusses how the AIX Version 3 storage facilities include features not found in other implementations of the UNIX operating system. Maximum virtual memory is more than 1000 terabytes and is used pervasively to access all files and the meta-data of the file systems. Each separate file system (subtree) of the file name hierarchy occupies a logical disk volume, composed of space from possibly several disks. Database memory (a variant of virtual memory) and other database techniques are used to manage file system meta-data. These features provide the capacity to address large applications and many users, simplified program access to file data, efficient file buffering in memory, flexible management of disk space, and reliable file systems with short restart times.