Development and attributes of z/Architecture
K. E. Plambeck, Wojciech Eckert, Rob Rogers, Charles F. Webb · IBM Journal of Research and Development · 2002
The IBM z/Architecture™ instruction set architecture (ISA) is an extension of the IBM Enterprise Systems Architecture/390® (ESA/390) ISA and features 64-bit general registers, 64-bit operations, and 64-bit virtual and real addressing. In addition, z/Architecture includes new instructions to optimize the handling of modern multi-byte character encodings and to improve the performance of programs written in high-level languages. It provides compatibility for ESA/390 application programs and increases the ease of development of new application programs. This paper presents an overview of the interesting aspects of z/Architecture and some of the associated decisions and tradeoffs made in its development.