Preface

During the four years since the RISC System/6000® (RS/6000) announcement in February of 1990, IBM® has strengthened its product line with microprocessor enhancements, increased memory capacity, improved graphics, greatly expanded I/O adapters, and new AIX® and compiler releases. In 1991, IBM began planning for future RS/6000 systems that would span the range from small, battery-operated products to very large supercomputers and mainframes. As the first step toward achieving this “palmtop to teraFLOPS” goal with a single architecture, IBM investigated further optimizations for the original POWER Architecture™. This effort led to the creation of the PowerPC™ alliance (IBM Corporation, Motorola™, Inc., and Apple® Computer Corporation) and the definition of the PowerPC Architecture™. Today, the single-chip PowerPC 601™ processor is the basis of IBM's entry systems. A more aggressively superscalar version of the original POWER processor, the multichip POWER2™ processor, is exploited in our current IBM high-end RISC systems. As technology continues to advance, PowerPC implementations will provide the basis for high-performance 64-bit super servers.