Evolution of the PowerPC architecture
K. Diefendorff, Richard Oehler, R. Hochsprung · IEEE Micro · 1994
The PowerPC is a new RISC architecture derived from IBM's POWER architecture. The changes made to POWER simplify implementations, increase clock rates, enable a higher degree of superscalar execution, extend the architecture to 64 bits, and add multiprocessor support. For compatibility with existing software, the developers retained POWER's basic instruction set, opcode assignments, and programming model.>