IBM scientists at the Thomas J. Watson Research Center built the Research Parallel Processing Prototype (RP3) at IBM's Hawthorne, N.Y., facility in the late-1980s to support and compare a variety of parallel computational models. As an MIMD (multiple-instruction stream, multiple-data stream) system designed to accommodate 512 32-bit state-of-the-art microprocessors with a reduced instruction set (RISC) architecture, the RP3 was targeted to perform in the range of a billion instructions every second. A uniquely flexible main memory architecture allowed real-time dynamic partitioning between efficiently accessed global and local memory in the RP3. This view shows a 64-way segment of the RP3 with a performance in the range of 128 MIPS. (VV1005)