(RISC System/6000) The earlier generation and original name of IBM's System p family of scientific workstations and servers that merged into the Power Systems brand. The RS/6000 line was the first to use IBM's RISC-based POWER chip architecture, and both POWER and PowerPC CPUs have been used in various models. AIX (Unix) was the RS/6000's primary operating system. The RS/6000 originally supported the Micro Channel bus, but later switched to PCI. See Power Systems and POWER.