RISC Technology Personal Computer.(Commonly, but incorrectly, known as the "PC-RT", later changed to just "RT") IBM' s first RISC-based Unix computer.The RT-PC was the predecessor to IBM' s RS/6000. It ran AIX 1.x and 2.x and had a PC-AT bus and IBM' s ROMPmicroprocessor.It was withdrawn from the marketing around 1989 or 1990.(1995-04-06)