PDP-10 (Programmed Data Processor - 10) was a series of large, 36-bit computers made by Digital Equipment Corporation from the 1960s to the 1980s. Used in many universities and research laboratories, they played an important role in the popularization of time-sharing in the 1970s (the prominent model of computing having been the batch processing). The most well-known operating systems used on PDP-10 were TOPS-10, TOPS-20, TENEX, and ITS.