BATCH-11/DOS-11, also known simply as DOS-11, was an operating system by Digital Equipment Corporation (DEC) of Maynard, Massachusetts. The first version of DOS-11 (V08-02) was released in 1970 and was the first operating system to run on the Digital PDP-11 minicomputer.DOS-11 was not known to be easy to use even in its day and became much less used in 1973 with the release of the RT-11 operating system. It came with XXDP, a diagnostics and monitor program for the PDP-11.