Source : Free On-Line Dictionary of Computing

PDP-6
     
         Programmed Data Processor model 6.  A computer
        designed around 1960 with more or less exactly the same
        hardware architecture as the {PDP-10}.  It already had
        multi-user {time sharing} and {batch processing} and
        multi-level priority {interrupts}
     
        (1996-12-21)