The PDP-3 is designed to accommodate a variety of input-output
equipment. Of particular interest is the ease with which new, and
perhaps unusual, external equipment can be added to the machine.
Optional in-out devices include Cathode Ray Tube Display, Magnetic Tape,
Real Time Clock, Line Printer and Analog to Digital Converters. The
method of operation of PDP-3 with these optional devices is similar to
the standard input-output equipment.