Plug-in type program storage

Program storage apparatus for use with an electrical data processing device having a plurality of active switching elements of a selected electrical type, each active switching element having an input and an output, said apparatus comprising:

• a plurality of continuously electrically reprogrammable active unitary storage elements of the same electrical type as said active switching elements, each unitary storage element having an input circuit adapted to receive a plurality of input states of a control signal from said output of an associated active switching element, each unitary storage element having an output circuit separate from said input circuit and adapted to settably assume one of a plurality of output states responsive to an associated one of said each element input states, each said unitary storage element output circuit controlling a quantity of electrical energy greater than another quantity of electrical energy supplied to said input circuits;
• and
• means for substantially simultaneously directly electrically connecting each of said unitary storage element input and output circuits to a corresponding one of the inputs and outputs of said switching elements when said program storage apparatus is installed at said electrical data processing device and for substantially simultaneously disconnecting all of said unitary storage element input and output circuits from said switching elements when said program storage apparatus is removed from said electrical data processing device.