The PDP-14 was a specialized computer from Digital Equipment Corporation’s Industrial Products Group designed to replace industrial level relay controls for machinery and machine tools that performed repetitive tasks.
The PDP-14 was specifically designed to be the first level of factory automation, functioning as a programmable logic controller (PLC), through its ability to communicate with a standard DEC PDP-8 minicomputer.
[4] The PDP-14 was designed to process Boolean equations, usually expressed as “ladder diagrams” and as such had a programmable read-only program (PROM) memory.
Later versions (for example, the PDP-14/30, whose instruction set was not binary compatible)[5] are based on PDP-8 physical packaging technology.
The system's configuration included a control unit and a number of external boxes:[5] Hence the combined usable output address space of the O-boxes, A-boxes and S-boxes was 255 or fewer.