Motorola MC14500B
The Motorola MC14500B Industrial Control Unit (ICU) is a CMOS one-bit microprocessor designed for simple control applications. It is well-suited to the implementation of ladder logic, and thus could be used to replace relay systems and programmable logic controllers. The MC14500B unit does not include a program counter, therefore the size of supported memory is dependent on the implementation of program counter.
The ICU architecture is similar to that of the DEC PDP-14 computer.