Source : Free On-Line Dictionary of Computing

Motorola 14500B
     
         (MC14500B) A 1-bit {ICU} from {Motorola}.
        Probably the limit in small processors, the 14500B had a 4-bit
        instruction and controlled a single data read/write line, used
        for application control.  It had no address bus - that was an
        external unit that was added on.  Another {CPU} could be used
        to feed control instructions to the 14500B in an application.
        It had only 16 pins, less than a typical {RAM} chip, and ran
        at 1 {MHz}.
     
        (1994-11-30)