The MC14500B Industrial Control Unit (ICU) is a CMOS one-bit microprocessor designed by Motorola for simple control applications in 1977.
1-bit microprocessor MC14500BCP
In computer architecture, 1-bit integers or other data units are those that are 1 bit wide. Also, 1-bit central processing unit (CPU) and arithmetic logic unit (ALU) architectures are those that are based on registers of that size.
1-bit programmable logic controller MC14500BCP