The 1-bit architecture is a microprocessor or computer architecture that has a datapath width or a highest operand width of 1 bit. These architectures typically have a matching register file with registers width of 1 bit. Very few 1-bit architecture CPUs were commercially marketed.

Applications

Some of the earliest calculators had bit-serial architecture, most quickly switched over to 4-bit and then 16-bit microprocessors. Today all 1-bit microprocessors are largely obsolete, even academia.

1-bit microprocessors

• Motorola MC14500
• General Instrument SBA
• General Instrument SBA-1

1-bit systems

• Motorola WDR-1-Bit Computer