Page "Accumulator (computing)" Paragraph 3

An accumulator machine, also called a 1-operand machine, or a CPU with accumulator-based architecture, is a kind of CPU where, although it may have several registers, the CPU mostly stores the results of calculations in one special register, typically called " the accumulator ".

Historically almost all early computers were accumulator machines ; and many microcontrollers still popular as of 2010 ( such as the 68HC12, the PICmicro, the 8051 and several others ) are basically accumulator machines.