A microprocessor incorporates most or all of the functions of a central processing unit (CPU) on a single integrated circuit (IC). The first microprocessors emerged in the early 1970s and were used for electronic calculators using Binary Coded decimal(BCD) arithmetic on 4-bit words. Other embedded uses of 4-and 8-bit microprocessors, such as terminals and printers, various kinds of automation etc, followed rather quickly. Affordable 8-bit microprocessors with 16-bit addressing also led to the first general purpose micro computers in the mid-1970s.