Summary-The COordinate Rotation DIgital Computer(CORDIC) is special-purpose digital computer for real-time airborne computa tion. In this computer, a unique computing technique is employed which is especially suitable for solving the trigonometric relation- ships involved in plane coordinate rotation and conversion from rectangular to polar coordinates. CORDIC is an entire-transfer com- puter; it contains a special serial arithmetic unit consisting of three shift registers, three adder-subtractors, and special interconnections. By use of a prescribed sequence of conditional additions or sub- tractions, the CORDIC arithmetic unit can be controlled to solve either set of the following equations: