This short paper describes the outline of a servo system for manipulators, recently developed at the Electrotechnical Laboratory. The servo system is implemented on a high speed micro-computer and capable of performing dynamics calculation and coordinate transformation of the manipulator in a cycle time for the servo (2.5 mili sec.) . Computation algorithms are formalized in vector form, and directly coded into programs, using vector macro language. The programs are expanded into assembly mnemonic form by macro processor. The mnemonic programs are converted into machine code by a cross assembler which runs on a host computer (VAX 11/780) . Then the machine code prograhi is downline loaded onto the realtime micro-computer (MIPROC-16) . In this servo system, controlled variables are arbitrarily chosen, and mode of control for each variable is also arbitrary. We can select the most suitable coordinate frame in order to do a task. For each motion component with respect to the coordinate frame, position, velocity, acceleration, force or compliance can be controlled. Using the servo system, sophisticated tasks such as parts mating or tool handling will be easily performed.