A two-level microprogrammed multiprocessor system, MUNAP, along with its support software has been developed as a research vehicle for solving nonnumeric and associated problems. The MUNAP system provides highly parallel and distributed functions for nonnumeric processing, such as variable length word addressing, data permutation at the microprogram level, and bit operation and field handling at the multinanoprogram level. To control these functions efficiently, a 28-bit microinstruction simultaneously drives several nanoprogram streams of 40-bit nanoinstructions in the four 16-bit processor units. This scheme not only provides the ability to organize a number of modular processing elements into a single, parallel processable computer system, but also allows MUNAP to change its architecture at the firmware level.