The authors propose a hybrid microprocessing/microprogramming (HMM) scheme to implement the algorithmic state machines (ASMs). First, a behavior model of the HMM is defined. This model carries out any task by partitioning it into a microprocessing subtask which is executed by a microprocessor unit and a microprogramming subtask which is executed by a microprogrammed unit. The problems of constructing the microprogrammed unit of HMM are then considered, including the synthesis of the control store sequencer, compaction of the control store, and microcode generation. Finally, an application example utilizing the above method to design a universal floppy disk controller which can accept all kinds of encoding formats is provided.