This thesis examines computer architecture and operating system developments to determine a set of requirements applicable to all computer systems. The requirements obtained by this examination are used to define the concept of a nucleus for a computer system. A nucleus structure, based around an addressing scheme and a set of functions, is presented. This structure does not include processor and peripheral designs, but concentrates on the interaction between these components. The proposed addressing scheme is based on capability addressing, with the structure recognizing processors, peripherals, processes and files as addressable units. The functions proposed assist in scheduling of processes for processors and peripherals. These functions are also referenced through the addressing scheme which assists in the creation of virtual machine environments. Implementation techniques for the proposed nucleus are also examined in the context of validating the nucleus proposal. These implementation techniques are also discussed as final implementation methods.