Partitioned multiprocessor programming system

A control method for a multiprocessor (MP) system having plural CPUs sharing a main storage (MS) and I/O processing means for connecting a plurality of I/O devices to MS, the control method enabling the MP to execute a uniprocessor programming system (UPS) simultaneously on plural CPUs in the MP, even though the UPS is designed to only execute on a uniprocessor (UP) system having the same or a different architecture than the MP, the MP control method comprising:

• having plural copies of the UPS in the MS, each copy of the UPS containing an identical set of UPS addresses within a range from UPS address zero to a maximum UPS address determined by the number n of bit positions in each address programmed into the UPS, and n being the order of the highest-order bit position in any explicit UPS address,
• locating a different UPS copy boundary for the UPS address zero of each of the plural copies of the UPS, the UPS copy boundaries being different multiples of 2.sup.n bytes at different boundary MS absolute addresses,
• executing a plurality of UPS guests simultaneously on different CPUs in the MP under control of a MP control program executable in all CPUs of the MP as a system host, the UPS guests using UPS programs fetchable from the respective UPS copies in MS for execution on the CPUs in the MP,
• providing shareability of the I/O devices for the plurality of UPS guests through a set of shared physical paths.