Computer system and method for operating multiple operating systems in different partitions of the computer system and for allowing the different partitions to communicate with one another through shared memory

(57) Summary computer systems contain two or more treatment modules which can be constituted in a different partition in computer systems, and main memory. Each partition operates under control of a separate operating system. At least one shared-memories window is specified in main memory, and two or more partitions have a right of shared access to this shared-memories window. An exclusion memory window is also assigned to each partition again. With the program code executed on a different partition, these partitions can communicate mutually through a shared-memories window. A means to map the physical address space of the processor in each partition in each exclusion memory window to which it was assigned by each partition is also offered, Therefore, the exclusion memory window assigned to each partition seems to start by the same base address altogether in each operating system performed on those partitions.