Contiguous Segmentation with Limited Compacting

This paper concerns the problem of implementation of a multi-segment virtual memory with the number of segments variable in time on a memory consisting of one fixed size segment. The segments can differ in size but the size of each segment is invariable in time. For such a memory the following operations are defined: _ creating a segment of a given size, ~ removing an indicated segment, _ address mapping, i.e., calculating a physical address of a memory cell from its virtual address (a virtual address is a pair: segment address and a local address within the segment). Two groups of implementation methods for such a memory are known [ 1,3,5]: _ contiguous segmentation, paged segmentation. The contiguous segmentation is characterised by a simple address mapping operation but its segment creation requires compacting of busy segments in order to create one big free segment out of several smaller free segments. This may lead to a long segment creation time unacceptable for real time systems. E.g., for a total size of compacted segments equal to 50000 and moving (read and