ADDRESS CONVERSION SYSTEM

PURPOSE:To access discontinuous areas on a main storage continuously from the view of point a CPU by handling plural segment descriptors with one segment selector value. CONSTITUTION:If an offset value 10 does not exceed the segment size in a segment descriptor 3 indicated by the segment selector value 9 when a real address 11 is calculated from a set of the segment descriptor 3 which has a coupling flag 6 indicating whether or not it is coupled with a segment descriptor 3 at a next position on the main storage 2, the segment selector value 9, and the offset value 10, the coupling flag 6 of the segment descriptor 3 means that the descriptor 3 is not coupled with the next segment descriptor 3 and the processing is interrupted. When the flag 6 indicates that the next segment descriptor 3 is coupled, the real address 11 is calculated again by an address converting means 8. Consequently, plural main storage areas which are discontinuous on the main storage can be handled as one continuous area.