A circulating memory apparatus and a data storage and distribution system
using a circulating recording area effectively and having an improved
access efficiency to the circulating recording area are disclosed. A
memory area secured in a disk unit is used in circulation thereby to
record the time series input data. The time series input data are edited
into a data block of a predetermined size including a plurality of
subblocks, and written into the disk unit by data block. In response to a
request for outputting specific data, the data are read by subblock from
the disk unit into a cache memory thereby to selectively output the
specific data contained in the subblocks.