Data management systems, such as used in disk control units, employ memory
entry lists to help keep track of user data. Improved performance of
entry list maintenance is provided by the present invention. Much of the
protocol employed to conduct such maintenance is preferably performed by
hardware-based logic, thereby freeing other system resources to execute
other processes. New entries to the memory list are only allowed at
predetermined addresses and entries are updated by writing a
predetermined data pattern to a previously allocated address. Optionally,
improved error detection, such as a longitudinal redundancy check, may
also be performed in an efficient manner during entry list maintenance to
assure the integrity of the list.