Many users of EDA for ISAM still use legacy applications to update and read their data. To make sure that EDA for ISAM does not lock these applications out or vice versa, Easysoft supports C-ISAM locking modes. Once the locking mode that mirrors your version of C-ISAM is chosen, EDA for ISAM and other applications can access the files concurrently. EDA for ISAM will only take an exclusive lock (and only ever at record level) at point of update. At all other times, EDA for ISAM opens the ISAM file read-only. This ensures that the data is freely available for all other applications.