In order to keep track of open files, A-Shell maintains a number of internal buffers, and additional buffer space for ISAM 1.0 files. The number of these is specified with the FILES command in the A-Shell configuration file, and they are allocated within the A-Shell memory partition. The size of the A-Shell memory partition is given by the MEMORY command in the configuration file. If this error appears, either increase the size of the memory partition, or reduce the number of data and ISAM buffers required.