Abstract: An information storage system includes a controller for managing the resources of a common mass storage device in order to enable multiple hosts connected to a common bus to independently read and write to the mass storage device in a relatively high speed manner on a first come, real time basis. In particular, a system of commands is provided which enables each host to read and write to the mass storage device on an independent, first come, real time basis by locking the requested address space irrespective of the origination. Even though an address storage space may be locked, the data within such space is always readable by another host. Should a subsequent host issue a command to write to the locked address space, the command is aborted and a flag is set indicating to the subsequent requesting host that the area is locked. The information storage system also provides for dynamic memory mapping which enables the mass storage device to be mapped according to a specific application.