Abstract: A file system for managing data files for access by a plurality of users of a data processing system that includes internal storage for buffering, external storage, and a file user interface by which the plurality of users request access to data files. A first level, coupled to the file user interface in the internal storage allocates the internal storage for temporary storage of data to be accessed by the plurality of users, and generates requests for transactions with external storage in support of such allocations. A second level is coupled to the first level and the external storage and responds to the request for transactions with the external storage for managing the transactions for storage of data to, and retrieval of data from, the external storage. The second level defines a plurality of physical storage classes which are characterized by pre-specified parameters that allocate data files subject of transactions to locations in external memory.

Abstract: In a data processing apparatus, having a user domain with domain storage space and an emulation domain with emulation storage space, emulates an instruction in the user domain by calling a program of instructions in the emulation domain. An instruction register connected to receive the sequence of instructions is partitioned into a plurality of fields. At least one field of the instruction register identifies a location for address information for an operand used in execution of the instruction. The instruction is decoded to generate a control code. The control code includes a branch signal to call the emulation program and a domain access control signal to indicate whether the emulation program requires access to the user domain storage base for execution. During execution of the emulation routine, domain access is implied by the location identified for the address information--a set of locations having been preselected as address registers for implied domain addressing.

Abstract: A file system for managing data files for access by a plurality of users of a data processing system that includes internal storage for buffering, external storage, and a file user interface by which the plurality of users request access to data files. A first level, coupled to the file user interface in the internal storage allocates the internal storage for temporary storage of data to be accessed by the plurality of users, and generates requests for transactions with external storage in support of such allocations. A second level is coupled to the first level and the external storage and responds to the request for transactions with the external storage for managing the transactions for storage of data to, and retreival of data from, the external storage. The second level defines a plurality of physical storage classes which are characterized by pre-specified parameters that allocate data files subject of transactions to locations in external memory.

Abstract: In a data processing apparatus, having a user domain with domain storage space and an emulation domain with emulation storage space, emulates an instruction in the user domain by calling a program of instructions in the emulation domain. An instruction register connected to receive the sequence of instructions is partitioned into a plurality of fields. At least one field of the instruction register identifies a location for address information for an operand used in execution of the instruction. The instruction is decoded to generate a control code. The control code includes a branch signal to call the emulation program and a domain access control signal to indicate whether the emulation program requires access to the user domain storage base for execution. During execution of the emulation routine, domain access is implied by the location identified for the address information--a set of locations having been preselected as address registers for implied domain addressing.