Abstract: An Integrity Server computer for economically protecting the data of a computer network's servers, and providing hot standby access to up-to-date copies of the data of a failed server. As the servers' files are created or modified, they are copied to the Integrity Server. The invention provides novel methods for managing the data stored on the Integrity Server, so that up-to-date snapshots of files of the protected file servers are stored on low-cost media such as tape, but without requiring that a system manager load large numbers of tapes.

Abstract: A data processing system in which macroinstructions are decoded to provide a sequence of microinstructions comprising one or more microroutines. A stack storage means stores data for use in such microroutines. The final microinstruction of the microroutines is a request to retrieve or remove data from the stack. When no data is present therein (the stack is empty) a new macroinstruction is requested and when data is present in the stack the microroutine returns to another mircoroutine in which it is acting as a micro-subsroutine to permit continuation of the other microroutine.

Abstract: A data processing system which handles thirty-two bit logical addresses which can be derived from either sixteen bit logical addresses or thirty-two bit logical addresses, the latter being translated into physical addresses by unique translation means. The system includes means for decoding macro-instructions of both a basic and an extended instruction set, each macro-instruction containing in itself selected bit patterns which uniquely identify which type of instruction is to be decoded. The decoded macro-instructions provide the starting address of one or more micro-instructions, which address is supplied to a unique micro-instruction sequencing unit which appropriately decodes a selected field of each micro-instruction to obtain each successive micro-instruction. The system uses hierarchical memory storage using eight storage segments (rings), access to the rings being controlled in a privileged manner according to different levels of privilege.

Abstract: A data processing system which handles thirty-two bit logical addresses which can be derived from either sixteen bit logical addresses or thirty-two bit logical addresses, the latter being translated into physical addresses by unique translation means. The system includes means for decoding macro-instructions of both a basic and an extended instruction set, each macro-instruction containing in itself selected bit patterns which uniquely identify which type of instruction is to be decoded.

Abstract: A data processing system which handles thirty-two bit logical addresses which can be derived from either sixteen bit logical addresses or thirty-two bit logical addresses, the latter being translated into physical addresses by unique translation means. The system includes means for decoding macro-instructions of both a basic and an extended instruction set, each macro-instruction containing in itself selected bit patterns which uniquely identify which type of instruction is to be decoded. The decoded macro-instructions provide the starting address of one or more micro-instructions, which address is supplied to a unique micro-instruction sequencing unit which appropriately decodes a selected field of each micro-instruction to obtain each successive micro-instruction. The system uses hierarchical memory storage using eight storage segments (rings), access to the rings being controlled in a privileged manner according to different levels of privilege.