Abstract: An I/O bus sequencer for providing a data path between an execution Unit (EU-10), a register file (14) and devices connected to a bus (28). A programmable logic array (PLA-18) stores a program which controls a service table (20). The service table includes a plurality of entries divided into fields. One of the fields when decoded instructs the PLA as to what kind of operation the bus sequencer is to perform. Line selection (priority) logic (22) connected to I/O request lines (30) and to the service table (20) determines which service table entry the PLA is to use. A bus interface connected to the I/O bus ports (26) and to the PLA (18) routes data between the I/O bus ports (26) and the register file (14), entries of which are controlled by use of register sets. The service table fields include register set descriptors for storing the status of register set buffers.

Abstract: A communication mechanism for use in a multi-processing system wherein several processors share a common memory. Each processor has associated with it a local communication segment, stored in memory. The local communication segment is for processor-specific communication. Another segment, the global communication segment, is common to all processors, and is for system-wide communication. Each communication segment has a field containing control flags. The flags are set by one processor and later inspected by the same or another processor. The inspecting processor is instructed to perform a number of functions specified by the state of the control flags. A count field and a lock field are provided in all communication segments to interlock access to the communication mechanism. A status field is provided in the local communication segments.

Abstract: A general-purpose, tightly-coupled multiprocessing system wherein processors share a common memory. A hardware-recognizable object (a process object) in memory stores access descriptors for controlling the type and extent of access to objects associated with a process, including one describing a buffered port. Another hardware-recognizable object (a processor object) associated with an executing process, stores access descriptors for controlling the type and extent of access to objects associated with a processor, including one describing a dispatching port. Task-dispatching functions are accomplished by hardware-controlled queuing mechanisms at the buffered ports and dispatching ports. These mechanisms allow different processes to communicate with each other and bind ready-to-run processes with available processors for execution.

Abstract: A data processor architecture wherein the processors recognize two basic types of objects, an object being a representation of related information maintained in a contiguously-addresed set of memory locations. The first type of object contains ordinary data, such as characters, integers, reals, etc. The second type of object contains a list of access descriptors. Each access descriptor provides information for locating and defining the extent of access to an object associated with that access descriptor. The processors recognize complex objects that are combinations of objects of the basic types. One such complex object (a context) defines an environment for execution of objects accessible to a given instance of a procedural operation. The dispatching of tasks to the processors is accomplished by hardware-controlled queuing mechanisms (dispatching-port objects) which allow multiple sets of processors to serve multiple, but independent sets of tasks.