Abstract: A multiprogrammable/multiprocessing digital computer system having a process control block for each process in the system, wherein each process control block includes information which specifies the state of a processor at any given time. Associated with each process control block is a decor extension table having information to indicate whether a specified function, such as the emulation of another processor, may be executed in the system. A native mode instruction indicating a specified function for either one instruction or for a plurality of instructions, is first checked to determine proper format, after which a determination is made by means of the decor extension table, as to whether or not the system is capable of executing the specified function indicated by the native mode instruction.

Abstract: There is disclosed an input/output controller for an information processing system comprising a main memory, a central processing unit, a peripheral controller and a plurality of peripheral units coupled to the central processing unit. In particular, the input/output controller comprises a plurality of physical channels disposed between the peripheral controller and the central processing unit, a plurality of logical channels for transmitting information with the central processing unit, and each uniquely associated with one of the peripheral units. The main memory stores a first table including a physical channel entry containing informaton relative to the plurality of physical channels and a second table including a logical channel entry containing information relative to the plurality of peripheral units.

Abstract: A first test and diagnosis device to check a data processing unit. The device includes means for manually testing and passing diagnostics on the first unit, as well as other means for automatically testing and diagnosing the first unit through a second data processing unit. The latter means are comprised of maintenance circuitry, contained within the first unit and linked to the second unit in such a way as to allow the second unit to conversationally interact with the first unit. This interaction is comprised of a sequence of input and output microdialogues performed by means of the maintenance circuits. The test and diagnosis microprograms may be contained in either unit.

Abstract: Apparatus and process for the rapid processing of the data in a data processing system having a segmented memory, wherein descriptors representing the characteristics of the segments are employed in retrieving from memory and processing each segment, and wherein means is provided for the rapid locating of the descriptors for the segments most frequently utilized.