Abstract: A control apparatus for a switching regulator circuit having a voltage controlled oscillator responsive to any deviation of the output voltage of the switching regulator circuit from a predetermined reference voltage. The voltage controlled oscillator produces a digital pulse stream having a frequency which is varied by the voltage controlled oscillator in response to any deviation of the output voltage of the switching regulator circuit from the predetermined reference voltage. A recovery detector is connected to at least one of the reactors of the switching regulator circuit to ensure that the particular SCR associated with that reactor has fully recovered prior to the next actuation thereof. If the particular SCR has not recovered then the digital pulse which would be distributed to that SCR within the digital pulse stream is held.

Abstract: A memory subsystem which couples to a multiword bus for processing memory requests received therefrom includes at least a pair of independently addressable dynamic memory module units. Each memory unit includes a number of rows of random access memory (RAM) chips. The subsystem receives as part of each memory request an address, the least significant portion of which selects the row of chips to be accessed within one of the pair of memory units. Address decode circuits include gating circuits which couple to both module units. The gating circuits are interconnected so that the decoding of the least significant address bits results in the generation of a pair of row address strobe signals. These signals enable simultaneously the rows of RAM chips for access within both module units for read out of information to a multiword bus eliminating any delay in address incrementing.

Abstract: In a data processing system, a central subsystem includes a plurality of special purpose processing units with one of the processing units serving as a control processing unit within a central subsystem. The processing units are coupled to a common subsystem bus for the transfer of data, control information, and address information within the central subsystem. Access to the subsystem bus is allocated by a bus control unit which also interfaces the central subsystem with other processing units such as a system memory or system I/O devices that are included in the data processing system.

Abstract: In a data processing system, a self-diagnosing system selectively initiates the operation of subprocessing units in the data processing system in a predetermined sequence to determine whether the subprocessing units are operating correctly. A control store stores a plurality of sequences of control data which are selectively accessed to control the operation of the subprocessing units to perform self-diagnosing error tests. A display unit displays an indication of which of the sequences of control data is currently controlling the operation of the subprocessing units in order to aid error diagnosis should an error be discovered during the operation of the self-diagnosing system.

Abstract: An apparatus is disclosed herein for providing faster memory access for a CPU by utilizing a least recently used scheme for selecting a storage location in which to store data retrieved from main memory upon a cache miss. A duplicate directory arrangement is also disclosed for selective clearing of the cache in multiprocessor systems where data in a cache becomes obsolete by virtue of a change made to the corresponding data in main memory by another processor. The advantage of higher overall speed for CPU operations is achieved because of the higher hit ratio provided by the disclosed arrangement. In the preferred embodiment, the cache utilizes: a cache store for storing data; primary and duplicate directories for identifying the data stored in the cache; a full/empty array to mark the status of the storage locations; a least recently used array to indicate where incoming data should be stored; and a control means to orchestrate all these elements.

Abstract: A microprogrammed data processing system includes a cache memory, a decimal unit and an execution unit. The decimal unit receives operands from cache memory, strips the non-decimal digit information from the operands, and assembles the 4-bit decimal digits from the operand into words containing a maximum of 8 decimal digits for transfer to the execution unit. The execution unit processes the words in accordance with a decimal numeric instruction. The throughput of the system is increased when processing short operands which contain 15 decimal digits or less by apparatus in the decimal unit which detects the short operand and determines the number of cache memory cycles between the cycle the first word of the short operand is received from cache memory and the cycle on which the first assembled word is transferred to the execution unit for processing.

Abstract: In a data processing system which includes a central processing unit (CPU), main memory and a plurality of input/output controllers (IOCs) connected to a common bus information can be transferred between the main memory and CPU and main memory and the IOCs. Logic is provided within the CPU to align a byte of data on the data lines of the common bus such that it can be taken from the data lines by the main memory and written into a multi byte word without further alignment. Logic is provided within the CPU to extract from a multi byte word of data read from main memory and appearing on the common bus data lines the appropriate byte of data and to align it on the common bus data lines such that an IOC may pass the data byte to a peripheral device without further alignment.

Abstract: A generalized event management architecture based upon an analysis of the traditional interprocess communication and synchronization mechanisms is disclosed. An extended semaphore architecture is proposed which combines the properties of Dijkstra's semaphore with that of a trap facility. This model is further developed into a more general architecture capable of handling complex events, structured event condition variables and generalized assignments. The architecture is defined in terms of entity classes, relationship classes and functional primitives. Finally a typical hardware computer system utilizing these concepts is shown and described.

Abstract: Digital data is recorded on the surface of a magnetic media such as a disk or diskette in the form of magnetic flux transitions identifying clock and data information in either a frequency modulation (FM) mode or a modified frequency modulation (MFM) mode. A read head senses the flux transitions which are in turn converted to digital signals. Apparatus converts the time between successive digital signals into PROM addresses. The PROM address locations store coded signals identifying the data as binary ONE or binary ZERO signals.

Abstract: One or more queue structures in a data processing system may include a threaded list of frames which are enqueued or dequeued from the list in accordance with four instructions wherein each list is tied to a so-called lock or control frame with synchronization for multiple processing units. Multiple lock frames and accordingly multiple lists of frames may be coupled in the system for the purpose of accomplishing the various tasks necessary.

Abstract: An automatic purge control for a banknote dispensing system including an operator panel having a keyboard for initiating transaction requests, a dispensing chamber adjacent to the panel for receiving banknotes dispensed in response to an operator request, a lockable access door to enable the operator to gain access to the chamber to remove dispensed notes, and a tiltable platform positioned within the chamber for discharging dispensed notes from the chamber under predetermined purge conditions detected by a microprocessor within the system. The microprocessor calls for a purge operation when it has been determined that the operator has either failed to remove dispensed notes or has left notes within the chamber. Interlocks are provided on the purge apparatus for inhibiting continued operation of the dispensing system if a purge cycle is improperly executed.

Abstract: A memory subsystem couples to a single word bus in common with a central processing unit for processing memory requests received therefrom. The subsystem includes at least a pair of independently addressable dynamic memory module units. Each memory unit includes a number of rows of random access memory (RAM) chips. The subsystem receives as part of each memory request an address, the least significant portion of which specifies the row of chips to be accessed within a first one of the pair of memory units. The subsystem further includes control circuits, common timing circuits and common addressing circuits. The addressing circuits which couple to both module units provide the required address signals to both modules for enabling the simultaneous access of a pair of words therefrom.

Abstract: A method and apparatus for detecting a deadlock condition where two or more processes are waiting for events which cannot happen. Firmware is provided to examine the request of a first process of a group of processes for assignment of a first resource of a group of resources, and to determine whether said first resource is or is not currently assigned to a second process of said group of processes which said second process is already waiting directly or indirectly for a second resource of said group of resources which said second resource is currently assigned to the said first process.

Abstract: In a data processing system which includes a central processing unit and one or more main memory units for storing program software instructions and program data, logic is provided within the CPU to signal the main memory units, comprised of semiconductor random access memory chips, that a memory refresh operation can be performed. The logic is organized such that the memory refresh operation signal may be given to the main memory units in parallel with and without detracting from other CPU operations. Further, logic is provided within the CPU to interrupt the CPU normal processing and perform a memory refresh operation if one has not been performed with a predetermined time period. Logic is provided within each main memory unit to accept the memory refresh signals from the CPU and to discard those memory refresh signals that would refresh the memory more frequently than required to retain the memory contents thus reducing main memory power consumption.

Abstract: An adapter includes free running low power clock circuits connected to provide a time of day value accessible by a central processing unit which couples to the adapter through a controller subsystem. The adapter cicuits are constructed on a circuit board which is installed as part of the controller subsystem. The clock circuits are connected to one terminal of a battery power supply whose other terminal connects to an interface connector included within the adapter. Upon installing the adapter board in the subsystem, the battery power supply is connected to provide power for operating the clock circuits. When the adapter is removed from the subsystem, the battery power supply is disconnected, preventing it from discharging. The adapter includes an adapter connector for connecting the output terminal of the battery power supply to enable the battery to be charged or its power level monitored when the adapter circuit board is installed.

Abstract: A badge reader logic system is provided for receiving binary coded information read from a badge, card or other recording medium having data encoded thereon by means of bistable magnetic wire patterns, and reformatting such binary coded information into a two-dimensional data matrix row and column format for processing by a local controller. The binary coded information further is interrogated in time relation with logic signals received from sensors placed along an insertion path of the badge into the badge reader to detect unauthorized badges, incorrect badge orientations and other error conditions.

Abstract: A cache unit includes a cache store organized into a number of levels to provide a fast access to instructions and data words. Directory circuits, associated with the cache store, contain address information identifying those instructions and data words stored in the cache store. The cache unit has at least one instruction register for storing address and level signals for specifying the location of the next instruction to be fetched and transferred to the processing unit. Replacement circuits are included which, during normal operation, assign cache locations sequentially for replacing old information with new information. The cache unit further includes detection apparatus for detecting a conflict condition resulting in an improper assignment. The detection apparatus, upon detecting such a condition, advances the relacement circuits forward for assigning the next sequential group of locations or level inhibiting it from making its normal location assignment.

Abstract: A data processing system comprises a data processing unit coupled to a cache unit which couples to a main store. The cache unit includes a cache store organized into a plurality of levels, each for storing blocks of information in the form of data and instructions. The cache unit further includes control apparatus, an instruction buffer for storing instructions received from main store and a transit block buffer comprising a plurality of locations for storing read commands. The control apparatus includes a plurality of groups of bit storage elements corresponding to the number of transit buffer locations. Each group includes at least a pair of instruction fetch indicator elements which are operatively connected to control the writing of first and second blocks of instructions into the instruction buffer.