According to the invention, a microprocessor computing system comprises at least one data processing device and at least one group of execution control elements; said group constitutes a control level and includes at least one microprogram control device which is a group of first-order control elements. The data processing device incorporates a microinstruction register for holding microinstruction codes, a microoperation decoder, a general-purpose register unit for holding operands, an arithmet...

A highly parallel microprocessor using a logic gating structure and a microinstruction organization which permits direct access by each of the microprocessor components to a tri-bus system. Operation is defined by a single phase clock, during which all portions of a microinstruction are executed. The system further permits overlap operation for microprocessor instructions, thereby allowing for the fetching of a next instruction while executing a current instruction. The use of general purpose, n...

An apparatus for testing circuit board systems utilizing microprocessors which includes means for selectively exercizing each terminal or pin of the board system during each step of the testing protocol. Each step of the protocol can be preselected to operate according to an automatic sequence or according to a preprogrammed manner, or the apparatus may be conditioned to receive a response from the circuit board system at a selected terminal during a selected step of the testing protocol. The te...

A microprocessor system includes a microprocessor, a memory, and an interface adaptor all coupled to a data bus. The interface adaptor is coupled between the data bus and a peripheral device, such as a teleprinter. A first interrupt conductor is connected to the peripheral device and to interrupt logic circuitry in the interface adaptor. A second interrupt conductor is connected to the microprocessor and the interrupt logic circuitry. The interrupt logic circuitry is also coupled to and interrog...

A single bit recycling microprocessor which performs sequential and combinational logic equations. The microprocessor has exclusive input and output instructions and performs three basic logic operations, two of which are performed concurrently on each data input. The processor substitutes read only memory (ROM) for a network of logic gates, multiplexers, decoders, flip-flops and counters. The simulation of J-K flip-flops is accomplished by a tandem operation of two R-S flip-flops.

A microprocessor configuration includes a central control and processing unit, a bus having a bus state line and data/address lines, and units connected to the bus. If none of the units is being addressed by the control and processing unit, random data values are transmitted on the data/address lines. Such a process and configuration masks the current profile of the microprocessor configuration with regard to the useful information to be transmitted through the bus.

A display system for displaying information in response to an input video signal comprises a data control unit including a microprocessor and a microprogram memory for storing a program for the microprocessor, a refresh memory unit connected to the data control unit through an address bus and a data bus, and a video control unit for accessing display data stored in the refresh memory unit by a timing control unit to produce a video signal. The refresh memory unit comprises memories sectioned by ...

A microprocessor for executing computer programs which have been enciphered during manufacture to deter the execution of the programs in unauthorized computers. This microprocessor deciphers and executes an enciphered program one instruction at a time, through a combination of substitutions, transpositions, and exclusive-OR additions, in which the address of each instruction is combined with the instruction. Each unit may use a unique set of substitutions so that a program that can be executed i...

The present invention relates to method and apparatus for providing a communication arrangement between two or more independently operable microprocessor units (MPUs). Large amounts of data or data in block format are capable of being passed between MPUs via the present intercommunication channel with little handshaking between MPUs. In the present arrangement, a plurality of MPUs sequentially access, under the control of a synchronous clock, a common memory for random access to blocks of memory...

A microprocessor is utilized to monitor and control the operation of an image projector and a magnetic tape cassette player. Inaudible cueing tones recorded on the tape allow the recorded narrative to be kept in synchronization with the image projected. A sync counter within the microprocessor keeps track of the amount and direction by which the image and tape are out of synchronism. The microprocessor controls a visual indication to the operator that shows the direction in which the tape must b...