Hewlett-packard Company

William D Eads

Jack M Walden

Louis T Schulte

Daniel J Griffin

Ray J Cozzens

Robert E Kuseski

Martin S Wilson

Robert A Jewett

John L Bidwell

David Steven Maitland

A programmable calculator employs modular read-write and read-only memories separately expandable to provide additional program and data storage functions within the calculator oriented toward the environment of the user and two sixteen bit LSI NMOS central processing units. One of the central processing units (LPU) is employed to perform language syntaxing, arithmetic, and general supervision of program execution. The second central processing unit (PPU) is employed for managing input/output operations. Communication between the two central processing units is accomplished by an arrangement through which the two central processing units share a common portion of memory. The calculator also includes a keyboard having a full complement of alphanumeric keys for entering programs and data into the calculator and for otherwise allowing the user to control operation of the calculator. The keyboard further includes a plurality of user-definable keys, some of which are pre-defined to have certain definitions at the time operating power is applied to the calculator.

Programmable calculator

A programmable calculator employs modular read-write and read-only memories separately expandable to provide additional program and data storage functions within the calculator oriented toward the environment of the user and two sixteen bit LSI NMOS central processing units. One of the central processing units (LPU) is employed to perform language syntaxing, arithmetic, and general supervision of program execution. The second central processing unit (PPU) is employed for managing input/output operations. Communication between the two central processing units is accomplished by an arrangement through which the two central processing units share a common portion of memory. The calculator also includes a keyboard having a full complement of alphanumeric keys for entering programs and data into the calculator and for otherwise allowing the user to control operation of the calculator. The calculator further includes a CRT that can be operated in either an alphanumeric mode or a graphics mode, two magnetic tape transports that permit the user to store information into and to retrieve information from the user portion of the calculator read-write memory, and an 80-column thermal printer utilizing a print head that includes 560 thermal print resistors arranged in a single horizntal row.

Programmable calculator having string variable editing capability

An information transfer bus circuit useful in metal oxide semiconductor integrated circuits employs a network to compensate for signal losses arising from capacitance associated with gating devices in the circuit.

Information transfer bus circuit with signal loss compensation

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Loveland, CO, United States of America

William D Eads