The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 27, 1976
Filed:
Jun. 06, 1974
Freddie W Wenninger, Loveland, CO (US);
Donald E Morris, Loveland, CO (US);
Jindrich Kohoutek, Loveland, CO (US);
David S Maitland, Loveland, CO (US);
Douglas M Clifford, Loveland, CO (US);
Louis T Schulte, Loveland, CO (US);
John C Keith, Loveland, CO (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
An adaptable calculator is provided by employing five MOS/LSI circuits interconnected by a multiple line bus system. They include (1) a read-only memory circuit group in which subroutines for performing arithmetic and other functions of a basic keyboard input unit are stored; (2) a control and timing circuit for scanning the keyboard, for retaining status information relating to the condition of the calculator or of a particular subroutine, and for generating a next address in read-only memory; (3) an arithmetic and register circuit containing an adder, a group of working registers, a group of data storage registers forming a stack, and a constant storage register; (4) a data storage circuit which provides ten data storage registers, nine of which are employed by the calculator system and one of which is available to the user for storing data; and (5) an input/output (I/O) circuit for enabling the calculator to communicate with various I/O peripheral units such as a typewriter and an X-Y plotter, for performing binary arithmetic by means of a binary arithmetic logic unit contained therein, and for performing various system housekeeping operations. Input and output units include a keyboard input unit having a receptacle for accommodating a 15-key function block to enlarge the capabilities of the calculator and an 18-column output printer unit for printing intermediate results of calculations, entered data, arithmetic operators, and diagnostic notes. An optional 15-digit seven-segment light emitting diode (LED) output display unit may be inserted into the calculator mainframe. All of these input and output units are included within the calculator itself. An X-Y plotter, a typewriter, a marked sense card reader, an extended data storage memory, a magnetic card reading and recording unit, a ASCII bus for enabling the calculator to communicate with data gathering instruments, and many other peripheral input and output units may also be employed with the calculator. The calculator may be operated manually by the user from the keyboard input unit or automatically by a program written in user-level language and stored in a plug-in read-only memory unit (ROM), a plug-in programmable read-only memory unit (PROM) or a read/write memory unit associated with a plug-in magnetic card reading and recording unit.