Adaptable programmed calculator having provision for plug-in keyboard and memory modules
US3971925A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 6, 1974 |
| Grant date | Jul 27, 1976 |
| Priority date | — |
| Expiry date | Jun 6, 1994 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F15/02
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
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 k…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.