Programmable calculator having string variable editing capability
US4180854A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 29, 1977 |
| Grant date | Dec 25, 1979 |
| Priority date | — |
| Expiry date | Sep 29, 1997 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F15/02
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
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 u…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.