US3693162A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Subroutine call and return means for an electronic calculator
Assignee: HP Inc
•
Filing: 1970-10-14
•
Granted: 1972-09-19
•
Expires: 1990-10-14
Abstract
Abstract Two electronic calculator keys provide unconditional GO TO and subroutine call/return and return functions. A GO TO instruction followed by an alpha-numerical address causes the calculator to unconditionally branch to the address indicated. The GO TO instruction followed by a SUB instruction and an alpha-numerical address causes the calculator to unconditionally branch to a subroutine at the address indicated, and the SUB instruction alone causes the calculator to unconditionally branch (return) to the address it was at when it branched to the subroutine.
Inventors
- 👤 Richard M Spangler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 06:27
CPC Classifications
G; G06; G06F; G06F15/00; G06F15/02
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
366 words
An electronic calculator comprising: a keyboard having a plurality of keys including alpha numeric, functional and instructional keys, and having encoding means for generating a key code signal for each key in response to a key being depressed, the key codes being available at a keyboard output; a buffer storage register; a memory having a plurality of addressable locations having key codes stored at selected ones of the locations; a program counter connected to the memory for selecting memory locations in a predetermined sequence, the contents of said selected memory locations being available at a memory output; an intermediate storage register; decoding means connected to the encoding means and the memory for decoding the key code signals; first logic means connected to the keyboard, memory, decoding means and intermediate storage register for storing a first instructional key code signal from the keyboard or memory output, the first signal being available at a first output, and for storing a second signal in the intermediate storage register in response to the presence of said first signal at the first output and a second instructional key code from the keyboard or memory output, the second signal being available at a second output; second logic means connected to the intermediate storage register, keyboard, memory, decoding means, buffer storage register and program counter for setting the program counter to a new memory location in response to the presence of the second signal at the second output of the first logic means and an alpha numeric key code at the keyboard or memory output, this key code indicating the new memory location, and for storing in the buffer storage register the memory location selected by the program counter immediately preceding the new memory location to which the program counter is set by the second logic means; and third logic means connected to the program counter, buffer storage register, intermediate storage register and decoding means for setting the program counter to the memory location stored in the buffer storage register in response to the absence of the first signal at the first output of the first logic means and a signal from the decoding means in response to the second instructional key code.
Claim 2
Dependent Claim
366 words
An electronic calculator comprising: a keyboard having a plurality of keys including alpha numeric, functional and instructional keys, and having encoding means for generating a key code signal for each key in response to a key being depressed, the key codes being available at a keyboard output; a buffer storage register; a memory having a plurality of addressable locations having key codes stored at selected ones of the locations; a program counter connected to the memory for selecting memory locations in a predetermined sequence, the contents of said selected memory locations being available at a memory output; an intermediate storage register; decoding means connected to the encoding means and the memory for decoding the key code signals; first logic means connected to the keyboard, memory, decoding means and intermediate storage register for storing a first instructional key code signal from the keyboard or memory output, the first signal being available at a first output, and for storing a second signal in the intermediate storage register in response to the presence of said first signal at the first output and a second instructional key code from the keyboard or memory output, the second signal being available at a second output; second logic means connected to the intermediate storage register, keyboard, memory, decoding means, buffer storage register and program counter for setting the program counter to a new memory location in response to the presence of the second signal at the second output of the first logic means and an alpha numeric key code at the keyboard or memory output, this key code indicating the new memory location, and for storing in the buffer storage register the memory location selected by the program counter immediately preceding the new memory location to which the program counter is set by the second logic means; and third logic means connected to the program counter, buffer storage register, intermediate storage register and decoding means for setting the program counter to the memory location stored in the buffer storage register in response to the absence of the first signal at the first output of the first logic means and a signal from the decoding means in response to the second instructional key code.
References Cited (Backward Citations)
US3238505A
Cited
US3158317A
Cited
US3187321A
Cited
US3495222A
Cited
US3380031A
Cited
US3381276A
Cited
US3487369A
Cited
US3533076A
Cited
US3530440A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-09-19 | 1976-03-20 | 1976-09-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-19 | 1980-03-20 | 1980-09-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-19 | 1984-03-20 | 1984-09-19 | $7700.00 | Window Closed / Lapsed |