This is an index of all HP patents with Calculator in the title since 1976:
PAT. NO. Title
1 5,530,234 Hand held calculator having a retractable cover
2 4,885,714 Calculator having a user-accessible object stack for the uniform application of mathematical functions and logical operations to a multiplicity of object types
3 4,821,228 Method and apparatus for computation stack recovery in a calculator
4 4,566,072 Programmable calculator including means for digitizing the position of an X-Y plotter pen
5 4,546,448 Programmable calculator including program variable initialization means and definition means array
6 4,480,305 Programmable calculator including editing capability
7 4,456,964 Calculator including means for displaying alphanumeric prompting messages to the operator
8 4,455,618 Programmable calculator
9 4,455,607 Programmable calculator having keys for performing angular measurement unit conversion
10 4,437,156 Programmable calculator
11 4,412,300 Programmable calculator including alphabetic output capability
12 4,384,328 Programmable calculator including magnetic reading and recording means
13 4,381,554 Calculator for storing source data and evaluating numerical answers to problems
14 4,330,839 Programmable calculator including means for automatically processing imformation stored on a magnetic record member
15 4,322,816 Programmable calculator having structure for controlling an x-y plotter
16 4,309,761 Calculator for evaluating numerical answers to problems
17 4,291,385 Calculator having merged key codes
18 4,281,390 Programmable calculator including means for performing computed and uncomputed relative branching during program execution
19 D256,133 Casing for an electronic calculator
20 4,203,152 Programmable calculator including key-log printing means
21 4,198,684 Electronic calculator with keyboard-controlled unary function capability
22 4,197,586 Electronic calculator assembly
23 4,187,547 Programmable calculator including means for controllably introducing blank lines on a printed record during program execution
24 4,181,966 Adaptable programmed calculator including a percent keyboard operator
25 4,181,965 Programmable calculator including program trace means
26 4,180,854 Programmable calculator having string variable editing capability
27 4,178,633 Programmable calculator including multifunction keys
28 4,177,520 Calculator apparatus having a single-step key for displaying and executing program steps and displaying the result
29 4,177,518 Programmable calculator including scrolling alphanumeric display means
30 4,164,039 Programmable calculator including a key for performing either a subtraction or a unary minus function
31 4,164,019 Programmable calculator including alphanumeric display means
32 4,162,532 Programmable calculator including data format display control means
33 4,161,031 Programmable calculator including boolean flag variable means
34 4,159,525 Programmable calculator employing computed memory addresses
35 4,158,285 Interactive wristwatch calculator
36 4,158,233 Programmable calculator including means for performing implied multiply operations
37 4,158,231 Programmable calculator including program listing means
38 4,158,228 Programmable calculator including alphanumeric error display means
39 4,156,921 Adaptable programmed calculator including automatic decimal point positioning
40 4,156,918 Programmable calculator including means for performing computed jumps during program execution
41 4,156,917 Programmable calculator including separate user program and data memory areas
42 4,156,285 Programmable calculator including keyboard functions whose argument may be a numeric constant, a storage register, or an arithmetic expression
43 4,156,282 Programmable calculator including relational operator means
44 4,152,774 Programmable calculator including keyboard function means for raising the number ten to any designated power
45 4,152,773 Programmable calculator including means for establishing a priority for executing algebraic operations
46 4,152,771 Programmable calculator including display means for signalling the user to indicate the exhaustion of a printer paper supply
47 4,152,770 Programmable calculator including means for programmably controlling magnetic storage units
48 4,152,769 Programmable calculator including means for permitting data entry during program execution
49 4,145,752 Programmable calculator including separate line numbering means for user-definable functions
50 4,145,742 Programmable calculator including user-definable keys
51 4,127,897 Programmable calculator having extended input/output capability
52 4,126,898 Programmable calculator including terminal control means
53 D249,243 Wristwatch calculator
54 4,109,315 Wristwatch calculator with selectively scanned keyboard
55 D249,090 Casing for an electronic calculator
56 4,099,246 Calculator having merged key codes
57 4,091,270 Electronic calculator with optical input means
58 4,089,059 Programmable calculator employing a read-write memory having a movable boundary between program and data storage sections thereof
59 4,078,257 Calculator apparatus with electronically alterable key symbols
60 4,075,679 Programmable calculator
61 4,063,221 Programmable calculator
62 4,059,750 General purpose calculator having selective data storage, data conversion and time-keeping capabilities
63 4,055,757 Calculator apparatus with annuity switch for performing begin-and end-period annuity calculations
64 D245,810 Casing for an electronic calculator
65 4,047,012 General purpose calculator having factorial capability
66 4,037,092 Calculator having preprogrammed user-definable functions
67 D245,107 Electronic calculator
68 4,035,627 Scientific calculator
69 D244,862 Casing for an electronic calculator
70 4,028,538 Programmable calculator employing algebraic language
71 4,012,725 Programmable calculator
72 4,009,379 Portable programmable calculator displaying absolute line number addresses and key codes and automatically altering display formats
73 4,001,569 General purpose calculator having selective data storage, data conversion and time-keeping capabilities
74 3,996,562 Programmable electronic calculator for evaluating mathematical problems
75 3,987,290 Calculator apparatus for displaying data in engineering notation
76 3,971,925 Adaptable programmed calculator having provision for plug-in keyboard and memory modules
77 3,955,074 General purpose calculator having keys with more than one function assigned thereto
78 3,946,218 General purpose calculator with capability for performing yield-to-maturity of a bond calculation