- 119 Practical Programs for the TRS-80 Pocket Computer
John Clark Craig's book of short BASIC programs for the PC-1 and PC-1211 (TAB Books).
- A 240-Character Vacuum Fluorescent Display (SID Digest, 1979)
Ise's SID paper on a 240-character dot-matrix fluorescent display, the step beyond calculator digits.
- A Closer Look at the Compensating Polar Planimeter (Eggers, 2020)
College Mathematics Journal 51:2 (2020): the mathematics of the compensating polar planimeter, showing that averaging pole-left and pole-right readings exactly cancels a misaligned wheel.
- A Contribution to the History of Planimeters (Vossepoel & Zerfowski, 2023)
Slide Rule Gazette 23 (2023): more than 30 lesser-known planimeters of 1814–1884.
- A History of Pocket Computers 1980–2000
Roland Saam's paper for IEEE HISTELCON 2019 on the pocket computers of 1980–2000, their makers, prices and uses.
- A Treatise on Planimeters: Theory, History and Different Varieties (Frost, 2025)
Lecture slides from the Oughtred Society's 2025 international meeting: the history, theory and many varieties of planimeter.
- ACT Calculator Policy
ACT's calculator policy: which calculators are allowed and prohibited in the ACT test.
- AGS 14 Calculator: Reverse-Engineered Schematic
Schematic of the AGS 14 pocket calculator of 1975 with a nine-digit fluorescent tube.
- AL304 Seven-Segment LED Indicator Datasheet (in Russian)
Datasheet of the AL304 gallium-arsenide-phosphide seven-segment LED digit of the kind used in early Soviet LED calculators (in Russian).
- American Planimeters (Otnes, 2002)
Journal of the Oughtred Society 11:2 (2002): the planimeters sold in America, K&E's suppliers (Amsler, Coradi, Haff, Ott), and their uses.
- Busicom Calculator with Mostek Chips: TCD Treasures Catalogue Entry
Trinity College Dublin's catalogue entry for a Busicom calculator, with Joerg Woerner's notes on the Mostek MK6010 and MK50xx chips: 25 V and 15 V processes, digit times of four clocks and scan cycles of fifteen digit times.
- BYTE, January 1981: Hand-Held Computers
Pages from BYTE's hand-held computer issue of January 1981, on the TRS-80 Pocket Computer and its rivals.
- BYTE, January 1981: Sharp PC-1211
BYTE's pages on the Sharp PC-1211 from its January 1981 issue.
- Canon 163 Calculator: Reverse-Engineered Schematic
A 22-page schematic of the Canon 163 Nixie calculator of c. 1968-69, drawn from two working machines: block diagram, timing, the torsional delay line and its amplifiers, TI DTL logic, the 1-2-4-2 serial adder, the multiplexed Nixie display and the +100/+200 V display supplies.
- Canon 163 Calculator: Schematic Appendix
Nine pages of supporting drawings for the Canon 163 schematic: flip-flop forms, timing diagrams, the register and delay-line organisation, state graphs and a worked square root.
- Canon 163 Calculator: Theory of Operation
A 21-page theory of operation written from the reverse-engineered schematic and a logic simulation: the 1 MHz crystal clock, six registers in one delay line, the 1-2-4-2 code, the state machine, number entry, memories, the multiplexed display, and servicing notes (board insertion, forcing states to trace delay-line faults).
- Canon Canola 1200 Logic and Timing Manual
Canon's logic and timing manual for the Canola 1200 Nixie calculator: logic flow, timing diagrams, chip pinouts and schematics.
- Casio 121-B Calculator: Reverse-Engineered Schematic
A 10-page schematic of the Casio 121-B of 1970: Hitachi HD3100 PMOS chips, the NEC uPD116C Nixie decoder-driver, Toshiba high-voltage drivers and multiplexed Hitachi CD-71 Nixies.
- Casio AL-1000 Calculator: Reverse-Engineered Schematic
A 26-page schematic of Casio's programmable AL-1000 of 1967: discrete DTL, core memory for numbers and program, and multiplexed NEC LD-866 Nixies.
- Casio CQ-1 Computer Quartz Instruction Manual
Instructions for the Casio CQ-1, the first calculator with a built-in clock: clock, alarm, stopwatch and calculator functions.
- Casio fx-101 Instruction Manual
Instructions for the Casio fx-101 scientific with its green Digitron tube: scientific notation, memory, functions and worked examples.
- Casio fx-102 Instruction Manual
Instructions for the Casio fx-102 scientific calculator, a relative of the fx-101.
- Casio fx-110 Instruction Manual
Instructions for the Casio fx-110 scientific calculator.
- Casio fx-115ES / fx-991ES User's Guide
Casio's user's guide for the fx-115ES and fx-991ES, the top models of the original ES series.
- Casio fx-120 Instruction Manual
Instructions for the Casio fx-120 scientific calculator.
- Casio fx-21 Instruction Manual
Instructions for the Casio fx-21 scientific calculator with its Digitron tube panel (English and Spanish).
- Casio fx-570ES PLUS / fx-991ES PLUS User's Guide
Casio's user's guide for the fx-570ES PLUS and fx-991ES PLUS, the larger ES calculators with equations, complex numbers, matrices, vectors, integration and differentiation, and the calculation ranges and methods.
- Casio fx-570EX / fx-991EX ClassWiz User's Guide
Casio's user's guide for the fx-570EX and fx-991EX ClassWiz, the successors of the ES series.
- Casio FX-702P Brochure (Italian)
An Italian brochure for Casio's FX-702P, its first BASIC pocket computer.
- Casio fx-82ES/83ES/85ES/300ES/350ES User's Guide
Casio's English user's guide for the fx-82ES family (RCA502136-001V01): modes, setup, Natural Display input, fractions, percentages, memories, statistics, tables, specifications and battery replacement.
- Casio fx-82ES/83ES/85ES/300ES/350ES User's Guide Appendix
The appendix to Casio's fx-82ES user's guide (RCA502155-001V01), with the key sequences for its numbered examples.
- Casio fx-82MS/85MS/220PLUS/300MS/350MS User's Guide
Casio's user's guide for the fx-82MS family, the two-line S-V.P.A.M. generation before Natural Display.
- Casio Personal-8 Calculator: Reverse-Engineered Schematic
Schematic of the Casio Personal-8 of 1975: Hitachi HD3679 single chip driving an NEC LD8120 tube directly, Fuji MPS 0606 converter giving -6, -14, -22 and -29 V and 1.4 V AC filament from 3 V, 1.67 kHz scan.
- Casio personal-mini Instruction Manual
Instructions for the Casio personal-mini with its six-digit Digitron tube: two-part display of twelve-digit results, automatic constant, overflow, batteries and adapter.
- Casio Pocket Computers Brochure
Casio's brochure for its range of pocket computers.
- Casio pocket-mini Instruction Manual
Instructions for the Casio pocket-mini with its multi-Digitron tube panel.
- Cathode Ray Tube Phosphors Of Interest To The Experimenter (rev. 20100226)
A compilation of CRT phosphor P-numbers with colour and persistence.
- CDK C1HB Calculator: Reverse-Engineered Schematic
Schematic of the CDK C1HB desk calculator of 1977: a TI TMS1273 driving an Itron FG139A3 tube directly through 100 k pull-downs to -35 V, with a blocking-oscillator supply.
- Commodore Custom Green Line Operating Instructions (997R, 996R, 994R, 97D, 96D, 94D)
Operating instructions for the Commodore Green Line fluorescent pocket calculators: keys, constants, exchange key, percent, memory and interest examples.
- Compensating Polar Planimeters 4236, 4236M, 4237, 4242 & 4242½ (K&E manual, 1949/1957)
K&E's 32-page manual for its fixed-arm and adjustable compensating polar planimeters, including the 4242½: care, setting up, reading the dial, wheel and vernier, tracing, scale factors, indicator diagrams, pole-inside measurement with the neutral circle, accuracy, the testing rule, tracer-arm settings tables and graph, and the calculus theory.
- Computing Examples for the Curta Calculating Machine
Contina's worked-examples booklet for the Curta: the four basic operations and the short-cut methods built on them, shown step by step with dial settings. Scanned copy; the text layer is OCR and carries errors. Undated; it covers the Model II, so it postdates that model's introduction.
- Curta Calculating Techniques
A loose-leaf set of Curta methods issued free by the British agent, Automatic Business Machines Ltd of London: general techniques, commercial work in sterling, engineering examples, and mathematical procedures such as roots, polynomials and series, with numbered Curta tables. Scanned copy; the text layer is OCR and carries errors. Undated; it covers both models and works in pre-decimal sterling, so it predates February 1971.
- Curta Computing Methods — Business and Statistical Examples, with Five-Place Logarithm Tables
A Curta calculating handbook that opens with a product description and goes on to business methods, statistics on grouped data, and five-place logarithm tables. The scan has a blank cover and no title page, so the title given here is descriptive. The text layer is OCR and carries errors. Undated.
- DE Patent 194,527: Rechenmaschine (C. Hamann, the Gauss)
The modified form of Hamann's round calculating machine, the Gauss, with its setting mechanism arranged radially around a central axis. German twin of US 832,666.
- DE Patent 209,817: Rechenmaschine (C. Hamann, the proportional lever)
Hamann's proportional lever, filed 1906 and published 1909, the mechanism of the Mercedes-Euklid. German twin of US 1,011,617.
- DE Patent 287,770: Rechenmaschine (C. Hamann, Mercedes-Euklid automatic multiplication and division)
Hamann's patent of 1914–15 that gave the Mercedes-Euklid automatic multiplication and division.
- DE Patent 367,726: Rechenmaschine (Deutsche Telephonwerke, the switching latch)
The first switching-latch patent, filed 24 October 1920 and published 25 January 1923: gear wheels engaged by a latch for a number of teeth set by a stationary disk, instead of pinwheels, with the tens carry made by the drum itself.
- DE Patent 384,150: Rechenmaschine (Deutsche Telephonwerke, one wheel per place)
Filed 24 February 1923: the one-wheel-per-place switching latch, with internal and external teeth on each wheel, the fixed disk and settable segment that form the latch's track, anti-overrun locks and the setting indicator.
- DE Patent 432,435: Rechenmaschine (Deutsche Telephonwerke, automatic division)
Filed 19 December 1924: automatic division with the crank turning one way for every operation, by a reversing gear and a half-step carriage movement. German twin of US 1,788,192.
- DE Patent 443,479: Rechenmaschine (Deutsche Telephonwerke, reversible revolutions counter)
Filed 4 March 1926: the reversible revolutions counter, with the counter lever's + and − positions holding the two-armed counting finger on one side or the other.
- DE Patent 468,275: Rechenmaschine (Deutsche Telephonwerke, counter tens carry)
Filed 4 March 1926: the tens carry for the revolutions counter, the change from the Manus A to the B.
- DE Patent 748,500: Rechenmaschine (C. Hamann, back-transfer)
Hamann's 1940 back-transfer patent, carrying a result back into the setting levers.
- DE Patent 88,223: Führung der Mess- oder Zählrolle an Instrumenten (C. Hamann, planimeter)
Hamann's patent of 11 June 1895, from his instrument workshop in Friedenau, Berlin: a guide for the measuring wheel of planimeters and integrators, using an isosceles slider-crank in place of the Amsler polar or Wetli linear mechanisms.
- DE Patent 919,787: Rechenmaschine (C. Hamann, back-transfer of the Manus R)
Christel Hamann's last major patent, filed 29 October 1949: the back-transfer device of the Manus R.
- Dempa Shimbun, 21 July 1967: Ise to Mass-Produce the Digitron (with English translation)
A Japanese trade-paper report that Ise Electronics would soon mass-produce its new numeric display tube, the 'Digitron', developed with Hayakawa Electric and driven at only 25 V, with an English translation.
- Die Klassifizierung mechanischer Rechenmaschinen, Teil 3: Schaltwerksprinzipien
Haertel's classification of the actuating mechanisms of mechanical calculators (3rd ed., in German): stepped drum, pinwheel, proportional lever, switching latch and the rest, crediting Christel Hamann with the switching latch.
- Die Planimeter: deren Theorie, Praxis und Geschichte (Trunk, 1865)
A German history and theory of the planimeters known by 1865, from Hermann and Oppikofer to Amsler.
- Electronics Today International, July 1975
The British magazine Electronics Today International for July 1975, with coverage of Sinclair's calculators.
- Electronics, 29 May 1967: Ise's Low-Voltage Numerical Display Tube
The first public report of Ise Electronics' vacuum-fluorescent numerical tube, from Electronics magazine of 29 May 1967, pp. 212-213.
- Elektronika 155 Passport and Operating Instructions (Russian)
The passport and operating instructions of the Elektronika 155 desk calculator, for economic, statistical, scientific and design calculations (in Russian).
- Elektronika B3-02 Passport (Russian)
The fourteen-page passport of the Elektronika B3-02 desk calculator, an electronic keyboard computing machine (ЭКВМ) with a fluorescent display (in Russian).
- Elektronika B3-14 Circuit Diagram
The circuit diagram of the B3-14 fluorescent-display pocket calculator (in Russian).
- Elektronika B3-18A Circuit Diagram
The two-sheet circuit diagram of the B3-18A scientific pocket calculator, with the K145IP7 chip (in Russian).
- Elektronika B3-18A Operating Manual (Russian)
The operating manual of the B3-18A, the improved version of the first Soviet pocket scientific calculator (in Russian).
- Elektronika B3-21 Operating Manual (Russian)
The 79-page Russian operating manual of the B3-21, the first Soviet pocket programmable calculator (in Russian).
- Elektronika B3-21 Passport (Russian)
The seven-page passport of the B3-21 (in Russian).
- Elektronika B3-26 Circuit Diagram
The circuit diagram of the B3-26 four-function calculator on the K145IP11 chip (in Russian).
- Elektronika B3-26 Passport (Russian)
The four-page passport of the B3-26 four-function pocket calculator (in Russian), digitised by a collector from his own copy.
- Elektronika B3-34 Factory Circuit Diagram (two sheets)
The two-sheet factory schematic of the B3-34: K145IK1302/1303, K145IR2 and K165GF3 chips, the converter and BP2-3 mains unit, the IVL2-8/12 tube with its parameter table, oscillograms, and the note on fitting VD4 forward for a weak display (in Russian).
- Elektronika B3-34 Operating Manual (Russian)
The 165-page Russian instruction booklet of the B3-34 programmable calculator (in Russian).
- Elektronika B3-35 Operating Manual (Russian)
The 67-page operating manual of the B3-35 scientific pocket calculator (in Russian).
- Elektronika MK-51 Operating Manual (Russian)
The Russian operating manual of the MK-51 scientific: keys and modes, technical data (K757IP1-2 chip, IZhTs2-9/7 LCD, 0.001 W, 64 roubles), worked examples, the circuit diagram and voltage diagrams, and the warranty cards (in Russian). Page images scanned by Surok (ru-hpc.narod.ru), 2009.
- Elektronika MK-52 Operating Manual, Book 1 (Russian)
The first of the two Russian books shipped with the MK-52: operation, the EEPROM, the BRP memory modules and worked examples (in Russian).
- Elektronika MK-52 Operating Manual, Book 2 (Russian)
The second Russian book of the MK-52, mostly programs (in Russian).
- Elektronika MK-52 Schematic
The circuit diagram of the MK-52 programmable calculator (in Russian).
- Elektronika MK-52 Schematic, MEU-4 Sheet
A second MK-52 schematic sheet, marked MEU-4 (in Russian).
- Elektronika MK-52 User Manual (English)
A 63-page English user manual for the MK-52 programmable calculator.
- Elektronika MK-61 Calculator Operating Instructions (English translation by José Mesquita)
A 52-page English translation of the MK-61 operating manual (draft 1.0, October 2014), with the translator's notes on the stack, the power supply and DC-DC converter pins, the D2-10M adapter, test procedures, command codes and example programs.
- Elektronika MK-61 Circuit Diagram (Appendix 5 of the manual)
The factory circuit diagram of the MK-61: converter with winding table and transistor operating points, the six K745 chips and their pin tables, the ILC2-12/8L tube and pull-downs, the keyboard matrix, and oscillograms (in Russian).
- Elektronika MK-61 Operating Manual (Russian)
The 90-page Russian operating manual of the MK-61 programmable calculator: keys, stack, programming, indirect addressing, accuracy and power (in Russian).
- Elektronika MK-85 and MK-85M Operating Manual (Russian)
The 66-page operating manual of the MK-85 and MK-85M BASIC pocket computers, with worked examples (in Russian).
- Elektronika MK-85 Circuit Diagram
The circuit diagram of the MK-85 BASIC pocket computer (in Russian).
- Elektronika MK-90 Operating Manual (Russian)
The 56-page Russian operating manual of the MK-90 BASIC pocket computer (in Russian).
- Elektronika MKSh-2 Operating Manual (Russian)
The operating manual of the MKSh-2 school calculator, which ran from a 42 V AC classroom supply (in Russian).
- Elektronika S3-22 Desk Calculator (Russian Book Excerpt)
Three pages on the Elektronika С3-22 desk calculator from a Soviet book on office computing machines, with its keyboard layout and operations compared with the Iskra-111 (in Russian).
- Epanechnikov and Tsvetkov, Handbook of Applied Programs for Microcalculators (1988, in Russian)
Spravochnik po prikladnym programmam dlya mikrokal'kulyatorov (Finansy i statistika, 1988, 320 pp): a handbook of applied programs for Soviet programmable calculators (in Russian).
- Facit 1114 Calculator: Reverse-Engineered Schematic
Schematic of the Facit 1114 of 1973: Hitachi HD3276 and HD3253, Toshiba TM4352 drivers, Futaba DG10T tubes.
- Flat Panel Multi-Digit Fluorescent Display (SID Digest, 1976)
Ise's paper on its flat nine-digit tube for hand-held calculators: fabrication steps, 2.7 V AC filament, 24 V drive at 1/12 duty, brightness against duty, and a whole-tube power of 39.6 mW.
- Friden 1162 Logic Schematic
The logic-level schematic of the integrated-circuit Friden 1162.
- Friden 130 Electronic Calculator Instruction Manual
The 52-page operator's manual for the EC-130: the keyboard, the four-register stack, ENTER and REPEAT, decimal setting, and worked examples.
- Friden 130 Electronic Calculator Sales Brochure (1964)
The six-page launch brochure: the CRT showing four registers, the 11-key keyboard, "no moving parts".
- Friden Calculator Projects 1961-1968
Friden's internal list of calculator development projects from 1961 to 1968.
- Friden Calculator Projects 1961-1979
Friden's list of calculator projects from 1961 to 1979, including the Hitachi-built EC-111x Nixie line.
- Friden EC-130 Field Service Manual (August 1964)
The 51-page field service manual issued at the EC-130's launch: installation, adjustments, fault finding and parts.
- Friden EC-130 Logic Schematic, Four-Counter (Fall 1964)
The one-sheet logic-level schematic of the four-counter EC-130: every gate and flip-flop, without the power supply, delay-line read/write electronics or CRT drive.
- Friden EC-130 Logic Schematic, Three-Counter (late 1965)
The logic-level schematic of the three-counter EC-130.
- Friden EC-130 Master Design Documentation Computer Printout (1964)
Friden's internal Master Design Documentation printout for the four-counter EC-130, version 1: the machine's logic equations as a computer listing.
- Friden EC-130 Service Manual (September 1965)
The 161-page factory service manual for the four-counter EC-130: theory of operation down to gate level, the delay line and its amplifiers, the counters, every keyboard function as a flow chart, the display circuits (segment, dot and staircase generators, slant and deflection amplifiers, diode matrix), the power supplies including the -2,400 V multiplier, and adjustment procedures.
- Friden EC-130 Three-Counter Service Manual Supplement (December 1965)
The 26-page supplement covering the three-counter EC-130 (serial 8501 on), which drops the B counter.
- Friden EC-130/EC-132 Service Letters #1-#35 (1964-1968)
The factory service letters for the 130 and 132, from July 1964 to June 1968: field changes, fault fixes and production changes, including the three-counter change.
- Friden EC-132 Logic Schematic (June 1965)
The logic-level schematic of the EC-132, including the square-root logic.
- Friden EC-132 Master Design Documentation Computer Printout (June 1965)
Friden's internal Master Design Documentation printout for the four-counter EC-132.
- Friden EC-132 Temporary Service Manual (August 1965)
The interim service manual for the EC-132.
- Friden EC-132 Temporary Service Manual: Square Root Mathematics (1965)
How the EC-132 extracts a square root by subtracting successive odd numbers, for service technicians.
- Friden Final Engineering Report: Magnetostrictive Delay Line (June 1964)
Friden's 48-page engineering report on the EC-130 delay line: the Ni-Span C wire, the transducers, the mounting and the measured performance.
- Friden Report on the Victor 3900 (1965)
A 1965 Friden competitive report concerning the Victor 3900 MOS calculator, held by the Old Calculator Web Museum.
- FunkAmateur, June 1967 (Soemtron 220 announcement, in German)
The June 1967 issue of the East German magazine FunkAmateur, which announced the zero series of the Soemtron 220 Nixie desk calculator from Sömmerda (in German).
- General Instrument Data Catalog (1976)
General Instrument's 1976 data catalogue, including its C-series calculator chips used in many fluorescent pocket calculators.
- Generating Characters (Electronics, 3 January 1958)
The MIT Lincoln Laboratory article on drawing characters on a CRT from sine and cosine waveforms, the method behind the Wyle Scientific's display.
- Geometry of the Prytz Planimeter (Foote)
The mathematics of the hatchet (Prytz) planimeter.
- Haff Planimeters 313, 315 and 317: Instruction Manual
The current manual for Haff's compensating polar planimeters, worded almost exactly like K&E's 1957 manual, with the 200 sq in / 2000 sq cm constant circle.
- Handhabung der Hamann Manus R Rechenmaschine (1953)
The factory operating manual for the Manus R, in German, including the back-transfer lever the R added.
- Handhabung der Hamann Manus Rechenmaschine
The factory operating manual for the Manus (a model D is pictured), in German: the controls, addition, subtraction, multiplication and automatic division, with the numbered control map.
- Hewlett-Packard Journal, June 1972: the HP-35
The Hewlett-Packard Journal of June 1972, introducing the HP-35, with articles on its design, its algorithms and accuracy (Cochran) and its packaging.
- Hewlett-Packard Journal, September 1968: the HP 9100A
The HP Journal issue introducing the 9100A: Osborne on the hardware (CRT display, inductive printed-circuit ROM, core-rope control ROM, core memory), Cochran on the internal programming (number representation, CORDIC-style trigonometry, logarithms), Monnier and Near.
- Historie Diehl: Elektronische Rechner
Pages from Diehl's company history on its electronic calculators, including the Combitron of 1966 (in German).
- Hitachi HD3100 Series PMOS Calculator IC Data Sheets
Data sheets for Hitachi's HD3100-series PMOS chips used in the Friden EC-1114/1115, Casio 121-B and other Japanese Nixie calculators: shift registers, gates, flip-flops and the serial adder.
- HP 9100A Calculator Brochure (1968)
Hewlett-Packard's launch brochure for the 9100A.
- HP 9100A Operating and Programming Manual
The owner's manual for the 9100A (09100-90001): the keyboard, the X, Y, Z display registers, storage registers, programming and magnetic cards.
- HP 9100A Training Manual
Hewlett-Packard's training manual for the 9100A.
- HP 9100A: Trinity College Dublin Computer Collection Catalogue Entry
A detailed catalogue entry on the 9100A: board list, control and program ROMs, microword format, core memory and internal photographs.
- HP 9100A/B Calculator and Peripherals Technical Data (1969)
HP's October 1969 technical data sheet (5952-2119) for the 9100A and 9100B and their peripherals: the 9120A printer, 9125A plotter, 9160A marked-card reader and 9150A display; speeds, numerical format, programming, memory and keyboard.
- HP 9100A/B Interfacing Manual (09100-90031, 1970)
Hewlett-Packard's February 1970 manual for connecting peripherals and instruments to the 9100A and 9100B through their I/O connectors, with a caution that improper signals can severely damage the calculator.
- HP 9100A/B Service Manual (09100-90034, 1971)
Hewlett-Packard's January 1971 service manual for the 9100A and 9100B: pseudo-hardware problems, performance assurance, troubleshooting (verify the problem, check the CRT, troubleshooting tree), assembly locations, the standard and optional supply and deflection-amplifier schematics, waveforms, replaceable parts and backdating. 110-page black-and-white scan.
- HP 9100A/B Service Manual (09100-90034, 1971), Colour Scan
A second, high-resolution colour scan of the January 1971 9100A/B service manual (91 pages), with the covers.
- HP 9100B Microprogram Flowcharts
The algorithmic-state-machine flowcharts of the 9100B's microprogram: the nearest thing to its ROM listing in public.
- HP 9100B Operating and Programming Manual
The owner's manual for the 9100B (09100-90021), with its doubled memory and subroutines.
- HP 9100B Program Library (1969)
HP's library of 9100B programs for science, engineering, statistics and finance.
- HP 9100B Schematics
Factory schematic sheets for the HP 9100B: logic boards, flip-flop boards, side-board expanders, card reader and supplies.
- HP 9100B Schematics, Redrawn by Tony Duell
Tony Duell's hand-drawn schematics of the HP 9100B, traced from a working machine: power supplies, CRT and deflection circuits, logic and the other boards, 182 pages.
- HP 9125A Plotter Service Manual (1970)
The service manual for the 9125A X-Y plotter used with the 9100.
- HP 9160A Marked Card Reader Operating Manual (1969)
The operating manual for the 9160A card reader peripheral of the 9100.
- HP-35 Operating Manual (1972, red dot)
Hewlett-Packard's operating manual for the first-version (red dot) HP-35 (00035-90008).
- HP-35 Operating Manual (1973)
Hewlett-Packard's operating manual for the HP-35, August 1973 edition.
- HP-75 Owner's Manual
Hewlett-Packard's owner's manual for the HP-75C portable computer (00075-90001).
- ILC1-8/8LV Multi-Digit Fluorescent Indicator Datasheet (in Russian)
Label sheet for the Soviet ILC1-8/8LV flat multi-digit fluorescent tube, a relative of the calculator ILC1-8/8L: 5 V filament, 35-50 V segment and 30-40 V grid pulses, -7 V grid cut-off (in Russian).
- IME 26 Instruction Manual
The instruction manual for the IME 26 commercial calculator: keyboard, registers, basic operations, constants, chain calculations and worked commercial examples.
- IME 84 Calculator: Reverse-Engineered Schematic
A 26-page schematic of the IME 84 of 1964: germanium DTL, core memory, decade counters and the 16-digit multiplexed Nixie display, with a board list (408 transistors, 1,045 diodes).
- IME 84 Calculator: Theory of Operation
A 33-page theory of operation of the IME 84: the 20 kHz clock and digit cycle, core read and write, decade-counter arithmetic, the procedures for each key, and notes on replacing germanium parts (BAT46, 2N3906, MPSA92).
- IME 86S Calculator: Reverse-Engineered Schematic
A 27-page schematic of the IME 86S, the IME 84's successor: discrete germanium logic, core memory and Nixie display.
- IME 86S Calculator: Theory of Operation
A 34-page theory of operation of the IME 86S, written from the reverse-engineered schematic.
- IN-14, IN-17 and Related Nixie Tubes: Reference Table (in Russian)
A reference table of Soviet gas-discharge indicator tubes, including the IN-14 used in the Iskra desk calculators: striking and maintaining voltages, supply and brightness (in Russian).
- Ise Electronics Itron DG-12C Numerical Indicator Tube Datasheet (June 1968)
Datasheet of the single-digit DG-12C fluorescent tube: filament 0.85 V at 95 mA, segments 25 V and grid 20 V typical, grid cut-off -4 V, segment cut-off 0 V, 80 foot-lamberts, dimensions and pinout.
- Ise Electronics Itron DG-19 Numerical Indicator Tube Datasheet (February 1968)
Datasheet of the single-digit DG-19 fluorescent tube: filament 1.6 V at 95 mA, segments 25 V and grid 20 V typical, ratings and dimensions.
- Ise Electronics Itron DG12B Datasheet
Datasheet of the DG12B, the first mass-produced vacuum-fluorescent tube, used in the Sharp CS-16A: ratings, characteristics and outline.
- Ise Electronics: Development and Commercialization of the VFD (case study, in Japanese)
A business-history case study of Ise Electronics and the vacuum-fluorescent display: Tadashi Nakamura, Sharp, the Burroughs Nixie royalties, production growth and licensing (in Japanese).
- Iskra 110 Operating Manual (Russian)
The operating manual of the Iskra 110 electronic keyboard computing machine (in Russian).
- Iskra 111 Operating Manual (Russian)
The operating manual of the Iskra 111 desk calculator, from the Orel Plant of Control Computing Machines, Ministry of Instrument Making (in Russian).
- IV-4 (IV-4) Fluorescent Indicator Tube Datasheet, Sheet A (in Russian)
Datasheet of the Soviet IV-4 eighteen-segment fluorescent tube: filament 2.2-2.9 V at 50 mA, 25-27 V static and 50-70 V pulsed drive (in Russian).
- IV-4 Fluorescent Indicator Tube Datasheet, Sheet B (in Russian)
Second sheet of the Soviet IV-4 fluorescent tube datasheet (in Russian).
- Know Thy Foe: A New Contender (HP-41C and Sharp PC-1211)
Valentin Albillo's period comparison of the HP-41C programmable calculator and the Sharp PC-1211 pocket computer.
- Learn BASIC: A Guide to Programming the TI Compact Computer 40
David Thomas's guide to programming the TI CC-40 in BASIC.
- Lightning Calculator: Collection Record (FAU ISER)
The Erlangen computer-science collection's record of a Grand Rapids Lightning D-3 on its wooden base: 7 digits, 33 × 9 × 5 cm, 720 g with the stand.
- Lloyd's 310 Calculator: Reverse-Engineered Schematic
Schematic of the Lloyd's 310 pocket calculator with a nine-digit fluorescent tube.
- Lloyd's Accumatic 55 Calculator: Reverse-Engineered Schematic
Schematic of the Lloyd's Accumatic 55 (also labelled EH-8715) pocket calculator with a nine-digit fluorescent tube.
- LogicData TA-9 Calculator: Reverse-Engineered Schematic
Schematic of the LogicData TA-9 pocket calculator of 1972 with a fluorescent display.
- Mechanical Integrators, Including the Various Forms of Planimeters (Shaw, 1886)
Hele Shaw's survey of planimeters and integrators of every kind known in 1886, with their theory.
- Microchip HV5812 20-Channel High-Voltage VFD Driver Datasheet
Datasheet of the HV5812 serial-input 20-output driver for vacuum-fluorescent displays, with outputs to 80 V.
- Miida MC1214 Calculator: Reverse-Engineered Schematic
Schematic of the Miida MC1214 desk calculator of 1972 with an Ise DP127F twelve-digit fluorescent tube.
- Miida MC800 Calculator: Reverse-Engineered Schematic
Schematic of the Miida MC800 of 1971: Omron ALPHA1-3 chip set, discrete A628A PNP drivers to -58 V, NEC LD8027 single-digit tubes, lamps for minus and overflow, inter-digit blanking.
- Miida MC840 Calculator: Reverse-Engineered Schematic
Schematic of the Miida MC840 desk calculator of 1972 with an Ise DP82A eight-digit fluorescent tube.
- Modern Electronic Package for the Wang 300 Series Consoles: Manual
Bob Alexander's manual for his PIC32 board that brings a Wang 300 keyboard console to life without the original electronic package: installation, keyboard and Nixie testing, cathode poisoning, the Wang emulation, a GPS clock and an RPN calculator.
- Monroe 920 Service Manual
The 116-page service manual for the Monroe 920 electronic calculator.
- Monroe 925 Calculator: Reverse-Engineered Schematic
A 17-page schematic of the Monroe 925 of 1970, with delay-line memory and multiplexed JRC B-5755 Nixies.
- Monroe 925 Logic and Timing Manual
Monroe's logic and timing manual for the 925 Nixie calculator.
- Mostek Calculator Chips: Advertisement
A Mostek advertisement for its single-chip calculator circuits.
- Mostek Integrated Circuit Guide (1974)
Mostek's 1974 catalogue of MOS integrated circuits, including its MK50xx calculator chips, descendants of the MK6010 made for Busicom.
- National Semiconductor AN-440: Driving Vacuum Fluorescent Displays
Application note on VF display drive: the drive-voltage equation, filament bias by Zener on the centre tap, the 'rolling' beat between refresh and filament frequency, and the MM58341/MM58348 drivers.
- National Semiconductor MOS Integrated Circuits (1974)
National Semiconductor's 1974 MOS data book, including its MM57xx calculator chips.
- Nikkan Kogyo Shimbun, 17 July 1967: Character Display at About 25 Volts (with English translation)
A Japanese trade-paper report that Ise Electronics had developed the Digitron, a numeric display tube working at about 25 volts, with an English translation.
- Noritake Itron Application Note APN201: Cut-off and Filament Bias
One page of Noritake's VFD application notes: luminance curves against anode and grid voltage, cut-off voltages, and why the filament centre tap carries the bias.
- North American Rockwell: MOS LSI Standard Building-Block Circuits for Calculators (January 1971)
Rockwell's 1971 catalogue of MOS-LSI building-block circuits for calculators, from the period of the four-chip sets in the Sharp QT-8D and EL-8.
- Ochkov and Khmelyuk, From the Microcalculator to the Personal Computer (1990, in Russian)
Ot mikrokal'kulyatora k personal'nomu komp'yuteru (MEI, 1990, 150,000 copies): a key source on the undocumented behaviour of the B3-34 and MK-61 ('eggogology') (in Russian).
- Olympia CD401A Calculator: Reverse-Engineered Schematic
Schematic of the Olympia CD401A of 1974: TI TMS0206 and TMS0318, HD3281P decoder, TM4312 and TM4352 driver arrays, Futaba 13-MR-01 tube, converter supply with 1.6 V DC filament at -47 V.
- Olympia RAE 4/15-2: Collection Data Sheet
The FAU Erlangen collection record for an Olympia RAE 4/15-2 electronic calculator of 1964, with 15 Nixie tubes.
- Operating the Hamann Manus Calculator (English translation)
An English translation of the DeTeWe Manus manual by Knut Faegri Jr., with Steven L. Carter, Heinz Schneemann and Christian Hamann.
- Panasonic JE-850 Instruction Manual
The 16-page manual of the Panasonic JE-850 MOS-LSI desk calculator.
- Personal Computer World, August 1987: Psion Organiser II Benchtest
Personal Computer World's review of the Psion Organiser II.
- Pocket Computer Programming Made Easy
Jim Cole's BASIC tutorial for the TRS-80 Pocket Computer and Sharp PC-1211, with material for the PC-2 and PC-1500 (ARCsoft Publishers).
- Position Determination with Loran-C Triplets Using the HP-75C, the Sharp PC-1500 (TRS-80 PC-2) or the TRS-80 Model 100
A Naval Postgraduate School report (NPS55-83-023, September 1983) by Rex H. Shudde with programs for Loran-C navigation fixes on the HP-75C, the Sharp PC-1500 and the TRS-80 Model 100.
- Problem-Solving on the TRS-80 Pocket Computer
A Wiley self-teaching guide to programming the TRS-80 Pocket Computer.
- Pukhov, The Real Truth: English Translation with the Lunolet-1 Listing
A seven-page English translation of Pukhov's 1985 story, with the full Lunolet-1 program listing and the game's worked setup (machine-assisted translation).
- Radio Shack TRS-80 Pocket Computer Solutions to Composite Materials Formulas
A US Air Force Materials Laboratory report (AFWAL-TR-81-4074, August 1981) by Won J. Park of Universal Energy Systems: composite-materials formulas programmed on the TRS-80 Pocket Computer.
- Reparaturanleitung Hamann Automat S
The factory repair manual for the Automat S, in German, 29 pages: the switching-latch drum, adjustments, a fault table and service figures. The drum is the same mechanism as the Manus's, so it is the nearest thing to a Manus repair manual.
- Ricomac 1216 Calculator: Reverse-Engineered Schematic
Schematic of the Ricomac 1216 of 1974: Hitachi HD3574 and HD3256, HD3233 and TM4352 driver arrays, Futaba DG10W1 tubes with an SP10D5M sign tube.
- Royal Digital V Calculator: Reverse-Engineered Schematic
Schematic of the Royal Digital V pocket calculator of 1972 with an eight-digit fluorescent tube.
- Russian Nixie Tube Data Sheets (compilation)
A compilation of data sheets for Soviet IN-series Nixie tubes, from Dieter Waechter's tube archive.
- Sanyo ICC-0081 Logic Circuit Diagram
A 26-page Sanyo service document for the ICC-0081: block diagram, register and sequence charts, key-signal schematic and gate equations for its four LSI chips.
- Sharp CE-122 Brochure
Sharp's sales brochure for the CE-122 printer and cassette interface.
- Sharp CE-122 Printer/Cassette Interface Instruction Manual
Sharp's instruction manual for the CE-122 printer and cassette interface for the PC-1211, the original of Radio Shack's 26-3505.
- Sharp Compet 17 Calculator: Reverse-Engineered Schematic
A 17-page schematic of the Sharp Compet 17 of 1968: MSI MOS logic and multiplexed Hitachi CD-81 Nixies.
- Sharp Compet ELSI-814 Instruction Manual
The 50-page multilingual manual of the Sharp ELSI-814 desk calculator.
- Sharp EL-5001 Instruction Manual
The 28-page manual of the Sharp EL-5001 scientific desk calculator: statistics, quadratic equations, integration, complex numbers and vectors.
- Sharp EL-8131 Calculator: Reverse-Engineered Schematic
Schematic of the Sharp EL-8131 ELSI MATE of 1978 with a nine-digit Futaba fluorescent tube.
- Sharp ELSI MATE EL-8131 Instruction Manual
The 24-page manual of the Sharp EL-8131 pocket calculator with a Futaba fluorescent tube.
- Sharp ELSI-804 Calculator: Reverse-Engineered Schematic
Schematic of the Sharp ELSI-804 desk calculator of c. 1973: Hitachi HD3276 and HD3253, Toshiba TD2007 clock at 46.1 kHz, TM4356 driver arrays, nine Futaba DG10Q1 or NEC LD8051 tubes, -44 V and -49 V display rails, filaments in series.
- Sharp Micro Compet QT-8D Instruction Manual
The 20-page instruction book of the QT-8D: keys, the combined += and -= keys, worked examples of every operation, decimal point call-back, overflow, and specifications (78 kHz clock, four ELSI chips).
- Sharp PC-1210 and PC-1211 Flyer (Japanese, first version)
A Japanese Sharp flyer for the PC-1210 and PC-1211 pocket computers.
- Sharp PC-1210 and PC-1211 Flyer (Japanese, second version)
A second version of Sharp's Japanese flyer for the PC-1210 and PC-1211.
- Sharp PC-1211 and CE-121 Service Manual
Sharp's service manual for the PC-1211 pocket computer (Radio Shack's TRS-80 Pocket Computer) and the CE-121 cassette interface: specifications, block diagram, RAM maps, display and power circuits, LSI signal descriptions, disassembly, cassette format, check program, circuit diagrams and parts lists.
- Sharp PC-1211 Applications Manual
Sharp's 314-page book of application programs for the PC-1211: equations, matrices, statistics, coordinates and more.
- Sharp PC-1211 Beginner's Textbook for BASIC
Sharp's 52-page introduction to BASIC programming on the PC-1211.
- Sharp PC-1211 Brochure
Sharp's sales brochure for the PC-1211 pocket computer.
- Sharp PC-1211 Instruction Manual
Sharp's own instruction manual for the PC-1211 pocket computer, 106 pages.
- Sharp PC-1500 Instruction Manual
Sharp's instruction manual for the PC-1500 pocket computer (English).
- Sharp PC-1500 Technical Reference Manual
Sharp's technical reference for the PC-1500: the LH5801 processor, machine code and the system.
- Sharp PC-1500A Instruction Manual
Sharp's instruction manual for the PC-1500A.
- Sharp PC-E500 Service Manual
Sharp's service manual for the PC-E500 pocket computer.
- Sharp PC-G850V(S) User Manual (English translation)
An English translation of the manual for Sharp's PC-G850V and PC-G850VS, the last pocket computers.
- Sharp Pocket Computer Katalog (German)
Sharp's German catalogue of its pocket computers and accessories.
- Sinclair Scientific Instructions
The instruction booklet for the Sinclair Scientific calculator.
- Singer Friden 1115 Electronic Calculator Service Manual (December 1969)
The service manual for the EC-1115: specifications, key functions, worked calculating methods, the Hitachi HD3100 chips, register operation, the anode charge-pump and cathode control circuits of the 12-tube Nixie display, power supply, troubleshooting and flow charts.
- Singer Friden EC-1113 Service Manual (June 1969)
The 132-page service manual for the Hitachi-built EC-1113, with 108 HD700 PMOS chips and 12 Hitachi Nixies; some pages missing.
- Sony SOBAX 2500 Calculator: Reverse-Engineered Schematic
A 27-page schematic of the programmable Sony SOBAX 2500 of 1969-70: the 362 cm longitudinal delay line, the phase-locked master clock, Sony 500-series logic and the multiplexed Hitachi CD-81 Nixie display.
- Sony SOBAX 2500 Calculator: Schematic Appendix
Eleven pages of supporting drawings for the Sony 2500 schematic: timing, register maps and state diagrams.
- Sony SOBAX 2500 Calculator: Theory of Operation
A 52-page theory of operation: the delay line time-multiplexed into 16 channels, the PLL clock locked to the line, the 1-2-4-2 serial arithmetic, programming, the display latch, zero blanking and thousands separators.
- Tandy Model PC-4 Pocket Computer Programming Guide
The programming guide for the Tandy PC-4, Radio Shack's version of the Casio PB-100.
- TEAL IME 41 Calculator: Reverse-Engineered Schematic
Nineteen-page schematic of the IME 41 desk calculator of 1970, built on MSI MOS logic with individual fluorescent tubes.
- TEAL Royal Digital I Calculator: Reverse-Engineered Schematic
Eighteen-page schematic of the Royal Digital I desk calculator of 1971: 29 NEC and Mitsubishi MOS chips on -24 V, ten Ise DG-12C tubes with filaments in series, grid blanking transistor.
- Tekhnika — Molodezhi, 1985 No. 6, with M. Pukhov's 'The Real Truth' and Lunolet-1 (in Russian)
The full 68-page issue of Tekhnika — Molodezhi that printed Mikhail Pukhov's story Istinnaya pravda with the Lunolet-1 lunar-landing program for the B3-34, and launched the Electronic Games Club (in Russian).
- Texas Instruments TI-1025 Calculator: Reverse-Engineered Schematic
Schematic of the TI-1025 of 1979: TMC0923 chip, Itron FG85C1 tube, a 61.4 kHz charge pump to -22 V from a 9 V battery, and a 7 V 1.5 kHz square-wave filament supply.
- The Curta, a Technical Marvel
Herbert Bruderer's 2022 article on Curt Herzstark and the Curta, its manufacture in Liechtenstein, and what newly found patent documents and design drawings show about the Multiple Curta, a parallel calculator.
- The Lightning Calculator: Bonham, Hook and Pangborn
Otnes's history of the Lightning and its makers, from Grand Rapids and Los Angeles city directories, with photographs and X-rays of the machines. Journal of the Oughtred Society 11:1 (Spring 2002), pp. 53–58.
- The Polar Planimeter and Its Use in Engineering Calculations (Wheatley, 1903)
K&E's book on the polar planimeter: its theory, the zero circle, and its use for indicator diagrams, earthwork, reservoirs and other engineering calculations.
- The Polar Planimeter of Jakob Amsler (van der Salm)
A history and vector-analytic treatment of Amsler's polar planimeter and its precursors.
- TI SR-10 Owner's Manual
Texas Instruments' owner's manual for the SR-10, its first slide-rule calculator.
- TI SR-50 Owner's Manual
Texas Instruments' owner's manual for the SR-50 scientific calculator.
- TI SR-51 Owner's Manual
Texas Instruments' owner's manual for the SR-51 and SR-51A.
- TI TMS 1000 Series Data Manual (December 1976)
TI's data manual for the TMS1000 microcomputer family, including the high-voltage TMS1070 and TMS1270 that drive fluorescent displays directly, with a strobed VFD interconnect diagram.
- TI TMS0117 Arithmetic Processor Datasheet
Datasheet of the TMS0117, a member of TI's TMS0100 single-chip calculator family: pinout, timing and functions.
- TI-30 Owner's Manual (1976)
Texas Instruments' owner's manual for the original LED TI-30 of 1976.
- TI-30 SLR Owner's Manual
Texas Instruments' owner's manual for the TI-30 SLR.
- TI-30-II Owner's Manual
Texas Instruments' owner's manual for the TI-30-II.
- TI-30X IIS Reference Guidebook
Texas Instruments' reference guide for the TI-30X IIS two-line scientific calculator.
- TI-30X IIS Teacher Guide
Texas Instruments' teacher guide and activities for the TI-30X IIS.
- TI-30X MultiView Reference Card
Texas Instruments' quick-reference card for the TI-30X MultiView calculators.
- TI-30X Pro MultiView Guidebook
Texas Instruments' guidebook for the TI-30X Pro MultiView, the European twin of the TI-36X Pro.
- TI-30XS MultiView / TI-30XB MultiView Guidebook
Texas Instruments' guidebook for the TI-30XS MultiView, its first non-graphing calculator with a dot-matrix display.
- TI-30XS MultiView Teacher Guide
Texas Instruments' teacher guide for the TI-30XS MultiView, with classroom activities.
- TI-36X Pro Calculator Guidebook
Texas Instruments' guidebook for the TI-36X Pro: modes, MathPrint, memories, calculus, statistics and distributions, tables, matrices, vectors, solvers, number bases, constants, conversions, complex numbers and battery replacement, with worked examples.
- TI-36X Solar Guidebook
Texas Instruments' guidebook for the TI-36X Solar engineering calculator, the TI-36X Pro's predecessor.
- TI-55 Owner's Manual
Texas Instruments' owner's manual for the TI-55 programmable scientific.
- Tom Osborne's Story: the Green Machine and the HP 9100
Osborne's own account, written to Barney Oliver, of designing the Green Machine prototype and the HP 9100A.
- Toshiba BC-0801B Instruction Manual
The 10-page manual of the Toshiba BC-0801B desk calculator.
- Toshiba BC-0802 Calculator: Reverse-Engineered Schematic
Schematic of the Toshiba BC-0802 desk calculator of 1972 with NEC LD8035 or Toshiba fluorescent tubes.
- Toshiba BC-1212 Calculator: Reverse-Engineered Schematic
A 17-page schematic with state diagram of the Toshiba BC-1212 of 1970: MSI MOS logic and multiplexed NEC LD-955A Nixies, including the under-rated 0.022 uF digit-driver capacitors.
- Tractrices, Bicycle Tire Tracks, Hatchet Planimeters, and a 100-year-old Conjecture (2013)
American Mathematical Monthly 120 (2013): the hatchet planimeter and its connection with bicycle tracks.
- Trokhimenko and Lyubich, Microcalculator, Your Move! (1985, in Russian)
Mikrokalkulyator, vash khod! (Radio i svyaz', 1985, 224 pp, 100,000 copies): programming methods, games and models of moving vehicles for programmable calculators (in Russian).
- Trokhimenko et al., Programmable Microcalculators: Design and Use (1990, in Russian)
Programmiruemye mikrokalkulyatory: ustroistvo i pol'zovanie (Radio i svyaz', 1990, 272 pp): the main published account of the hardware and software of the B3-34 and MK-61 family (in Russian).
- TRS-80 PC-1 Pocket Computer and Cassette Interface Service Manual
Radio Shack's service manual for the TRS-80 Pocket Computer (26-3501) and Cassette Interface (26-3503), with Radio Shack part numbers: specifications, block diagram, signals, disassembly, cassette tests, check program, schematics and parts lists.
- TRS-80 PC-2 Operations Manual
The operations manual for the TRS-80 PC-2, Radio Shack's version of the Sharp PC-1500.
- TRS-80 PC-2 Printer/Cassette Interface Manual
The manual for the PC-2's printer, plotter and cassette interface (26-3605), the Sharp CE-150.
- TRS-80 Pocket Computer Engineering Math II
The manual for Radio Shack's Engineering Math II software for the Pocket Computer.
- TRS-80 Pocket Computer Games II Instruction Manual (26-3523)
The instructions for Radio Shack's Games II cassette for the Pocket Computer.
- TRS-80 Pocket Computer Games Instruction Manual (26-3515)
The instructions for Radio Shack's Games cassette for the Pocket Computer.
- TRS-80 Pocket Computer Owner's Manual
The 126-page owner's manual for the TRS-80 Pocket Computer (26-3501): manual calculation, programming in BASIC, the reservable keys, cassette commands, error codes, specifications and battery replacement.
- TRS-80 Pocket Computer Printer/Cassette Interface Manual (26-3505)
The manual for the 26-3505 Printer/Cassette Interface: docking, paper and ribbon, the Ni-Cd battery, the POWER, PRINT and REMOTE switches, printing with LIST and PRINT, and specifications.
- TRS-80 Pocket Computer Programs
Jim Cole's book of fifty ready-to-run programs in Pocket BASIC for business, education and fun, sold by Radio Shack (cat. no. 62-2066); also published by Artsoft.
- TRS-80 Pocket Computer Reference Card
The quick-reference card for the TRS-80 Pocket Computer: commands, statements, functions and error codes.
- TRS-80 Pocket Computer Statistical Analysis (26-3522)
The manual for Radio Shack's Statistical Analysis software for the Pocket Computer.
- Unisonic 790R Instruction Manual
The 16-page manual of the Unisonic 790R pocket calculator, with NiCd, dry-cell and adapter operation.
- US Design Patent D163,135: Pocket Adding Apparatus (K. R. Pangburn)
Design patent of 1 May 1951 for Pangburn's pocket adder, whose mechanism is virtually identical to the Lightning's.
- US Design Patent D163,136: Pocket Adding Apparatus Unit (K. R. Pangburn)
The companion design patent of 1 May 1951 for Pangburn's pocket adder.
- US Patent 1,011,617: Calculating-Machine (C. Hamann, the proportional lever)
Hamann's proportional lever for the Mercedes-Euklid, filed 28 June 1910 and granted 12 December 1911 (DE 209,817).
- US Patent 1,410,507: Calculating Machine (W. T. Ray)
Ray's stylus calculating machine, granted 21 March 1922, one of the dial adders related to the Lightning.
- US Patent 1,574,249: Adding Machine (R. W. Hook, the Lightning)
Hook's patent for the Lightning Adding Machine, filed 17 February 1921 and granted 23 February 1926: the actuators, numeral wheels, long carry tooth and weighted pawls of the stylus dial adder. The Dial-Adders theory volume uses its part numbers.
- US Patent 1,764,915: Calculating Apparatus (A. E. Vethe, the Addometer)
Vethe's Addometer patent, filed 10 September 1928 and granted 17 June 1930.
- US Patent 1,788,192: Computing Machine (C. Hamann, the Manus switching latch)
Hamann's switching-latch calculator with automatic division, filed 17 December 1925 and granted 6 January 1931; the US twin of DE 432,435. The Manus theory volume uses its part numbers.
- US Patent 1,829,379: Computing Machine (A. E. Vethe, the Addometer)
Vethe's computing-machine patent, filed in Oslo on 20 October 1926 and granted 27 October 1931.
- US Patent 1,940,069: Calculating Machine (J. H. Bair)
The Bair / Bair-Fulton adder, granted 19 December 1933: "essentially a Kummer" with an assisted manual carry, a borderline member of the stylus dial-adder type.
- US Patent 1,968,201: Calculating Machine (C. Hamann, the Automat)
Hamann's electric switching-latch machine with automatic multiplication, granted 31 July 1934.
- US Patent 2,450,668: Calculator (E. G. Kesling, the Kes-Add)
Kesling's pocket dial adder, filed 22 May 1944 and granted 5 October 1948.
- US Patent 2,797,047: Calculator (O. Lehre, the Dial-A-Matic)
Lehre's Dial-A-Matic, granted 25 June 1957.
- US Patent 2,874,320: Indicating Device (H. J. Hampel, Burroughs Nixie)
The Burroughs stacked-cathode indicator tube, filed 13 December 1955 and granted 17 February 1959: photo-etched character cathodes, offset stacking for wide viewing, insulating light-absorbing rear coatings.
- US Patent 2,935,257: Releasable Restraining Device for Rotatable Parts of Calculators (E. G. Kesling)
Kesling's later patent for his pocket dial adder, filed 26 January 1955 and granted 3 May 1960.
- US Patent 3,280,315: Key Controlled Decimal Electronic Calculating Machine (N. Kitz, Bell Punch, ANITA)
Kitz's ANITA patent, filed 29 December 1961 (priority 1957) and granted 18 October 1966: decade counting devices, nines-complement subtraction, multiplication by repeated addition and shifting, division by repeated subtraction, and an early brush-scanned version with numeral wheels.
- US Patent 3,305,843: Display Apparatus (T. J. Scuitto, Wyle Laboratories)
The Wyle Scientific display, filed 16 December 1963 and granted 21 February 1967: digits drawn from gated sine and cosine arcs, timed from a cyclic memory.
- US Patent 3,388,384: Zero Suppression Circuit (General Micro-electronics, Victor 3900)
The Victor 3900's leading-zero suppression for its CRT display.
- US Patent 3,402,285: Calculating Apparatus (An Wang, logarithms)
Wang's logarithm method, filed 22 September 1964 and granted 17 September 1968: stored logs of 10, 2, 0.9, 1.01, 0.999 and 1.0001, factors of the form 1 +/- 10^-n applied by shift and add, with worked tables for ln 2.10 and the antilog of 4.23845.
- US Patent 3,430,095: Cathode Ray Tube Beam Positioning System Employing Composite Signals (Friden)
The SRI-developed Friden display, filed 8 July 1965 and granted 25 February 1969: staircase generators for position, a segment counter, weighted stroke origins and an oscillator sweep for the strokes.
- US Patent 3,453,601: Two Speed Arithmetic Calculator (Bogert and Miner, Victor 3900)
The Victor 3900's MOS calculator, running at 330 kHz to compute and 60 kHz to display, with stroke-drawn figure-8 digits.
- US Patent 3,454,785: Shift Register Employing Insulated Gate Field Effect Transistors (Norman, GME)
General Micro-electronics' dynamic MOS shift register, the memory of the Victor 3900.
- US Patent 3,508,101: Character Indicating Electron Tube (M. Tanji, Ise Electronics)
The basic vacuum-fluorescent display patent, filed 19 October 1967 (Japanese priority 27 March 1967) and granted 21 April 1970: fine oxide cathode, mesh grid, phosphor-coated segment anodes viewed through the cathode, about 0.8 V on the filament and +25 V on grid and anodes.
- US Patent 3,518,629: Recirculating Memory Timing (S. P. Frankel, Computron / SCM Cogito)
Frankel's recirculating-memory timing, from the design line that became the SCM Cogito 240.
- US Patent 3,523,282: Calculator (R. A. Ragen, Friden)
A second Ragen calculator patent, filed 24 September 1964 and granted 4 August 1970.
- US Patent 3,526,760: Square Root (R. A. Ragen, Friden EC-132)
The EC-132's square-root method by subtraction of successive odd numbers, filed 1 April 1966 and granted 1 September 1970.
- US Patent 3,546,676: Calculator (R. A. Ragen, Friden)
Ragen's master patent for the Friden electronic calculator, filed 29 October 1963 and granted 8 December 1970: recirculating memory, single-digit counters, the CRT display. Hundreds of drawing sheets.
- US Patent 3,566,160: Simplified Race-Preventing Flip-Flop (T. E. Osborne, HP)
The J-K flip-flop with selectable noise immunity used throughout the HP 9100.
- US Patent 3,588,873: Information Display Apparatus (Osborne, Magleby, Lukes, HP)
The HP 9100 display, filed 12 November 1968 and granted 28 June 1971: figure-8 characters from E- and I-shaped sweeps, narrow-character centring, grouping in threes, mains-locked refresh.
- US Patent 3,623,156: Calculator Employing Multiple Registers and Feedback Paths (T. E. Osborne, HP)
Osborne's calculator architecture patent behind the 9100: power gating, subroutine control and the integrated CRT pattern.
- US Patent 3,634,666: Electronic Desk Top Calculator Having a Delay Line and Automatic Decimal Alignment (Friden)
A division of Ragen's master patent: the delay-line organisation, register roles and automatic decimal alignment.
- US Patent 3,654,612: Display System Using a Cathode-Ray Tube (Takachiho Koheki, Descal)
The Descal ASI-500 display: slope and step sweeps with a ROM blanking the unused parts of each digit.
- US Patent 3,723,789: Flat Composite Fluorescent Display Tube (M. Tanji, Ise Electronics)
Ise's multi-digit fluorescent tube patent, filed 8 December 1970 (Japanese priority 13 December 1969) and granted 27 March 1973: several digits in one envelope with common segment wiring and a grid per digit.
- US Patent 3,778,778: Calculator with Self-Synchronous Recirculating Memory (Friden)
The delay-line timing of the Friden calculators: a gated clock resynchronised by a sync pulse on every pass, the 16-column, 6-register, 16-bit data train, and pulse-count digits.
- US Patent 3,786,295: Anode Substrates for Multi-Digit Fluorescent Display Tubes (Ise Electronics)
Ise's patent on the thick-film printed anode plate of the flat multi-digit tube, filed 20 October 1972 and granted 15 January 1974.
- US Patent 3,819,921: Miniature Electronic Calculator (Kilby, Merryman and Van Tassel)
Texas Instruments' patent on the hand-held electronic calculator, the Cal-Tech: priority 13 May 1971, granted 25 June 1974.
- US Patent 4,074,351: Variable Function Programmed Calculator (Boone and Cochran)
Texas Instruments' patent on a single-chip programmed calculator: filed 24 February 1977, granted 14 February 1978.
- US Patent 4,081,716: Fluorescent Display Elements (S. Uemura, Ise Electronics)
Ise's patent on fluorescent display elements, granted 28 March 1978, cited by the IEEE Milestone proposal as the basis of the active VFD.
- US Patent 414,959: Adding Machine (C. H. Webb, improved)
Webb's improved adder, filed 28 April 1888 and granted 12 November 1889.
- US Patent 689,255: Adding-Machine (J. J. Walsh, the Calcumeter)
Walsh's Calcumeter, filed 16 January 1901 and granted 17 December 1901: a straight row of identical stylus dials with a latch carry, the first commercial success of the type.
- US Patent 75,322: Improvement in Adding-Machines (C. H. Webb)
Webb's adder of 10 March 1868: two concentric stylus wheels, 00 to 99 and hundreds. The first dial adder to sell in quantity in America.
- US Patent 832,666: Calculating-Machine (C. Hamann, the Gauss)
Hamann's round calculating machine, the Gauss, filed 28 March 1905 and granted 9 October 1906 (DE 194,527).
- US Patent 845,747: Calculating-Machine (W. R. Bonham)
Bonham's stylus dial adder, filed 20 November 1905 and granted 5 March 1907: a row of dials with two reversed rings of numerals for adding and subtracting. The Lightning's direct ancestor.
- US Patent 897,688: Resetting Device for Adding-Machines (J. J. Walsh)
The Calcumeter's reset wheel, filed 29 November 1907 and granted 1 September 1908.
- US Patent 908,731: Calculating-Machine (W. R. Bonham, carrier-disk carry)
Bonham's second patent, filed 6 April 1905 and granted 5 January 1909: the carrier-disk tens carry between the stylus dials.
- Using and Programming the Psion Organiser II
A book on using and programming the Psion Organiser II in OPL.
- Vacuum Fluorescent Displays: From Single Digits to Colour TV (Displays, 1983)
Ise's own account of the VFD: construction of filament, grid, phosphor and envelope, the oxide cathode at 650 C, ZnO:Zn response times, and the brightness curves against filament voltage, anode and grid voltage and duty, from single digits to colour panels.
- VF Display Fundamentals (Allegro MicroSystems application note)
How a vacuum-fluorescent display is driven: static and multiplexed drive, filament supply and bias, blanking and capacitive loads, and VF driver ICs.
- Victor Medalist 204 Calculator: Reverse-Engineered Schematic
Schematic of the Victor Medalist 204 of 1976: Rockwell A4540CB single chip, discrete PNP drivers to -55 V, Futaba 13-MT-26 tube with 4.6 V DC filament, 136 Hz scan.
- Wang 300 Series Electronic Calculator Instruction Manual, Volume 1 (1968)
The 84-page operator's manual for the Wang 300, 310, 320, 360 and 362: installation, the work register, two adders and log register, every key with worked examples, accumulator switches, storage registers, trigonometric keyboards, card programming and the item counter.
- Wang 320K Keyboard/Display Unit: Reverse-Engineered Schematic
A 3-page schematic of the Wang 320K keyboard and display unit of the Wang 300 series: the key encoder, the diode-matrix Nixie decoder, cathode and anode drivers on +250 V, and the connector pinouts to the electronic package.
- Wang 500 Schematic
Factory schematics of the Wang 500 programmable calculator.
- Wang 700 A/B Manual
The 96-page manual for the programmable Wang 700A and 700B calculators.
- Wang 720A/B Reference Manual (1970)
The reference manual for the programmable Wang 720A and 720B, with Nixie display.
- Wang Laboratories Catalog and Price List (November 1968)
Wang's product catalogue and price list of November 1968: the 300 series packages and keyboards, programmers, the 700-series precursors, peripherals and prices.
- Wang LOCI Service Manual
The factory service manual for the Wang LOCI logarithmic calculators: logic, timing, the core store, power supply and maintenance.
- Wang LOCI-2 Reference Manual (December 1966)
The 108-page LOCI-2 reference manual: the W, A and L registers, logarithmic multiplication and division, storage registers, the program counter and card programs, decisions, loops, subroutines, Newton's method, and diagnostics.
- Wyle Scientific Instruction Manual (1964)
The 20-page operating manual for the Wyle WS-01/WS-02 Scientific: registers, functions, and the optional PC-01 punched-card reader.
- Your CURTA Calculator
The Curta operating instructions for Models I and II: handling, the four operations, and care. This is a retyped edition of Contina's printed manual, transcribed by Rick Furr in 1997 and reformatted as a PDF by Daniel Ford in 2005, so its page layout is not the original's.
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