DOCSLIB.ORG

Calculator from Wikipedia, the Free Encyclopedia

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Calculator from Wikipedia, the Free Encyclopedia Calculator From Wikipedia, the free encyclopedia An electronic calculator is a small, portable electronic device used to perform both basic operations of arithmetic and complex mathematical operations. The first solid state electronic calculator was created in the 1960s, building on the extensive history of tools such as the abacus, developed around 2000 BC, and the mechanical calculator, developed in the 17th century. It was developed in parallel with the analog computers of the day. The pocket sized devices became available in the 1970s, especially after the first microprocessor developed by Intel for the Japanese calculator company Busicom. They later became commonly used within the Oil and Gas industry. An electronic pocket calculator with a LCD seven­ Modern electronic calculators vary from cheap, give­away, credit­card­ segment display, that can sized models to sturdy desktop models with built­in printers. They perform arithmetic became popular in the mid­1970s as integrated circuits made their size operations. and cost small. By the end of that decade, calculator prices had reduced to a point where a basic calculator was affordable to most and they became common in schools. Computer operating systems as far back as early Unix have included interactive calculator programs such as dc and hoc, and calculator functions are included in almost all PDA­type devices (save a few dedicated address book and dictionary devices). In addition to general purpose calculators, there are those designed for specific markets; for example, there are scientific calculators which include trigonometric and statistical calculations. Some calculators even have the ability to do computer algebra. Graphing calculators can be used to graph functions defined on the real line, or higher­dimensional Euclidean space. Currently, basic calculators are inexpensive, but the A modern scientific scientific and graphing models tend to be higher priced. calculator with a dot matrix In 1986, calculators still represented an estimated 41% of the world's LCD display. general­purpose hardware capacity to compute information. This diminished to less than 0.05% by 2007.[1] Contents 1 Design 1.1 Input 1.2 Display output 1.2 Display output 1.3 Memory 1.4 Power source 1.5 Key layout 2 Internal workings 2.1 Example 3 Calculators compared to computers 4 History 4.1 Precursors to the electronic calculator 4.2 Development of electronic calculators 4.3 1970s to mid­1980s 4.3.1 Pocket calculators 4.3.2 Programmable calculators 4.3.3 Technical improvements 4.3.4 Mass market phase 4.4 Mid­1980s to present 5 Use in education 6 Manufacturers 6.1 Current major manufacturers 7 See also 8 Notes 9 References 10 Further reading 11 External links Design Input Modern 2015 electronic calculators contain a keyboard with buttons for digits and arithmetical operations. Some even contain 00 and 000 buttons to make larger or smaller numbers easier to enter. Most basic calculators assign only one digit or operation on each button. However, in more specific calculators, a button can perform multi­function working with key combinations. Display output Calculators usually have liquid­crystal displays (LCD) as output in place of historical vacuum fluorescent displays (VFD). Details are provided in the section Technical improvements. Large­sized figures and comma separators are often used to improve readability. Various symbols for function commands Scientific calculator displays of 1 may also be shown on the display. Fractions such as ∕3 are fractions and decimal equivalents. displayed as decimal approximations, for example rounded to 1 0.33333333. Also, some fractions such as ∕7 which is 0.14285714285714 (to 14 significant figures) can be difficult to recognize in decimal form; as a result, many scientific calculators are able to work in vulgar fractions or mixed numbers. Memory Calculators also have the ability to store numbers into memory. Basic types of these store only one number at a time. More specific types are able to store many numbers represented in variables. The variables can also be used for constructing formulas. Some models have the ability to extend memory capacity to store more numbers; the extended address is referred to as an array index. Power source Power sources of calculators are batteries, solar cells or electricity (for old models) turning on with a switch or button. Some models even have no turn­off button but they provide some way to put off, for example, leaving no operation for a moment, covering solar cell exposure, or closing their lid. Crank­ powered calculators were also common in the early computer era. Key layout Usual basic pocket calculator layout MC Memory Clear MC M+ M­ MR M+ Memory Addition C ± ÷ × M­ Memory Subtraction 7 8 9 ­ MR Memory Recall C or 4 5 6 + All Clear AC 1 2 3 = Clear (last) Entry; sometimes called CE/C: a first press clears the last entry CE 0 . (CE), a second press clears all (C) ± Toggle positive/negative number ÷ Division × Multiplication ­ Subtraction ­ Subtraction + Addition . Decimal point = Result Internal workings In general, a basic electronic calculator consists of the following components:[2] Power source (Mains electricity, battery and/or solar cell) Keypad (Input device) ­ consists of keys used to input numbers and function commands (addition, multiplication, square­root, etc.) Processor chip (microprocessor) contains: Scanning (Polling) unit ­ when a calculator is powered on, it scans the keypad waiting to pick up an electrical signal when a key is pressed. Encoder unit ­ converts the numbers and functions into binary code. X register and Y register ­ They are number stores where numbers are stored temporarily while doing calculations. All numbers go into the X register first. The number in the X register is shown on the display. Flag register ­ The function for the calculation is stored here until the calculator needs it. Permanent memory (ROM) ­ The instructions for in­built functions (arithmetic operations, square roots, percentages, trigonometry etc.) are stored here in binary form. These instructions are "programs" stored permanently and cannot be erased. User memory (RAM) ­ The store where numbers can be stored by the user. User memory contents can be changed or erased by the user. Arithmetic logic unit (ALU) ­ The ALU executes all arithmetic and logic instructions, and provides the results in binary coded form. Decoder unit ­ converts binary code into "decimal" numbers which can be displayed on the display unit. Display panel (Output device)­ displays input numbers, commands and results. LCDs, VFDs, and light­emitting diode (LED) displays use seven segments to represent each digit in a basic calculator. Advanced calculators may use dot matrix displays. A printing calculator, in addition to a display panel, has a printing unit that prints results in ink onto a roll of paper, using a printing mechanism. Example A basic explanation as to how calculations are performed in a simple 4­ function calculator: To perform the calculation 25 + 9, one presses keys in the following sequence on most calculators: 2 5 + 9 = . When 2 5 is entered, it is picked up by the scanning unit, the number 25 is encoded and sent to the X register. Next, when the + key is pressed, the "addition" instruction is also encoded and sent to the flag register. The second number 9 is encoded and sent to the X register. This "pushes" (shifts) the first number out into the Y register. An office calculating When the = key is pressed, a "message" (signal) from the machine with a paper flag register tells the permanent memory that the operation printer. to be done is "addition". The numbers in the X and Y registers are then loaded into the ALU and the calculation is carried out following instructions from the permanent memory. The answer, 34 is sent (shifted) back to the X register. From there it is converted by the decoder unit into a decimal number (usually binary­coded decimal), and then shown on the display panel. Other functions are usually carried out using repeated additions or subtractions. Subtractions are usually carried out by using two's­complement operations. Where calculators have additional functions such as square root, or trigonometric functions, software algorithms are required to produce high precision results. Sometimes significant design effort is required to fit all the desired functions in the limited memory space available in the calculator chip, with acceptable calculation time.[3] Calculators compared to computers The fundamental difference between a calculator and computer is that a computer can be programmed in a way that allows the program to take different branches according to intermediate results, while calculators are pre­designed with specific functions such as addition, multiplication, and logarithms built in. The distinction is not clear­cut: some devices classed as programmable calculators have programming functionality, sometimes with support for programming languages such as RPL or TI­ BASIC. Typically the user buys the least expensive model having a specific feature set, but does not care much about speed (since speed is constrained by how fast the user can press the buttons). Thus designers of calculators strive to minimize the number of logic elements on the chip, not the number of clock cycles needed to do a computation. For instance, instead of a hardware multiplier, a calculator might implement floating point mathematics with code in ROM, and compute trigonometric functions with the CORDIC algorithm because
Load more

Recommended publications
  • Section 10 Flash Technology
    10 FLASH TECHNOLOGY Overview Flash memory technology is a mix of EPROM and EEPROM technologies. The term “flash” was chosen because a large chunk of memory could be erased at one time. The name, therefore, distinguishes flash devices from EEPROMs, where each byte is erased individually. Flash memory technology is today a mature technology. Flash memory is a strong com- petitor to other memories such as EPROMs, EEPROMs, and to some DRAM applications. Figure 10-1 shows the density comparison of a flash versus other memories. 64M 16M 4M DRAM/EPROM 1M SRAM/EEPROM Density 256K Flash 64K 1980 1982 1984 1986 1988 1990 1992 1994 1996 Year Source: Intel/ICE, "Memory 1996" 18613A Figure 10-1. Flash Density Versus Other Memory How the Device Works The elementary flash cell consists of one transistor with a floating gate, similar to an EPROM cell. However, technology and geometry differences between flash devices and EPROMs exist. In particular, the gate oxide between the silicon and the floating gate is thinner for flash technology. It is similar to the tunnel oxide of an EEPROM. Source and INTEGRATED CIRCUIT ENGINEERING CORPORATION 10-1 Flash Technology drain diffusions are also different. Figure 10-2 shows a comparison between a flash cell and an EPROM cell with the same technology complexity. Due to thinner gate oxide, the flash device will be more difficult to process. CMOS Flash Cell CMOS EPROM Cell Mag. 10,000x Mag. 10,000x Flash Memory Cell – Larger transistor – Thinner floating gate – Thinner oxide (100-200Å) Photos by ICE 17561A Figure 10-2.
    [Show full text]
  • Computer Peripheral Memory System Forecast
    OF NBS H^^LK,!,, STAND S. TECH PUBLICATIONS | COMPUTER SUici^CZ^i TECHNOLOGY: COMPUTER PERIPHERAL MEMORY SYSTEM FORECAST QC 100 U57 NBS Special Publication 500-45 #500-45 U.S. DEPARTMENT OF COMMERCE 1979 National Bureau of Standards NATIONAL BUREAU OF STANDARDS The National Bureau of Standards' was established by an act of Congress March 3, 1901 . The Bureau's overall goal is to strengthen and advance the Nation's science and technology and facilitate their effective application for public benefit. To this end, the Bureau conducts research and provides: (1) a basis for the Nation's physical measurement system, (2) scientific and technological services for industry and government, (3) a technical basis for equity in trade, and (4) technical services to promote public safety. The Bureau's technical work is performed by the National Measurement Laboratory, the National Engineering Laboratory, and the Institute for Computer Sciences and Technology. THE NATIONAL MEASUREMENT LABORATORY provides the national system of physical and chemical and materials measurement; coordinates the system with measurement systems of other nations and furnishes essential services leading to accurate and uniform physical and chemical measurement throughout the Nation's scientific community, industry, and commerce; conducts materials research leading to improved methods of measurement, standards, and data on the properties of materials needed by industry, commerce, educational institutions, and Government; provides advisory and research services to other Government Agencies; develops, produces, and distributes Standard Reference Materials; and provides calibration services. The Laboratory consists of the following centers: Absolute Physical Quantities^ — Radiation Research — Thermodynamics and Molecular Science — Analytical Chemistry — Materials Science.
    [Show full text]
  • Digital Preservation Guide: 3.5-Inch Floppy Disks Caralie Heinrichs And
    DIGITAL PRESERVATION GUIDE: 3.5-Inch Floppy Disks Digital Preservation Guide: 3.5-Inch Floppy Disks Caralie Heinrichs and Emilie Vandal ISI 6354 University of Ottawa Jada Watson Friday, December 13, 2019 DIGITAL PRESERVATION GUIDE 2 Table of Contents Introduction ................................................................................................................................................. 3 History of the Floppy Disk ......................................................................................................................... 3 Where, when, and by whom was it developed? 3 Why was it developed? 4 How Does a 3.5-inch Floppy Disk Work? ................................................................................................. 5 Major parts of a floppy disk 5 Writing data on a floppy disk 7 Preservation and Digitization Challenges ................................................................................................. 8 Physical damage and degradation 8 Hardware and software obsolescence 9 Best Practices ............................................................................................................................................. 10 Storage conditions 10 Description and documentation 10 Creating a disk image 11 Ensuring authenticity: Write blockers 11 Ensuring reliability: Sustainability of the disk image file format 12 Metadata 12 Virus scanning 13 Ensuring integrity: checksums 13 Identifying personal or sensitive information 13 Best practices: Use of hardware and software 14 Hardware
    [Show full text]
  • Unit 5: Memory Organizations
    Memory Organizations Unit 5: Memory Organizations Introduction This unit considers the organization of a computer's memory system. The characteristics of the most important storage technologies are described in detail. Basically memories are classified as main memory and secondary memory. Main memory with many different categories are described in Lesson 1. Lesson 2 focuses the secondary memory including the details of floppy disks and hard disks. Lesson 1: Main Memory 1.1 Learning Objectives On completion of this lesson you will be able to : • describe the memory organization • distinguish between ROM, RAM, PROM, EEPROM and • other primary memory elements. 1.2 Organization Computer systems combine binary digits to form groups called words. The size of the word varies from system to system. Table 5.1 illustrates the current word sizes most commonly used with the various computer systems. Two decades ago, IBM introduced their 8-bit PC. This was Memory Organization followed a few years later by the 16-bit PC AT microcomputer, and already it has been replaced with 32- and 64-bit systems. The machine with increased word size is generally faster because it can process more bits of information in the same time span. The current trend is in the direction of the larger word size. Microcomputer main memories are generally made up of many individual chips and perform different functions. The ROM, RAM, Several types of semi- PROM, and EEPROM memories are used in connection with the conductor memories. primary memory of a microcomputers. The main memory generally store computer words as multiple of bytes; each byte consisting of eight bits.
    [Show full text]
  • Quality Checking of Storage Devices Using Moore's
    International Journal of Scientific & Engineering Research Volume 3, Issue 5, May-2012 1 ISSN 2229-5518 Quality Checking of Storage Devices Using Moore’s Law S.Yuvarani, P.Manikandan. ABSTRACT and tape drives. In a computer, storage is the place Today the computer storage devices have where data is held in an electromagnetic or optical been product for different company and different form for access by a computer processor. Computer size. The products to be change the quality of data storage; often called storage or memory refer to product also change. As computer technology computer components, devices and recording media advances, computers became more powerful, while that retain digital data used for computing for some their size decreases of memory chips and increase interval of time. storage capacity. This is because the basic unit of the storage devices has decreased in size. This Likes and dislikes apart, in basic terms, Measurement consists of nano-scale measure for computer storage can be defined as “device or main memory, the secondary storage devices media stores data for later retrieval". From the including magnetic drums, magnetic tapes, definition, we can see that the storage device magnetic disks, and optical disks. These devices possess two features namely "storage" and vary with respect to their speed, memory and "retrieval". A storage facility without retrieval capacity. We have select different files to options seems to be of no use a storage device may interchange the storage devices and measures speed store application programs, Databases, Media files to count time, How to read, write and erase of etc...
    [Show full text]
  • Graduate Announcements 2012-2013 NOTIFICATION of RIGHTS UNDER the FAMILY EDUCATIONAL RIGHTS and PRIVACY ACT (FERPA)
    Graduate Announcements 2012-2013 NOTIFICATION OF RIGHTS UNDER THE FAMILY EDUCATIONAL RIGHTS AND PRIVACY ACT (FERPA) The Family Educational Rights and Privacy Act (FERPA) affords students certain rights with respect to their education records. These rights include: 1. The right to inspect and review the student’s education records within 45 days of the day the University receives a request for access. A student should submit to the registrar, dean, head of the academic department, or other appropriate official, a written request that identifies the record(s) the student wishes to inspect. The University official will make arrangements for access and notify the student of the time and place where the records may be inspected. If the records are not maintained by the University official to whom the request was submitted, that official shall advise the student of the correct official to whom the request should be addressed. (2) The right to request the amendment of the student’s education records that the student believes are inaccurate, misleading, or otherwise in violation of the student’s privacy rights under FERPA. A student who wishes to ask the University to amend a record should write the University official responsible for the record, clearly identify the part of the record the student wants changed, and specify why it should be changed. If the University decides not to amend the record as requested, the University will notify the student in writing of the decision and the student’s right to a hearing regarding the request for amendment. Additional information regarding the hearing procedures will be provided to the student when notified of the right to a hearing.
    [Show full text]
  • Recovering Data from Failing Floppy Disks
    Chapter 3 RECOVERING DATA FROM FAILING FLOPPY DISKS Frederick Cohen and Charles Preston Abstract As floppy disks and other similar media age, they may lose data due to a reduction in the retention of electromagnetic fields over time, mainly due to environmental factors. However, the coding techniques used to write data can be exploited along with the fault mechanisms themselves to successfully read data from failing floppy disks. This paper discusses the problem of recovering data from failing floppy disks and describes a practical example involving a case of substantial legal value. Keywords: Floppy disks, field density loss, weak bits, data recovery 1. Introduction This paper discusses a method for recovering data from floppy disks that are failing due to “weak bits.” It describes a repetitive read tech- nique that has successfully recovered data in forensic cases and dis- cusses the analysis of the results of repetitive reads in terms of yielding forensically-sound data. This technique is not new; however, neither the technique nor the analysis necessary to support its use in legal matters have been published. The case discussed in this paper involved a fifteen-year-old floppy disk, which contained the only copy of the binary version of a software pro- gram that was subject to intellectual property claims of sufficient value to warrant recovery beyond the means normally used by commercial re- covery firms. After attempts to read the disk by these firms had failed, the disk was given to the authors to use more rigorous and possibly destructive data recovery methods, subject to court approval.
    [Show full text]
  • RADIO Electronica 1 September 1973
    21e Jaargang RADIO electronica 1 september 1973 ONAFHANKELIJK TIJDSCHRIFT VOOR PRAKTISCHE ELEKTRONICA f 1,70 VERSCHIJNT TWEEMAAL PER MAAND j2september hamsterdam Rai ■ Va-,,:. Si2: ■ \i SU V 7\S 26/9 tm 4/10 rai amsterdam © het instrument 1973I Miniscoop type 211 van Tektronix ___________________________________________________________ ••«*? Amroh componenten ') 4 • * Alp *UM iU 'M AMROH B.V. Telex 15171 Tel. (02942) - 1951* Muiden 17 ONAFHANKELIJK TIJDSCHRIFT VOOR PRAKTISCHE ELEKTRONICA 1 september 1973 waarin opgenomen „ELECTRON DIGEST", orgaan van het Internationaal Documentatie Centrum voor Elektronische Toepassingen 21e Jaargang (IDOCET) Antwerpen Uitgave van: Kluwer Technische Tijdschriften B.V. S Redactie, administratie en advertentie- afdeling Polstraat 9 - Postbus 23 Deventer-6600 - Tel. 0 5700 - 7 55 22 Giro 86 12 21 Bankrelatie: In dit nummer Algemene Bank Nederland N.V., Deventer No. 596247265 Redactie: Telecommunicatietechniek 585 NOS en quadrofonie C. J. Bakker 611 Draadloze ultrasonische afstandbe­ J. G. Smilde diening voor KTV Medewerkers in Nederland en België: ir. E. A. L. M. Aerts J. H.Jansen W. Arckens drs W. D M Janssen Onderwijs en didactiek 589 Hoger informatica onderwijs en be- R. Bakker H. Jekel W. De Boeck Th. R. J. Koehoorn drijfsinformatica onderwijs ir. W. v. Bokhoven M. Leeuwin 600 44e AES-conventie J. Bron H. Leydens 609 8ste Int. TV-Symposium H. E. Charlouis ing. Th C. Lof (L&S IP) W W. Diefenbach W. Olthoff C. L. Doesburg H Saeys R. Y. Drost drs. F. M. Schimmel Elektroakoestiek 593 Platenspeler met tangentiale arm E. J. R. Engelen mg. J. M. Spekreijse (L&S'IP) 601 Quadrofonie J. H. M. Goddijn F, A.
    [Show full text]
  • OF the 1980S
    THAT MADE THE HOME COMPUTER REVOLUTION OF THE 1980s 23 THAT MADE THE HOME COMPUTER REVOLUTION OF THE 1980s First published in 2021 by Raspberry Pi Trading Ltd, Maurice Wilkes Building, St. John’s Innovation Park, Cowley Road, Cambridge, CB4 0DS Publishing Director Editors Russell Barnes Phil King, Simon Brew Sub Editor Design Nicola King Critical Media Illustrations CEO Sam Alder with Brian O Halloran Eben Upton ISBN 978-1-912047-90-1 The publisher, and contributors accept no responsibility in respect of any omissions or errors relating to goods, products or services referred to or advertised in this book. Except where otherwise noted, the content of this book is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported (CC BY-NC-SA 3.0). Contents Introduction. 6 Research Machines 380Z. 8 Commodore PET 2001. 18 Apple II. 36 Sinclair ZX80 and ZX81. 46 Commodore VIC-20 . 60 IBM Personal Computer (5150). 78 BBC Micro . 90 Sinclair ZX Spectrum. 114 Dragon 32. 138 Commodore 64. 150 Acorn Electron . .166 Apple Macintosh . .176 Amstrad CPC 464. 194 Sinclair QL . .210 Atari 520ST. 222 Commodore Amiga. 234 Amstrad PCW 8256. 256 Acorn Archimedes . .268 Epilogue: Whatever happened to the British PC? . .280 Acknowledgements . 281 Further reading, further viewing, and forums. 283 Index . .286 The chapters are arranged in order of each computer’s availability in the UK, as reflected by each model’s date of review in Personal Computer World magazine. Introduction The 1980s was, categorically, the best decade ever. Not just because it gave us Duran Duran and E.T., not even because of the Sony Walkman.
    [Show full text]
  • How 1980S Britain Learned to Love the Computer
    Lean, Tom. "Computers for the Man in the Street." Electronic Dreams: How 1980s Britain Learned to Love the Computer. London: Bloomsbury Sigma, 2016. 61–88. Bloomsbury Collections. Web. 30 Sep. 2021. <http://dx.doi.org/10.5040/9781472936653.0006>. Downloaded from Bloomsbury Collections, www.bloomsburycollections.com, 30 September 2021, 11:40 UTC. Copyright © Tom Lean 2016. You may share this work for non-commercial purposes only, provided you give attribution to the copyright holder and the publisher, and provide a link to the Creative Commons licence. CHAPTER THREE Computers for the Man in the Street arly in 1980, adverts began appearing in British newspapers Efor something rather unusual. Sandwiched between pages of economic and social troubles, Thatcherite politics and Cold War paranoia was an advert for a small white box. It looked a little like an overgrown calculator, but declared itself to be the Sinclair ZX80 Personal Computer, and could be bought, ready made, for just £ 99.95. Despite the implausibly low price, the ZX80 was not only a ‘ real computer ’ , but one that cut through computer ‘ mystique ’ to teach programming, and was so easy to use that ‘ inside a day you ’ ll be talking to it like an old friend’ , or so the advert said. It was an impressively crafted piece of marketing, creating an impression of aff ordability and accessibility, ideas hitherto rarely associated with computers. The little white box, and the bold claims that sold it, marked the beginning of a redefi nition of computers as aff ordable and everyday appliances for the masses. At the time microcomputers were broadly split between two basic types.
    [Show full text]
  • Comprehensive Index of the Journal of the Oughtred Society by Barry Dreikorn, Updated Jan
    Comprehensive Index of The Journal of the Oughtred Society by Barry Dreikorn, Updated Jan. 9, 2010 Vol 0, No.0, Pilot Issue 1991 Jos-index-v0-n0- 1991 -item 1 -page 1 .txt Title: The Journal of the Oughtred Society Author: Editor Summary: Background leading to, the reasons for, and the plan to start formal publication of the Journal of the Oughtred Society Keywords: Journal of the Oughtred Society Jos-index-v0-n0- 1991 -item2-page3 .txt Title: The June Meeting in Oakland Author: Rodger Shepherd Summary: Meeting of nine attendees exhibiting their collections and discussion of supporting slide rule collecting in future by: (a) forming a society, (b) forming a publication, or (c) doing both. Keywords: slide rule collecting, publishing, organizing, standards Jos-index-v0-n0- 1991 -item3 -page5 .txt Title: Proposed Projects Author: Anon Summary: A second meeting, reprinting Cajori’s book on slide rules and allied instruments, booklets listing slide rules and their makers, attracting more people. Keywords: second meeting, reprints, Cajori, booklets, makers, membership Jos-index-v0-n0- 1991 -item4-page6.txt Title: Saul Moskowitz – In Memoriam Author: Bob Otnes Summary: Recalling Saul Moskowitz, noted antique instrument dealer and publisher of noted catalogs for over 20 years, upon his unexpected death. Keywords: Saul Moskowitz, antique scientific instruments, catalogs Jos-index-v0-n0- 1991 -item5-page7.txt Title: The Otis King Slide Rule Author: Anon Summary: Description of Otis King cylindrical slide rule, its basic operation, models, years of manufacture, figure showing two models. Keywords: Otis King, cylindrical slide rule, British patent, serial numbers, how to use.
    [Show full text]
  • Gottfried Wilhelm Leibniz (1646 – 1716)
    Gottfried Wilhelm Leibniz (1646 – 1716) From Wikipedia, the free encyclopedia, http://en.wikipedia.org/wiki/Gottfried_Leibniz Leibniz occupies a prominent place in the history of mathematics and the history of philosophy. He developed the infinitesimal calculus independently of Isaac Newton, and Leibniz's mathematical notation has been widely used ever since it was published. He became one of the most prolific inventors in the field of mechanical calculators. While working on adding automatic multiplication and division to Pascal's calculator, he was the first to describe a pinwheel calculator in 1685 and invented the Leibniz wheel, used in the arithmometer, the first mass-produced mechanical calculator. He also refined the binary number system, which is at the foundation of virtually all digital computers. In philosophy, Leibniz is mostly noted for his optimism, e.g., his conclusion that our Universe is, in a restricted sense, the best possible one that God could have created. Leibniz, along with René Descartes and Baruch Spinoza, was one of the three great 17th century advocates of rationalism. The work of Leibniz anticipated modern logic and analytic philosophy, but his philosophy also looks back to the scholastic tradition, in which conclusions are produced by applying reason to first principles or prior definitions rather than to empirical evidence. Leibniz made major contributions to physics and technology, and anticipated notions that surfaced much later in biology, medicine, geology, probability theory, psychology, linguistics, and information science. He wrote works on politics, law, ethics, theology, history, philosophy, and philology. Leibniz's contributions to this vast array of subjects were scattered in various learned journals, in tens of thousands of letters, and in unpublished manuscripts.
    [Show full text]