Milestones in Analog and Digital Computing

The chapter “Introduction” describes the goal of the book and the period of time covered by the presentations. It conveys an overview of new and exciting findings of objects (above all calculating machines) and documents and provides insight into their origins. The book focuses on the history predating the emergence of analog and digital computer technology and the early history of their development, automaton construction (automaton figures and musical automatons), and selected scientific instruments from the areas of astronomy, surveying, and measurement of time. Special attention is given to the non-English-speaking countries. It is not the intention of the book to present the entire history without interruption. Instead, the emphasis is on the highlights and the most significant achievements. Overviews in the form of tables facilitate the study of the material. Lines of development depict coherent relationships. Instead of a treatment of the most recent era in computer science, the subjects of digital transformation and artificial intelligence are discussed at length. Numerous step-by-step operating instructions for analog and digital calculating devices round out the volume.

The chapter “Basic Principles” explains fundamental concepts, such as analog and digital computers, numerical and physical quantities, counting and measuring, conditional instructions, decimal and binary computers, parallel and serial computers, hybrid computers, special-purpose and universal computers, punched card machines, bookkeeping machines, mechanical calculating machines, adding machines, relay, vacuum tube, magnetic storage, direct and indirect subtraction, direct and indirect multiplication, sequence and program control, automation, commercial data processing, scientific computing, stepped drum, pinwheel, counting board, bead frame, slide rule, sector, curvimeter, planimeter, and pantograph. Numerous features serve to characterize analog and digital calculating devices in detail. The examples are taken from the fields of mathematics (difference engine), astronomy (armillary sphere, astrolabe, terrestrial globe, celestial globe, planisphere), geodesy (pedometer, odometer), and time measurement (planetarium clock). The evolution of the digital system is briefly described.

The following topics are also discussed: algorithms, artificial intelligence, artificial neural networks, big data, blockchains, booking platforms, data privacy, the digital transformation, digitization, drones, electronic commerce, the Internet of Things, machine learning, quantum computers, ride-hailing services, robots, self-driving cars, smartphones, social networks, and voice assistants.

This chapter “The Coming of Age of Arithmetic” traces the tedious journey from the tally stick, through the bead frame, to the smartphone. To this day the importance of the Ishango bone discovered in Africa is puzzling. The tally stick was a digital memory with which falsification was hardly possible. Among popular calculating aids was also the (digital) quipu. Since time immemorial the fingers have served for counting and calculating. An (digital) abacus utilizes either lines and counters (counting board) or staffs with beads (bead frame). Unlike the Roman number system, the use of the Roman hand abacus is simple. Although there was no symbol for zero, one could represent this number on the “pocket calculator” along with ones, tens, hundreds, etc. Once widespread logarithmic analog calculating devices, such as the slide rule, circular slide rule, and cylindrical slide rule, disappeared 50 years ago, as did mechanical desktop calculators. The difference between numerical and graphical computation is also described. A special form is nomography. The omnipresent portable smartphone is regarded as an extremely versatile tool. The evolution of certain mathematical instruments is illustrated in the form of lines of development.

The chapter “Classification of Calculating Aids and Related Instruments” elaborates a classification of analog and digital mechanical and electronic calculating devices and machines that eliminates contradictions as well as possible. This also considers plotting and measuring devices, as well as astronomical instruments. Calculations are performed with all of these tools. The chapter describes the differences between calculating aids and calculating machines, adding and calculating machines, and mathematical machines and mathematical instruments. Planimeters, pantographs, sectors, proportional compasses, protractors, clinometers, coordinatographs, quadrants, sextants, and octants are introduced. Furthermore, the intercept theorems are explained. Among the popular calculating aids are also mathematical tables. Finally, the classification is recapitulated in the form of a list and a table.

The chapter “Chronology” describes selected pivotal achievements from the pre- and early history of computer science and automaton construction. The history of computing technology begins with counting on the fingers, the notched bone, the tally stick, the quipu, and the abacus and ranges from the slide rule and the mechanical calculating machine to the stored program electronic computer, the Internet, the World Wide Web, the smartphone, and the quantum computer. The earliest known calculating aids were already digital: fingers, the tally stick, the quipu, and the abacus. The most important analog device was the (logarithmic) slide rule.

This chapter deals with the question who invented or discovered what and when. Important contributions of women (e.g., Ada Lovelace and Grace Hopper) are included. The achievements of women during the Second World War (e.g., cracking the Enigma ciphertexts in Bletchley Park, UK, and programming the giant Eniac computer in Philadelphia) were of great importance. The global overview by country traces the pre- and early history of calculating and computing technology. A number of unrecognized and unknown visionaries are mentioned as well. Along with analog and digital mathematical aids, numerous drawing and measuring devices and (partly programmable) automaton figures are described. Selected manufacturers of calculating and computing devices are also mentioned. A chronological table summarizes pathbreaking accomplishments.

This chapter presents a global overview of important conferences in the early days of computer science. From 1945 on, these were held mostly in the USA. In 1951 a large international conference took place in Paris which, in spite of comprehensive documentation (however in French), remains virtually unknown. The first significant conference on the history of computer science was organized in 1976. In 2012 numerous events commemorated the 100th birthday of Alan Turing. The first institutes for computing technology, which arose especially in the USA and the UK, are listed as well. Worldwide, there are several associations focusing on the history of calculating and computing technology.

The chapter “Global Overview of Early Digital Computers (Tables)” gives an overview of the first (mechanical) relay and (electronic) vacuum tube computers. These are presented in alphabetical order and (in abbreviated form) in chronological order (1939–1953), together with the most important attributes and detailed descriptions. Examples are the Bell Labs mechanical relay computer (USA), the Harvard Mark perforated tape controlled relay machine (USA), the ABC special-purpose electronic computer (USA), the giant Eniac plug-programmed vacuum tube computer (USA), the stored program Edvac (USA) and Edsac (UK) computers, the Princeton IAS computer (USA), which served as a model for many replicas, the decade-long top secret Colossus (UK), used for the deciphering of coded messages, the Ace machine, built according to the designs of Alan Turing (UK), the Zuse Z3 binary computer with floating point notation (Germany), and the mass-produced Ferranti Mark (UK), as well as the Univac (USA), IBM 650 and 701 (USA), and Leo (UK).

The chapter “Museums and Collections” gives the reader detailed information about the collections of important museums (e.g., in Athens, Beijing, Berlin, Bletchley Park, Bonn, Clermont-Ferrand, Dresden, Florence, Kassel, London, Madrid, Manchester, Melbourne, Milan, Mountain View, Munich, Neuchâtel, Ottawa, Oxford, Paderborn, Paris, Stockholm, Strasbourg, Vienna, and Washington). Most of these are museums of science, technology, and art. The chapter examines analog and digital calculating aids, historical automatons, and robots, as well as scientific instruments. The first mechanical calculating aids (Schickard, Pascal, Morland, and Leibniz) date from the seventeenth century. The chapter also describes where originals and reconstructions of famous objects (e.g., the Antikythera mechanism, Babbage’s difference engine, the Colossus, the Csirac, Hollerith’s punched card equipment, the Johnniac, the Leibniz machine, the Pascaline, the Pilot Ace, the Roman hand abacus, Schickard’s calculating clock, the Thomas arithmometer, the Turing-Welchman Bombe, and the Zuse Z4) are found. Furthermore, the question of which are the oldest surviving mechanical and electronic computers is addressed. The early one-, two-, and four-function machines are summarized in overview tables. The world’s most magnificent calculating machines, including the replicas of Roberto Guatelli, are described. The oldest large museums of technology (Dresden and Paris) date from the eighteenth century. Their forerunners were often royal wonder and curiosity cabinets from the early modern era. Scientific societies were founded as early as the seventeenth century and mathematical associations from the nineteenth century. The first world exhibition was the Great Exhibition, which took place in London in 1851. Today, the most important collections, and in part also object databases, are accessible on the Internet.

The chapter “The Antikythera mechanism” describes an astronomical calculating machine discovered in Greece in 1901. The sensational finding only gradually revealed its secrets in recent decades. Some consider this technical marvel to be the first (analog) computer. Where it was built and who invented it remain a mystery. Numerous material and virtual reconstructions have been made in an attempt to explain the functioning of the device.

The chapter “Schwilgué’s Calculating Machines” deals with the largely unknown mathematical machines of Jean-Baptiste Schwilgué, the creator of the present astronomical clock of the Strasbourg cathedral. We have him to thank for the earliest surviving keyboard adding machine (patented in 1844) and a mechanical “process” calculator.

The chapter “The Thomas Arithmometer” describes the world’s first successful, industrially manufactured calculating machine. The mechanical stepped drum machine of Charles Xavier Thomas is capable of all four basic arithmetic operations. It was exhibited at the Great Exhibition of 1851 in London.

The chapter “The Curta” introduces still another technical marvel. The highly gifted Austrian engineer Curt Herzstark created a picture-perfect “pepper mill,” the tiniest mechanical calculating machine in the world. The design drawings were drafted in the Buchenwald concentration camp. The round-shaped calculator was manufactured in high numbers in Liechtenstein until the beginning of the 1970s. However, the inventor was cheated out of his life’s work. Only recently, high-quality drawings for the Multiple Curta, the world’s smallest mechanical parallel calculator, came to light. The University of Birmingham constructed a 12-fold Curta in 1953. The Curta is considered the crowning achievement of the 350-year history of mechanical calculating machines. The stepped drum devices remain completely functional to this day.

The chapter “Slide Rules” describes once widespread mathematical instruments designed on the basis of the logarithms discovered by Jost Bürgi (Switzerland) and John Napier (Scotland). These instruments reduce multiplication to the addition and division to the subtraction of line segments. One also speaks of nomography. There are different types of instruments: linear slide rules, circular slide rules, cylindrical slide rules, and pocket-watch slide rules. Cylindrical slide rules have scale sections arranged parallel to each other or in a helical arrangement. This analog calculating instrument dates from the seventeenth century and was in use until the 1970s. The English mathematician William Oughtred is considered the inventor of the slide rule. The largest mass-produced cylindrical slide rule, the Loga calculator, has a scale length of 24 m. The longer the scale, the greater the accuracy of the instrument. For the Swiss-made Loga cylindrical slide rules, the serial numbers are related to the scale length.

The chapter “Historical Automatons and Robots” depicts a wealth of magnificent mechanical automatons. Of particular interest are automaton figures (human or animal automatons), musical automatons (mechanical musical instruments), handwriting automatons, drawing automatons, chess automatons, mechanical robots, and punched card controlled looms. Included are clocks (sand glasses, sundials, night clocks, longcase clocks, pendulum clocks, tabernacle clocks, table clocks, pocket watches, astronomical clocks, picture clocks, and automaton clocks) and early typewriting machines. Some of these objects were programmable (e.g., with perforated tapes, program cylinders, and cams). Among the best known automaton builders are James Cox, Pierre and Henri-Louis Jaquet-Droz, Peter Kintzing, Friedrich Knaus, Hans Schlottheim, and Jacques Vaucanson. The origin of a musical automaton figure in the Beijing Palace Museum attributed to Timothy Williamson is unclear. More than 500 years ago, Leonardo da Vinci designed several “robots” (a mechanical knight, a mechanical lion, and a self-propelled cart). Numerous reconstructions of these have been made. Some automaton figures dating from the eighteenth century are still fully functional.

Since overviews regarding other manufacturing countries such as the USA and Germany are already available, the chapter “Mechanical Calculating Aids” is essentially limited to Switzerland. This chapter describes calculating tables, slide bar adders, and mechanical calculating machines, for example, the Millionaire, Madas, Precisa, and Stima brands. A tabular overview lists the attributes of all known products from Switzerland. The legendary Millionaire, a partial-product multiplying machine, was the first commercially successful direct multiplying machine. On the basis of serial numbers and previously unknown documentation from the H.W. Egli AG, Zurich, an attempt is made to date this four-function calculating machine. A global survey reveals information about the known Millionaire machines, and the catalog of the Schweizer Mustermesse Basel, which was issued every year from 1917 (founding) to 2019 (final year), was evaluated. Little information is available in regard to piece numbers, prices, and patents.

The chapter “Technological, Economic, Social, and Cultural History” illustrates the role and the transformation of technological and scientific history. The history of science and technology is now mostly presented within the scope of the humanities, frequently with emphasis on the economic and social aspects and consequently not able to satisfy a number of requirements. Although technology and science greatly influence our lives, very few academic chairs and courses of study are concerned with their history. In spite of this, deeper specialized scientific and technical knowledge is decisive for museums and other collections, especially for preserving the cultural heritage. For some time, there has been a renewed revival of interest in material history. Patent protection is treated as well. Furthermore, information is given about the lifespan of analog and digital calculating aids.

It follows from chapter “Preserving the Technical Heritage” that much material and immaterial cultural heritage has been lost in the wake of rapid technical developments. The lifespan of objects decreases. Museums are bursting at the seams. When documentation is missing, it is not always known which objects are of relevance. At some sites a reevaluation of often neglected scientific collections is in progress. Maintaining the functionality of mechanical automatons and electronic computers is extremely time-consuming. The associations committed to the preservation of the technical cultural heritage have difficulty finding younger persons to carry on their work. Thanks to digitization many old and rare books, journals, maps, and plans are globally accessible online. However, since the lifespans of currently available electronic data carriers are short, the problems of long-duration digital archival remain. Furthermore, programs and operating systems, as well as document formats, continuously change. Due to the immense amounts of data, it is not possible to save all meaningful Internet-based information for posterity. The deluge of data leaks shows that external data keeping (clouds) is unreliable.

Chapter “Operating Instructions” gives detailed step-by-step instructions for the most important analog and digital calculating devices and mechanical calculating machines, making it possible to operate historical mathematical aids once again. In many cases, no operating instructions have been preserved. Failure to use such instruments can result in damage. The operating instructions range from heavy stationary desktop machines to lightweight portable pocket calculators, from the abacus (bead frame) through Napier’s bones and slide rules (linear, circular, and cylindrical slide rules), sectors, disc adding machines, and slide bar adders to keyboard adding machines (Schwilgué single-digit adding machine), stepped drum machines (Thomas arithmometer, Madas, Curta), pinwheel machines (Odhner, Brunsviga), and direct multiplying machines (The Millionaire). According to the model, numerical input is by wheels, stylus, setting levers, or keys. The use of the Chinese, Japanese, and Russian bead frames differs only slightly. This is also true for the children’s counting frame. Details for the use of the Roman hand abacus are given in Sect. 3.​3. The numerical notation with the calculating table is described in Sect. 3.​4. Section 4.​6 explains the pantograph. Instructions for the use of proportional compasses are given in Sect. 4.​8. All instructions are derived from trying out. These make very clear how arduous computation was for thousands of years.

The chapter “Who was the inventor of the computer” begins with the explanation of terms such as algorithm, compiler, computer, Turing machine, universal computer, self-modifying program, stored program, and von Neumann computer. A number of matters of dispute are also addressed: Who invented the von Neumann computer and the compiler when and where? Who were the originators of the stored program and automatic programming? How great was Turing’s influence on the construction of computers? Was Ada Lovelace actually the first programmer? Which were the most important early publications on computer construction and programming? Which computer pioneers were behind these achievements? The computer had numerous creators in several countries and also many forerunners. There were naturally also setbacks with the construction of computers. Some ascribe great meaning to priority, e.g., in relation to the stored program computer. Early relay and vacuum tube computers in Europe and the USA are summarized along with their follow-on machines. Automatic computers influencing future developments are discussed and the first commercially produced computers introduced. Emerging European and US transistor computers are also treated. A chronological table gives information about early mechanical and electronic digital computers from the USA, Australia and Europe. The chapter concludes with a list of selected anniversaries relating to the history of computing.

The chapter “Computer Development in Germany” provides an overview of Zuse’s relay, vacuum tube, and transistor machines. The chapter also mentions his “Plankalkül” programming language and his special-purpose computers. Relay and vacuum tube computers from Darmstadt, Dresden, Göttingen, Jena, and Munich are presented, as well as the first German transistor computers (Siemens, Standard Elektrik Lorenz, and Telefunken). In Germany there were also analog computers (e.g., from Telefunken and Dornier). The chronological table lists early German relay, vacuum tube, and transistor computers.

The chapter “Computer Development in the UK” focuses on the events in Bletchley Park, with particular emphasis on the Enigma cryptographic machine. For decades only little was known about the Turing-Welchman Bombe and the Colossus machines, with the help of which the coded radio messages of the Nazis were cracked and for which functional reconstructions have been built. The portrayal of these events includes a list of code names and difficult to understand specialized expressions as well as a chronological table. The development of computers at the universities in Manchester, Cambridge, and London (Birkbeck College) is also described. Familiar computer brands were, e.g., Elliott, Ferranti, and Leo. The Harwell machine is considered the oldest still functional relay computer. Early transistor computers were built in Manchester. A chronological table of the first British relay and vacuum tube computers rounds out the presentation.

As the chapter “Computer Development in Switzerland” depicts, the history of computer science in Switzerland began with the founding of the Institute for Applied Mathematics at the ETH Zurich. Important was the leasing of the program-controlled Zuse Z4 relay computing machine. Much of the chapter is devoted to the relationship with Zuse. Formidable problems arose with the construction of the Ermeth electronic computer, especially with the magnetic drum memory. The author attempts to answer the question “why did a Swiss computer industry fail to emerge in the 1950s?” Remington Rand (Zurich) contracted the Zuse KG to mass produce the M9 calculating punch. The chapter also touches on the development of the first Swiss transistor computer, the Cora. Finally, the most important early Swiss computer pioneer, Heinz Rutishauser, is briefly introduced.

This chapter compiles a wealth of largely unknown and difficult to access original documents: the basic contract and the leasing agreement for the Z4 relay computer, as well as the test report and final bill for the Z4, the project proposal for the building of the Ermeth vacuum tube computer, and the license agreement for the marketing of the Ermeth.

The chapter “The Global Evolution of Computer Technology” deals with the development of computer technology in a number of selected countries: Austria, France, Italy, Russia, Spain, Sweden, and the USA. Furthermore, achievements in computer technology in Argentina, Australia, Belgium, Canada, China, India, Israel, Japan, Mexico, and the Netherlands are described. A chronological table provides an overview of early American relay, vacuum tube, and transistor computers.