Is it true, as Microsoft wrote in its brief, that computers are at heart just a "collection of tiny on-off switches--usually in the form of transistors"? Or that "The role of software is simply to automate the reconfiguration of the electronic pathways that was once done manually by the human operators of ENIAC"? Are computers just a modern equivalent to the telegraph or the Jacquard loom, a series of on-off switches, as the brief asserts?

Or is that hyberbole, and technically inaccurate hyperbole? How do modern computers really work? What impact did the discovery of the universal Turing machine have on how computers work, compared to prior special-purpose computers like ENIAC? What are the differences between how analogue and digital computers work? We have heard from the lawyers, but what about from those whose area of expertise is the tech? I think you'll see how this technical information ties in with the questions the US Supreme Court would like answered -- presumably accurately -- as to whether or not software should be patentable and whether computers become special purpose machines when software is run on them. Po1R's collected some very useful references from experts. Feel free to add more references in your comments.

Update: Groklaw user fncp sent us urls demonstrating that the ENIAC was doing symbolic manipulations. It didn't perform calculations in the manner of a differential analyzer:

Official history of the ENIAC

The ENIAC on a chip project

The ENIAC was one of the first electronic devices able to do symbolic manipulations. What it didn't do is store programs in the same memory as data. This is the crucial step that was missing to incorporate the principles of an universal Turing machine into an actual device. It is only when this step was accomplished that the possibility of programs manipulating or generating other programs becomes possible. Research on how to implement this possibility led to the development of what is now known as the Von Neumann computer architecture.

The Stanford Encyclopedia of Philosophy writes on this history:

In 1944, John von Neumann joined the ENIAC group. He had become ‘intrigued’ (Goldstine's word, [1972], p. 275) with Turing's universal machine while Turing was at Princeton University during 1936–1938. At the Moore School, von Neumann emphasised the importance of the stored-program concept for electronic computing, including the possibility of allowing the machine to modify its own program in useful ways while running (for example, in order to control loops and branching). Turing's paper of 1936 (‘On Computable Numbers, with an Application to the Entscheidungsproblem’) was required reading for members of von Neumann's post-war computer project at the Institute for Advanced Study, Princeton University (letter from Julian Bigelow to Copeland, 2002; see also Copeland [2004], p. 23). Eckert appears to have realised independently, and prior to von Neumann's joining the ENIAC group, that the way to take full advantage of the speed at which data is processed by electronic circuits is to place suitably encoded instructions for controlling the processing in the same high-speed storage devices that hold the data itself (documented in Copeland [2004], pp. 26–7). In 1945, while ENIAC was still under construction, von Neumann produced a draft report, mentioned previously, setting out the ENIAC group's ideas for an electronic stored-program general-purpose digital computer, the EDVAC (von Neuman [1945]). The EDVAC was completed six years later, but not by its originators, who left the Moore School to build computers elsewhere. Lectures held at the Moore School in 1946 on the proposed EDVAC were widely attended and contributed greatly to the dissemination of the new ideas.

Von Neumann was a prestigious figure and he made the concept of a high-speed stored-program digital computer widely known through his writings and public addresses. As a result of his high profile in the field, it became customary, although historically inappropriate, to refer to electronic stored-program digital computers as ‘von Neumann machines’.

Reducto ad absurdum
Authored by: polymath on Sunday, November 01 2009 @ 11:04 AM EST

The last extract reveals that Microsoft's brief fails even on its own terms.

While Morse's telegraph was patentable the sequence of 1's and 0's used to send any given message was not patentable. While Jacquard's loom was patentable the arrangement of holes on the cards that produced cloth was not patentable. While the machines for manipulating Hollerith cards were patentable the arrangement of holes representing the information was not patentable. Even a printing press is patentable subject matter but the arrangement of type to produce a story is not patentable. Likewise computer hardware may be patentable subject matter but the pattern of transistor states that represent programs and data are not patentable.

All of those patterns are the proper subject matter of copyright law. Neither patents nor copyright protect ideas or knowledge and we are free to create new implementations and/or expressions of those ideas.

To allow a patent on a program is akin to allowing a patent on thank you messages, floral fabric designs, census information, or vampire stories. It is simply nonsense.

An Observation On the Amicus Curiae Brief from Microsoft, Philips and Symantec

~ by PolR

I have noticed something about PDF the amicus brief from Microsoft, Philips and Symantec submitted to the US SUpreme Court in the In re Bilski case. This amicus brief relies on a particular interpretation of the history of computing and on its own description of the inner workings of a computer to argue that software should be patentable subject matter. I argue that both the history and the description of the actual working of a computer is inaccurate.

I note that the authors of the brief are lawyers. They are not, then, presumably experts in the history of computing. The statements from the brief are in direct contradiction with information found at expert sources I've collected here.

How Do Computers Work According to the Brief?

Here is how the brief describes how computers work:

The fantastic variety in which computers are now found can obscure the remarkable fact that every single one is, at its heart, a collection of tiny on-off switches--usually in the form of transistors. See generally David A. Patterson & John L. Hennessy, Computer Organization and Design (4th ed. 2009); Ron White, How Computers Work (8th ed. 2005). Just as the configuration of gears and shafts determined the functionality of Babbage's computers, it is the careful configuration of these on-off switches that produces the complex and varied functionality of modern computers.

Today, these on-off switches are usually found in pre-designed packages of transistors commonly known as "chips." Thin wafers of silicon, chips can contain many millions of transistors, connected to one another by conductive materials etched onto the chip like a web of telephone lines. They are organized such that they can be turned on or off in patterned fashion, and by this method, perform simple operations, such as turning on every transistor whose corresponding transistor is off in the neighboring group. From these building blocks, mathematical and logical operations are carried out. Patterson & Hennessy, supra, at 44-47 & App. C.

The challenge for the inventor is how to use these transistors (and applying the principles of logic, physics, electromagnetism, photonics, etc.) in a way that produces the desired functionality in a useful manner. Computer programming is an exercise in reductionism, as every feature, decision, and analysis must be broken down to the level of the rudimentary operations captured by transistors turning on and off. This reductionism is matched by the detail with which transistors must be configured and instructed to carry out the thousands or millions of operations required by the process.

Early electronic computers were "programmed" by laboriously rewiring their electrical pathways so that the computer would perform a desired function. ENIAC--the first general-purpose electronic digital computer, functioning at the mid-point of the Twentieth Century -- could take days to program, with operators physically manipulating the switches and cables. Patterson & Hennessy, supra, at 1.10. [ed: graphic of ENIAC]

Fortunately, this is no longer the case. Transistors, packaged onto silicon chips, permit electronic manipulation of the pathways between them, allowing those pathways to be altered to implement different processes without direct physical manipulation. The instructions for this electronic reconfiguration are typically expressed in computer software. See Microsoft Corp. v. AT&T Corp., 550 U.S. 437, 445-46 (2007) (noting that, inter alia, Windows software renders a general-purpose computer "capable of performing as the patented speech processor"). To allow more sophisticated control over the millions of transistors on a chip, inventors rely on a multi-layered scheme of pre-designed software "languages" that help bridge the gap between the on-off language of the transistor and the words and grammar of human understanding. These allow control of the transistors on a chip at various levels of specificity, ranging from "machine language," which allows transistor-level control, to "programming languages," which allow operations to be defined through formal syntax and semantics that are more easily understood by humans. Each language pre-packages the mathematical and logical operations that are most useful for the users of that particular language. See Patterson & Hennessy, supra, at 11-13, 20-21, 76-80.

Using these languages, the inventor can create "software" that defines the operations of semiconductor chips and other hardware. These operations are the steps of a computer-implemented process. The role of software is simply to automate the reconfiguration of the electronic pathways that was once done manually by the human operators of ENIAC.

What is the Glaring Error in this Description?

The brief fails to mention a most important mathematical discovery -- the universal Turing machine -- and how it influenced the development of the computer. The ENIAC didn't use this mathematical discovery, while computers built afterwards use it. Because of the discovery of Turing, the programming of modern computers doesn't operate under the same principles as the ENIAC.

An article titled "Computability and Complexity", found on The Stanford Encyclopedia of Philosophy's website, describes the contribution of universal Turing machines to the development of computers:

Turing's construction of a universal machine gives the most fundamental insight into computation: one machine can run any program whatsoever. No matter what computational tasks we may need to perform in the future, a single machine can perform them all. This is the insight that makes it feasible to build and sell computers. One computer can run any program. We don't need to buy a new computer every time we have a new problem to solve. Of course, in the age of personal computers, this fact is such a basic assumption that it may be difficult to step back and appreciate it.

According to Martin Davis, Professor Emeritus, Department of Computer Science Courant Institute of Mathematical Sciences New York University, described here as one of the greatest living mathematicians and computer scientists, and who is interviewed here, in his book Engines of Logic: Mathematicians and the Origin of the Computer, in Chapter 8, page 181, here's how ENIAC worked:

An enormous machine, occupying a large room, and programmed by connecting cables to a plugboard rather like an old-fashioned telephone switchboard, the ENIAC was modeled on the most successful computing machines then available -- differential analyzers. Differential analyzers were not digital devices operating on numbers digit by digit. Rather numbers were represented by physical quantities that could be measured (like electric currents or voltages) and components were linked together to emulate the desired mathematical operations. These analog machines were limited in their accuracy by that of the instruments used for measurements. The ENIAC was a digital device, the first electronic machine able to deal with the same kind of mathematical problems as differential analyzers. Its designers built it of components functionally similar to those in differential analyzers, relying on the capacity of vacuum-tube electronics for greater speed and accuracy.

What is a Differential Analyzer?

Here is an explanation, complete with photographs at the link:

There are two distinct branches of the computer family. One branch descends from the abacus, which is an extension of finger counting. The devices that stem from the abacus use digits to express numbers, and are called digital computers. These include calculators and electronic digital computers.

The other branch descends from the graphic solution of problems achieved by ancient surveyors. Analogies were assumed between the boundaries of a property and lines drawn on paper by the surveyor. The term "analogue" is derived from the Greek "analogikos" meaning by proportion. There have been many analogue devices down the ages, such as the nomogram, planimeter, integraph and slide rule. These devices usually perform one function only. When an analogue device can be "programmed" in some way to perform different functions at different times, it can be called an analogue computer. The Differential Analyser is such a computer as it can be set up in different configurations, i.e. "programmed", to suit a particular problem.

In an analogue computer the process of calculation is replaced by the measurement and manipulation of some continuous physical quantity such as mechanical displacement or voltage, hence such devices are also called continuous computers. The analogue computer is a powerful tool for the modelling and investigation of dynamic systems, i.e. those in which some aspect of the system changes with time. Equations can be set up concerned with the rates of change of problem variables, e.g. velocity versus time. These equations are called Differential Equations, and they constitute the mathematical model of a dynamic system.

The previous explanation spelled out the differences between a digital computer and an analog computer. But what is the unique characteristic of a digital computer? The Stanford Encyclopedia of Philosophy's The Modern History of Computing describes the programming of a universal Turing machine as the manipulation of symbols stored in readable and writable memory:

In 1936, at Cambridge University, Turing invented the principle of the modern computer. He described an abstract digital computing machine consisting of a limitless memory and a scanner that moves back and forth through the memory, symbol by symbol, reading what it finds and writing further symbols (Turing [1936]). The actions of the scanner are dictated by a program of instructions that is stored in the memory in the form of symbols. This is Turing's stored-program concept, and implicit in it is the possibility of the machine operating on and modifying its own program.

The ENIAC was manipulating current and voltages to perform the calculation in the manner of a differential analyzer. But symbols are different. They are the 0s and 1s called bits. They are like letters written on paper. You don't measure them. You recognize them and manipulate them with precisely defined operations. This is a fundamental insight that the program is data. It is what makes it possible to have operating systems and programming languages because when program is data, you can have programs that manipulate or generate other programs.

Martin Davis, in the same book previously quoted, on page 185, explains the role of symbols:

It is well understood that the computers developed after Wold War II differed in a fundamental way from earlier automatic calculators. But the nature of the difference has been less well understood. These post-war machines were designed to be all-purpose universal devices capable of carrying out any symbolic process, so long as the step of the process were specified precisely. Some processes may require more memory than is available or may be too slow to be feasible, so these machines can only be approximations to Turing's idealized universal machine. Nevertheless it was crucial that they had a large memory (corresponding to Turing's infinite tape) in which instructions and data could coexist. This fluid boundary between what was instruction and what was data meant that programs could be developed that treated other programs as data. In early years, programmers mainly used this freedom to produce programs that could and did modify themselves. In today's world of operating systems and hierarchies of programming languages, the way has been opened to far more sophisticated applications. To an operating system, the programs that it launches (e.g. your word processor or email program) are data for it to manipulate, providing each program with its own part of the memory and (when multitasking) keeping track of the tasks each needs carried out. Compilers translate programs written in one of today's popular programming languages into the underlying instructions that can be directly executed by the computer: for the compiler these programs are data.

Does This Mean That It Is Possible for Computer Algorithms to be Generated by Programs as Opposed to Being Written by Humans?

Absolutely. For example, consider the language SQL that is used to access information stored in a relational database. We can write in SQL something like:

select name from presidents where birthdate

This statement may be used to retrieve the names of all presidents whose date of birth is prior to January 1, 1800, assuming the database contains such information. But the language SQL doesn't specify the algorithm to use to do so. The language is free to use the algorithm of its choice. The language may read all presidents in the database one by one, test their birth date and print those that pass the test. Or the language may as well read an index of the presidents that lists the presidents in the order of their birth date and print only the first president in the list until it find one born past January 1, 1800. Which algorithm is best will depend on how the database has been structured, and the choice is left to the language discretion.

Why Does a Program Require Setting Transistors on a Modern Computer?

This is because the RAM memory of modern computers where the program symbols are stored is made of transistors. They are required only to the extent the symbols will not be remembered by the computer if the transistors are not set. If the computer memory is not made of transistors, a program can be loaded in memory without setting any transistors. This was the case with some early models of computers, as is reported by Martin Davis, in the same book, on page 186:

In the late 1940s, two devices offered themselves as candidates for use as computer memory: the mercury delay line and the cathode ray tube. The delay line consisted of a tube of liquid mercury; data was stored in the form of an acoustic wave in the mercury bouncing back and forth from one end of the tube to another. Cathode ray tubes are familiar nowadays in TVs and computer monitors. Data could be stored as a pattern on the surface of the tube.

Why Does the Amicus Brief Argue That the Setting of Transistors is Relevant to Patentability of Software?

It is because they argue that it makes software similar or comparable to some industrial-age patentable devices. From the brief pp. 14-17:

In this respect, modern computer-related inventions are no different from other patent-eligible innovations that have produced a new and useful result by employing physical structures and phenomena to record, manipulate, or disseminate information.

Perhaps the most celebrated example of such technological innovation is Samuel Morse's invention of the electric telegraph, which (like modern computers) employed binary encoding in conjunction with the sequential operation of switches. Although petitioners focus almost exclusively on the Court's rejection of his eighth claim (on which more below), the Court allowed a number of other claims, including the fifth. O'Reilly v. Morse, 56 U.S. 62, 112 (1854). That claim was for "the system of signs, consisting of dots and spaces, and of dots, spaces and horizontal lines." Id. at 86. This system, an early version of Morse Code, was nothing other than a system for manipulating an on-off switch -- the telegraph key in a prescribed manner to produce the useful result of intelligible communications between two parties. Indeed, although much less complex, the telegraph system -- a web of interconnected switches spreading around the globe, enabling binary-encoded communication -- was comparable to the modern Internet.

The Industrial Age also knew software and hardware in a literal sense; the core concepts in computer design and programming were developed in this period. The principle of encoded instructions controlling a device found application at the opening of the Nineteenth Century, with the famous Jacquard loom, a device (still in use today) that adjusts the warp and weft of a textile in response to "programming" contained on punch cards. The loom's control apparatus consists of a series of on-off switches which are controlled by the pattern of holes punched in the cards, just as the pattern of microscopic pits and lands on the surface of a CD can be used to control the transistor switches inside a computer. Hyman, supra, at 166; Patterson & Hennessy, supra, at 24.

Inventors soon seized on the "programming" principle applied in the Jacquard loom. A defining characteristic of Babbage's Analytical Engine, for example, was the use of punch cards, adopted from the Jacquard loom, to store the programs run by the machine. "Following the introduction of punched cards early in 1836 four functional units familiar in the modern computer could soon be clearly distinguished: input/output system, mill, store, and control." Hyman, supra, at 166. Babbage's close friend, Ada Lovelace (the daughter of Lord Byron), is now recognized as "the first computer programmer" for her work developing software programs for the Analytical Engine. Nell Dale et al., Programming and Problem Solving with C++, 406-407 (1997).

Later in the Nineteenth Century, Herman Hollerith, a U.S. Census Office employee, developed a means of tabulating census results using punch cards and mechanical calculation. His method allowed the country to complete the 1890 census two years sooner and for five million dollars less than manual tabulation. William R. Aul, "Herman Hollerith: Data Processing Pioneer," Think, 22-23 (Nov. 1972). The company he founded became the International Business Machines Corp., and the once-prevalent IBM punch-cards were both the direct descendent of the means used to program a Jacquard loom and the immediate predecessor to today's CDs and other media, which contain digitized instructions for modern computers to open and close millions of switches.

As has been often noted by historians of technological development, our perceptions of innovation and modernity are often misguided -- the roots of technological change are deep, and run farther back in our history than we perceive. See Brian Winston, Media Technology & Society: A History 1 (1998) (arguing that current innovations in communications technology are "hyperbolised as a revolutionary train of events [but] can be seen as a far more evolutionary and less transforming process"). That is certainly true with respect to computer-related inventions.

While the hardware and software implemented by a modern e-mail program may be orders of magnitude more complex than the dot-dash-dot of a telegraph key, the underlying physical activity that makes communication possible -- the sequential operation of switches -- is fundamentally the same.

Are Modern Computer Really Similar to These Industrial Age Device?

No, because none of these devices implements the principle of a universal Turing machine. For example Andrew Hodges, a well-known Alan Turing historian and maintainer of the Alan Turing's home page, describes the difference between Babbage's analytical engine and computers as follows:

So I wouldn't call Charles Babbage's 1840s Analytical Engine the design for a computer. It didn't incorporate the vital idea which is now exploited by the computer in the modern sense, the idea of storing programs in the same form as data and intermediate working. His machine was designed to store programs on cards, while the working was to be done by mechanical cogs and wheels.

The Jacquard loom, a machine that could weave cloth with a pattern specified by a stack of punched cards, revolutionized weaving practice first in France and eventually all over the world. With perhaps understandable hyperbole, it is commonly said among professional weavers that this was the first computer. Although it is a wonderful invention, the Jacquard loom was no more of a computer than is a player piano. Like a piano it permits a mechanical device to be controlled automatically by the presence or absence of punched holes in an input medium.