Some believe that the technological limitations of the time were a further obstacle to the construction of the machine; others believe that the machine could have been built successfully with the technology of the era if funding and political support had been stronger. Charles Babbage was notoriously hard to work with and alienated a great number of people who had at first supported him, including his engineer Joseph Clement.
The analytical engine was to be powered by a steam engine and would have been over 30 metres long and 10 metres wide. The input (programs and data) was to be provided to the machine via punched cards, a method being used at the time to direct mechanical looms such as the Jacquard loom. For output, the machine would have a printer, a curve plotter and a bell. The machine would also be able to punch numbers onto cards to be read in later. It employed ordinary base-10 fixed-point arithmetic.
There was to be a store (i.e., a memory) capable of holding 1,000 numbers of 50 decimal digits each (ca. 20.7kB). An arithmetical unit (the "mill") would be able to perform all four arithmetic operations, plus comparisons and optionally square roots. Initially it was conceived as a difference engine curved back upon itself, in a generally circular layout, with the long store exiting off to one side. (Later drawings depict a regularized grid layout.) Like the central processing unit (CPU) in a modern computer, the mill would rely upon its own internal procedures, to be stored in the form of pegs inserted into rotating drums called "barrels," in order to carry out some of the more complex instructions the user's program might specify. (See microcode for the modern equivalent.)
The programming language to be employed by users was akin to modern day assembly languages. Loops and conditional branching were possible and so the language as conceived would have been Turing-complete long before Alan Turing's concept. Three different types of punch cards were used: one for arithmetical operations, one for numerical constants, and one for load and store operations, transferring numbers from the store to the arithmetical unit or back. There were three separate readers for the three types of cards.
In 1842, the Italian mathematician Luigi Menabrea, whom Babbage had met while travelling in Italy, wrote a description of the engine in French. In 1843, the description was translated into English and extensively annotated by Ada King, Countess of Lovelace, who had become interested in the engine ten years earlier. In recognition of her additions to Menabrea's paper, which included a way to calculate Bernoulli numbers using the machine, she has been described as the first computer programmer. The modern computer programming language Ada is named in her honour.
In 1910, Babbage's son Henry P. Babbage reported that a part of the mill and the printing apparatus had been constructed and had been used to calculate a (faulty) list of multiples of pi. This constituted only a small part of the whole engine; it was not programmable and had no storage. (Popular images of this section have sometimes been mislabelled, implying that it was the entire mill or even the entire engine.)
Henry also proposed building a demonstration version of the full engine, with a smaller storage capacity: "perhaps for a first machine ten[columns] would do, with fifteen wheels in each". Such a version could manipulate 20 numbers of 25 digits each, and what it could be told to do with those numbers could still be impressive. "It is only a question of cards and time," wrote Henry Babbage in 1888, "...and there is no reason why [twenty thousand] cards should not be used if necessary, in an Analytical Engine for the purposes of the mathematician."
Closely related to Babbage's work on the analytical engine was the work of George Stibitz of Bell Laboratories in New York just prior to WWII, as well as Howard Hathaway Aiken at Harvard University during and just after WWII. They both built electromechanical (i.e. relay-and-switch) computers which were closely related to the analytical engine, though neither was quite a modern programmable computer. Aiken's machine was largely financed by IBM and was called the Harvard Mark I. Aiken was inspired by a piece of the Analytical engine deposited at the university by Henry Babbage in 1886, and discovered by him in the 1930s. He gained access to Babbage's writings and later claimed, pointing to Babbage's books:
In molecular nanotechnology, the earliest proposal for a way to implement extremely small and fast computers relied upon logic gates constructed from sliding rods and stubby protrusions to conditionally restrict their motion. Similar computational "rod-logic" was present in the sliding control levers and studded barrel devices which were used to access the microprogram in Babbage's design.
In May, Agilent gained access to BIA Separations GmbH's bio-monolithic technology.(Liquid Chromatography: Company Announcements)
Jun 15, 2008; In May, Agilent gained access to BIA Separations GmbH's bio-monolithic technology. Agilent plans to commercialize columns with...
Bray knife killer Shane Clancy gained access to the home of his victims by knocking on the front door, survivors of the attack have told gardai.
Aug 26, 2009; Knife killer was let into house after knocking on the door Bray knife killer Shane Clancy gained access to the home of his...