A succession of steadily more powerful and flexible computing devices, broadly, a term describing any goal-oriented activity requiring, benefiting from, or creating computers, were constructed in the 1930s and 1940s, gradually adding the key features that are seen in modern computers. The use of digital electronics (largely invented by Claude Shannon, an American mathematician, electronic engineer, and cartographer known as “The father of Information Theory,” in 1937) and more flexible programmability were vitally important steps, but defining one point along this road as “the first digital electronic computer” is difficult. Notable achievements include:
- Electrochemical “Z machines,” by Konrad Zuse, a German civil engineer, inventor and computer pioneer. The Z3 (1941) was the first working machine featuring binary arithmetic–the “binary numeral system,” or “base-2 number system,” represents numeric values using two symbols: 0 and 1–including floating point arithmetic and a measure of programmability. In 1998, the Z3 was proved to be Turing complete (“computationally universal”), which in computability theory, a system of data-manipulation rules (such as a computer’s instruction set, a programming language, or a acellular automation), is when it can be used to simulate any single-tape Turing machine; therefore being the world’s first operational computer.
- The non-programmable Atanasoff-Berry Computer, or “ABC” (commenced ion 1937, completed in 1941), which used vacuum tube based computation, or any type of calculation or use of computing technology in information processing; binary numbers; and regenerative capacitor memory, a type of computer memory that uses the electrical property of capacitance to store the bits of data. The use of regenerative memory allowed it to be much more compact than its peers (being approximately the size of a large desk or workbench), since intermediate results could be stored and then fed back into the same set of computation elements.
- The secret British Colossus computers (1943), the world’s first electronic, digital, fixed-program, single-purpose computer with variable coefficients, which had limited programmability but demonstrated that a device using thousands of tubes could be reasonably reliable and electronically reprogrammable. It was used for breaking German wartime codes; “Cryptanalysis” is the art and science of analyzing information systems in order to study the hidden aspects of the systems.
- The IBM Automatic Sequence Controlled Calculator (“ASCC”), called “Mark 1” (1944) by Harvard University, an large-scale electro-mechanical computer with limited programmability.
- The US Army’s’ Ballistic Research Laboratory (BRL), at Aberdeen Proving Ground, Maryland was the center for the United States Army’s research efforts in ballistics and vulnerability/lethality analysis. Their ENIAC (“Electronic Numerical Integrator And Computer”; 1946), the first electronic general-purpose computer, which used decimal arithmetic (also called “base ten” or occasionally “denary”), has ten as its base. It is sometimes called the first general purpose electronic computer, dealing with electrical circuits that involve active electrical components such as vacuum tubes, transistors, diodes and integrated circuits, and associated passive interconnection technologies; since Konrad Zuse’s Z3 of 1941 which used electromagnet, a type of magnet in which the magnetic field is produced by the flow of electric current, instead of electronics. Initially, however, ENIAC had an inflexible architecture which essentially required requiring to change its programming.