---
title: "History of computer science"
chunk: 4/5
source: "https://en.wikipedia.org/wiki/History_of_computer_science"
category: "reference"
tags: "science, encyclopedia"
date_saved: "2026-05-05T03:59:29.311655+00:00"
instance: "kb-cron"
---

In 1941, Konrad Zuse developed the world's first functional program-controlled computer, the Z3. In 1998, it was shown to be Turing-complete in principle. Zuse also developed the S2 computing machine, considered the first process control computer. He founded one of the earliest computer businesses in 1941, producing the Z4, which became the world's first commercial computer.  In 1946, he designed the first high-level programming language, Plankalkül.
In 1948, the Manchester Baby was completed; it was the world's first electronic digital computer that ran programs stored in its memory, like almost all modern computers. The influence on Max Newman of Turing's seminal 1936 paper on the Turing Machines and of his logico-mathematical contributions to the project, were both crucial to the successful development of the Baby.
In 1950, Britain's National Physical Laboratory completed Pilot ACE, a small scale programmable computer, based on Turing's philosophy. With an operating speed of 1 MHz, the Pilot Model ACE was for some time the fastest computer in the world. Turing's design for ACE had much in common with today's RISC architectures and it called for a high-speed memory of roughly the same capacity as an early Macintosh computer, which was enormous by the standards of his day. Had Turing's ACE been built as planned and in full, it would have been in a different league from the other early computers.
Later in the 1950s, the first operating system, GM-NAA I/O, supporting batch processing to allow jobs to be run with less operator intervention, was developed by General Motors and North American Aviation for the IBM 701.
In 1969, an experiment was conducted by two research teams at UCLA and Stanford to create a network between 2 computers although the system crashed during the initial attempt to connect to the other computer but was a huge step towards the Internet.

The first actual computer bug was a moth. It was stuck in between the relays on the Harvard Mark II.
While the invention of the term 'bug' is often but erroneously attributed to Grace Hopper, a future rear admiral in the U.S. Navy, who supposedly logged the "bug" on September 9, 1945, most other accounts conflict at least with these details. According to these accounts, the actual date was September 9, 1947 when operators filed this 'incident' — along with the insect and the notation "First actual case of bug being found" (see software bug for details).

=== Shannon and information theory ===
Claude Shannon went on to found the field of information theory with his 1948 paper titled A Mathematical Theory of Communication, which applied probability theory to the problem of how to best encode the information a sender wants to transmit.  This work is one of the theoretical foundations for many areas of study, including data compression and cryptography.

=== Wiener and cybernetics ===
From experiments with anti-aircraft systems that interpreted radar images to detect enemy planes, Norbert Wiener coined the term cybernetics from the Greek word for "steersman." He published "Cybernetics" in 1948, which influenced artificial intelligence. Wiener also compared computation, computing machinery, memory devices, and other cognitive similarities with his analysis of brain waves.

=== John von Neumann and the von Neumann architecture ===

In 1946, a model for computer architecture was introduced and became known as Von Neumann architecture. Since 1950, the von Neumann model provided uniformity in subsequent computer designs. The von Neumann architecture was considered innovative as it introduced an idea of allowing machine instructions and data to share memory space. The von Neumann model is composed of three major parts, the arithmetic logic unit (ALU), the memory, and the instruction processing unit (IPU). In von Neumann machine design, the IPU passes addresses to memory, and memory, in turn, is routed either back to the IPU if an instruction is being fetched or to the ALU if data is being fetched.
Von Neumann's machine design uses a RISC (Reduced instruction set computing) architecture, which means the instruction set uses a total of 21 instructions to perform all tasks. (This is in contrast to CISC, complex instruction set computing, instruction sets which have more instructions from which to choose.)  With von Neumann architecture, main memory along with the accumulator (the register that holds the result of logical operations) are the two memories that are addressed. Operations can be carried out as simple arithmetic (these are performed by the ALU and include addition, subtraction, multiplication and division), conditional branches (these are more commonly seen now as if statements or while loops. The branches serve as go to statements), and logical moves between the different components of the machine, i.e., a move from the accumulator to memory or vice versa. Von Neumann architecture accepts fractions and instructions as data types. Finally, as the von Neumann architecture is a simple one, its register management is also simple. The architecture uses a set of seven registers to manipulate and interpret fetched data and instructions. These registers include the "IR" (instruction register), "IBR" (instruction buffer register), "MQ" (multiplier quotient register), "MAR" (memory address register), and "MDR" (memory data register)."  The architecture also uses a program counter ("PC") to keep track of where in the program the machine is.

=== John McCarthy, Marvin Minsky and artificial intelligence ===