When was the first computer invented?

There is no easy answer to this question due to the many different classifications ofcomputers. The first mechanical computer, created by Charles Babbage in 1822, doesn't really resemble what most would consider a computer today. Therefore, this document has been created with a listing of each of the computer firsts, starting with the Difference Engine and leading up to the computers we use today.

Note: Early inventions which helped lead up to the computer, such as the abacus,calculator, and tablet machines, are not accounted for in this document.

The word "computer" was first used

The word "computer" was first recorded as being used in 1613 and originally was used to describe a human who performed calculations or computations. The definition of a computer remained the same until the end of the 19th century, when the industrial revolution gave rise to machines whose primary purpose was calculating.

First mechanical computer or automatic computing engine concept

In 1822, Charles Babbage conceptualized and began developing the Difference Engine, considered to be the first automatic computing machine. The Difference Engine was capable of computing several sets of numbers and making hard copies of the results. Babbage received some help with development of the Difference Engine from Ada Lovelace, considered by many to be the first computer programmer for her work and notes on the Difference Engine. Unfortunately, because of funding, Babbage was never able to complete a full-scale functional version of this machine. In June of 1991, the London Science Museum completed the Difference Engine No 2 for the bicentennial year of Babbage's birth and later completed the printing mechanism in 2000.

In 1837, Charles Babbage proposed the first general mechanical computer, the Analytical Engine. The Analytical Engine contained an Arithmetic Logic Unit (ALU), basic flow control, and integrated memory and is the first general-purpose computer concept. Unfortunately, because of funding issues, this computer was also never built while Charles Babbage was alive. In 1910, Henry Babbage, Charles Babbage's youngest son, was able to complete a portion of this machine and was able to perform basic calculations.

First programmable computer

The Z1 was created by German Konrad Zuse in his parents' living room between 1936and 1938. It is considered to be the first electro-mechanical binary programmable computer, and the first really functional modern computer.

First concepts of what we consider a modern computer

The Turing machine was first proposed by Alan Turing in 1936 and became the foundation for theories about computing and computers. The machine was a device that printed symbols on paper tape in a manner that emulated a person following a series of logical instructions. Without these fundamentals, we wouldn't have the computers we use today.

The first electric programmable computer

The Colossus was the first electric programmable computer, developed by Tommy Flowers, and first demonstrated in December1943. The Colossus was created to help the British code breakers read encrypted German messages.

The first digital computer

Short for Atanasoff-Berry Computer, theABC began development by Professor John Vincent Atanasoff and graduate student Cliff Berry in 1937. Its development continued until 1942 at the Iowa State College (now Iowa State University).

The ABC was an electrical computer that used vacuum tubes for digital computation, including binary math and Boolean logic and had no CPU. On October 19, 1973, the US Federal Judge Earl R. Larson signed his decision that the ENIAC patent by J. Presper Eckert and John Mauchly was invalid and named Atanasoff the inventor of the electronic digital computer.

The ENIAC was invented by J. Presper Eckert and John Mauchly at the University of Pennsylvania and began construction in 1943 and was not completed until 1946. It occupied about 1,800 square feet and used about 18,000 vacuum tubes, weighing almost 50 tons. Although the Judge ruled that the ABC computer was the first digital computer, many still consider the ENIAC to be the first digital computer because it was fully functional.

The first stored program computer

The early British computer known as the EDSAC is considered to be the first stored program electronic computer. The computer performed its first calculation on May 6,1949 and was the computer that ran the first graphical computer game, nicknamed "Baby".

      

Around the same time, the Manchester Mark 1 was another computer that could run stored programs. Built at the Victoria University of Manchester, the first version of the Mark 1 computer became operational in April 1949.  Mark 1 was used to run a program to search for Mersenne primes for nine hours without error on June 16 and 17 that same year.

The first computer company

The first computer company was the Electronic Controls Company and was founded in1949 by J. Presper Eckert and John Mauchly, the same individuals who helped create the ENIAC computer. The company was later renamed to EMCC or Eckert-Mauchly Computer Corporation and released a series of mainframe computers under the UNIVAC name.

First stored program computer

First delivered to the United States government in 1950, theUNIVAC 1101 or ERA 1101 is considered to be the first computer that was capable of storing and running a program from memory.

First commercial computer

In 1942, Konrad Zuse begin working on the Z4 that later became the first commercial computer. The computer was sold to Eduard Stiefel, a mathematician of the Swiss Federal Institute of Technology Zurich on July 12, 1950.

IBM's first computer

On April 7, 1953 IBM publicly introduced the 701; its first commercial scientific computer.

The first computer with RAM

MIT introduces the Whirlwind machine on March 8, 1955, a revolutionary computer that was the first digital computer with magnetic core RAM and real-time graphics.

The first transistor computer

The TX-O (Transistorized Experimental computer) is the first transistorized computer to be demonstrated at the Massachusetts Institute of Technology in1956.

The first minicomputer

In 1960, Digital Equipment Corporation released its first of many PDP computers, the PDP-1.

The first desktop and mass-market computer

In 1964, the first desktop computer, the Programma 101, was unveiled to the public at the New York World's Fair. It was invented by Pier Giorgio Perotto and manufactured by Olivetti. About 44,000 Programma 101 computers were sold, each with a price tag of $3,200.

In 1968, Hewlett Packard began marketing the HP 9100A, considered to be the first mass-marketed desktop computer.

The first workstation

Although it was never sold, the first workstation is considered to be the Xerox Alto, introduced in 1974. The computer was revolutionary for its time and included a fully functional computer, display, and mouse. The computer operated like many computers today utilizing windows, menus and icons as an interface to its operating system. Many of the computer's capabilities were first demonstrated in The Mother of All Demos byDouglas Engelbart on December 9, 1968.

The first microprocessor

Intel introduces the first microprocessor, the Intel 4004 on November 15, 1971.

The first micro-computer

The Vietnamese-French engineer, André Truong Trong Thi, along with Francois Gernelle, developed the Micral computer in 1973. Considered as the first "micro-computer", it used the Intel 8008 processor and was the first commercial non-assembly computer. It originally sold for $1,750.

The first personal computer

In 1975, Ed Roberts coined the term "personal computer" when he introduced the Altair8800. Although the first personal computer is considered by many to be the KENBAK-1, which was first introduced for $750 in 1971. The computer relied on a series of switches for inputting data and output data by turning on and off a series of lights.

The first laptop or portable computer

The IBM 5100 is the first portable computer, which was released on September 1975. The computer weighed 55 pounds and had a five inch CRT display, tape drive, 1.9MHz PALM processor, and 64KB of RAM. In the picture is an ad of the IBM 5100 taken from a November 1975 issue of Scientific America.

The first truly portable computer or laptop is considered to be the Osborne I, which was released on April 1981 and developed by Adam Osborne. The Osborne I weighed 24.5 pounds, had a 5-inch display, 64 KB of memory, two 5 1/4" floppy drives, ran theCP/M 2.2 operating system, included a modem, and cost US$1,795.

The IBM PC Division (PCD) later released the IBM portable in 1984, it's first portable computer that weighed in at 30 pounds. Later in 1986, IBM PCD announced it's firstlaptop computer, the PC Convertible, weighing 12 pounds. Finally, in 1994, IBM introduced the IBM ThinkPad 775CD, the first notebook with an integrated CD-ROM.

The first Apple computer

The Apple I (Apple 1) was the first Apple computer that originally sold for $666.66. The computer kit was developed by Steve Wozniak in 1976 and contained a 6502 8-bit processor and 4 kb of memory, which was expandable to 8 or 48 kb using expansion cards. Although the Apple I had a fully assembled circuit board the kit still required apower supply, display, keyboard, and case to be operational. Below is a picture of an Apple I from an advertisement by Apple.

The first IBM personal computer

IBM introduced its first personal computer called the IBM PC in 1981. The computer was code named and still sometimes referred to as the Acorn and had a 8088processor, 16 KB of memory, which was expandable to 256 and utilized MS-DOS.

The first PC clone

The Compaq Portable is considered to be the first PC clone and was release in March 1983 by Compaq. The Compaq Portable was 100% compatible with IBM computers and was capable of running any software developed for IBM computers.

• See the below other computer companies first for other IBM compatible computers

The first multimedia computer

In 1992, Tandy Radio Shack became one of the first companies to release a computer based on the MPC standard with its introduction of the M2500 XL/2 and M4020 SX computers.

Other computer company firsts

Below is a listing of some of the major computers companies first computers.

Commodore - In 1977, Commodore introduced its first computer, the "Commodore PET".
Compaq - In March 1983, Compaq released its first computer and the first 100% IBM compatible computer, the "Compaq Portable."
Dell - In 1985, Dell introduced its first computer, the "Turbo PC."
Hewlett Packard - In 1966, Hewlett Packard released its first general computer, the "HP-2115."
NEC - In 1958, NEC builds its first computer, the "NEAC 1101."
Toshiba - In 1954, Toshiba introduces its first computer, the "TAC" digital computer.