History of Computers

The first electronic digital computer was called "ENIAC" built in 1945 in Philadelphia. It used so much electricity that lights in the nearby town dimmed every time it was used! What a long way we have come in a half-century, with personal computers in homes, offices, and schoolrooms across the world. After the arrival of the microprocessor, many different computer companies appeared and began developing their own microprocessors and microcomputers. Companies such as Apple, Compaq, and Commodore started during this period of confusion. At the conclusion of the timeline is the first home personal computer or PC, by IBM in 1981. Computers began to steadily and rapidly increase in speed and power while becoming more compact and more user friendly from the early 1980's on. The progress, however came in many small steps, rather than fewer major events like earlier years. From the start of the decade to today, PCs in the home have become immensely popular. Computers have increased their role from professional and business machines to entertainment and educational tools. Telecommunications advancements such as the Internet have shown themselves to be useful both in education and business. Hard disks or Computer hardware were invented in the 1950s. They started as large disks up to 20 inches in diameter holding just a few megabytes. They were originally called "fixed disks" or "Winchesters" (a code name used for a popular IBM product). They later became known as "hard disks" to distinguish them from "floppy disks." Hard disks have a hard platter that holds the magnetic medium, as opposed to the flexible plastic film found in tapes and floppies. At the simplest level, a hard disk is not that different from a cassette tape. Both hard disks and cassette tapes use the same magnetic recording techniques. A typical desktop machine will have a hard disk with a capacity of between 10 and 40 gigabytes. Data is stored onto the disk in the form of files. A file is simply a named collection of bytes. The bytes might be the ASCII codes for the characters of a text file, or they could be the instructions of a software application for the computer to execute, or they could be the records of a data base, or they could be the pixel colors for a GIF image. No matter what it contains, however, a file is simply a string of bytes. When a program running on the computer requests a file, the hard disk retrieves its bytes and sends them to the CPU one at a time. The Internet was the result of some visionary thinking by people in the early 1960s who saw great potential value in allowing computers to share information on research and development in scientific and military fields. The Internet, then known as ARPANET, was brought online in 1969 under a contract let by the renamed Advanced Research Projects Agency (ARPA) which initially connected four major computers at universities in the southwestern US. The Internet was designed in part to provide a communications network that would work even if some of the sites were destroyed by nuclear attack. The early Internet was used by computer experts, engineers, scientists, and librarians. E-mail was adapted for ARPANET by Ray Tomlinson of BBN in 1972. He picked the @ symbol from the available symbols on his teletype to link the username and address. As the commands for e-mail, FTP, and telnet were standardized, it became a lot easier for non-technical people to learn to use the nets. Most Internet Service Providers or( ISP’s ) make use of these protocols in E-mail, Usenet newsgroups, file sharing, the World Wide Web, Gopher, session access, WAIS, finger, IRC, Mud’s, and Mush’s. Of these, e-mail and the World Wide Web are clearly the most used, and many other services are built upon them, such as mailing lists and web logs. The Internet makes it possible to provide real-time services such as web radio and web casts that can be accessed from anywhere in the world. The Internet is also having a profound impact on knowledge and worldviews. Through keyword-driven Internet research, using search engines, millions worldwide have easy, instant access to a vast amount and diversity of online information. Compared to encyclopedias and traditional libraries, the Internet represents a sudden and extreme decentralization of information and data. A current trend with major implications for the future is the growth of high speed connections. 56K dialup modems are not fast enough to carry multimedia, such as sound and video except in low quality. But new technologies many times faster, such as cable modems, digital subscriber lines (DSL), and satellite broadcast are widely available now, and growing fast. The rapid growth of local networks, even in homes, has increased the demand. Common methods of home access include dial-up, broadband and satellite communications. As the commands for e-mail, FTP, and telnet were standardized, it became a lot easier for non-technical people to learn to use the nets. It was not easy by today's standards by any means, but it did open up use of the Internet to many more people in universities in particular. Other departments besides the libraries, computer, physics, and engineering departments found ways to make good use of the nets--to communicate with colleagues around the world and to share files and resources. We have come a long way in computer technology since the ENIAC. Now eighty percent of American households have at least one computer, and most households have one computer exclusively for the use of PC games, music, videos, and surfing the web.