1、1. First Computers Were PeopleComputer was originally a job title: it was used to describe those human beings (predominantly women) whose job it was to perform the repetitive calculations required to compute such things as navigational tables, tide charts, and planetary positions for astronomical al
2、manacs. The abacus was an early aid for mathematical computations. A very old abacus A more modern abacus Napiers invention led directly to the slide rule (shown in Fig.16-3), first built in England in 1632 and was still in use in the 1960s by the NASA engineers of the Mercury, Gemini, and Apollo pr
3、ograms which landed men on the moon. The title of forefather of todays all-electronic digital computers is usually awarded to ENIAC, (Electronic Numerical Integrator and Calculator). Two views of ENIAC: the Electronic Numerical Integrator and Calculator If you learned computer programming in the 197
4、0s, you dealt with what today are called mainframe computers, such as the IBM 7090 (As is shown in Fig.16-5), IBM 360, or IBM 370. A teletype was a motorized typewriter that could transmit your keystrokes to the mainframe and then print the computers response on its roll of paper. The first personal
5、 computers, introduced in 1975, came as kits：The MITS Altair 8800, followed by the IMSAI 8080, an Altair clone. The young industry exploded in 1977 as Apple introduced the Apple II, a color computer with expansion slots and floppy drive support.Software took center stage in 1978 when Dan Bricklin an
6、d Bob Frankston produced VisiCalc, the first spread sheet. This turned the personal computer into a useful business tool, not just a game machine or replacement for the electric typewriter. The Shuguang 4000A (shown in Fig.16-8) at the Shanghai Supercomputing Center (shown in Fig.16-9) comes to the
7、next, for calculating 11 trillion times per second. 2. Computers Hardware If you get the opportunity, try to identify the various parts mentioned in these pages with those on the computer you are using and it will all begin to make more sense. . Input Devices2）If you need to transfer images into the
8、 computer you can use a scanner that acts like a photocopier for the computer. 3) If you need to draw images and have them displayed on the computer screen you can use the mouse, but this is often compared to attempting to use a brick to draw with. 4) Games players have a wide range of hardware avai
9、lable to them to help them drive, fly, score, and shoot more realistically than by using a mouse . Output DevicesOnce the user has managed to input the commands and information required into the computer, there are several output devices for the computer to pass that information back to the user. Th
10、e most obvious is the computer monitor, sometimes known as a VDU or visual display unit. One of the most important output devices to add to any computer system is a printer . Set of Computer The PC may be the single most important tool for many workers, but because it is often purchased in a high st
11、reet camera store or even a supermarket, it is often treated as a commodity item, almost a white good such as a fridge, freezer or microwave. No technical background is assumed, and even very complex issues will be explained in terms that everyone can understand 1) Your computer was really made by c
12、ompanies such as Asus, Abit, ATI, and AMD. The CPU chip is the largest chip inside the computer and all data passes to it and through it to all the other components such as memory and hard drives. However, the collection of standard “legacy” connectors in the back of every computer has now become ob
13、solete. Instead of PS2, serial and parallel ports, the keyboard, mouse, printers, and scanners can all be connected to a computer through the new standard, smaller, and more flexible USB ports. Unfortunately, consumers still expect the old connectors to be present 2) The motherboard is at the heart
14、of the computer. 3) A hard disk stores all your data and programs 4) The PCI bus (slots) was introduced by Intel about ten years ago and is still in use today. 5) Memory is just as important to computers as it is to us. Memory chips store all the information used by the computer to carry out a task
15、6) Video cards plug into an AGP slot. They are responsible for processing the colour and images that appear on the screen of your monitor Although ever increasing, speed is becoming irrelevant to most users. Almost all current computers are easily fast enough to run Windows, browse the Web, read E-M
16、ail, listen to MP3 (music) files, and run all the Office programs. Faster speeds are only useful if you play computer games, edit video files, or run a server. 3. Operating System.IntroductionAn operating system (OS), in computer science, is the basic software that controls a computer. It has three
17、major functions: it coordinates and manipulates computer hardware, such as computer memory, printers, disks, keyboard, mouse, and monitor; it organizes files on a variety of storage media, such as floppy disk, hard drive, compact disc, digital video disc, and tape; and it manages hardware errors and
18、 the loss of data operating system services . History of Operating SystemHistory of operating system was started with the first generation computers. The early operating systems were diverse, with each vendor producing their own operating systems specific to their hardware. This continued until the
19、1960s when IBM developed the S/360 series of machines, where all machines ran the same operating system, OS/360. OS/2 was the first operating system to provide intrinsic multitasking based on hardware support. 1) How an Operating System WorksOperating systems control different computer processes, su
20、ch as running a spreadsheet program or accessing information from the computers memory. One important process is interpreting commands, enabling the user to communicate with the computer. 2) Main Categories of Operating SystemsOne operating system might be better suited to some computing tasks than
21、others. To provide clues to their strengths and weaknesses, operating systems are informally categorized and characterized using one or more of the following terms:A single-user operating system A multiuser operating system A network operating system A multitasking operating system A desktop operati
22、ng system 3) Future TechnologiesOperating systems continue to evolve. For instance, research is being conducted that would replace the keyboard with a means of using voice or handwriting for input. Currently these types of input are imprecise because people pronounce and write words very differently
23、, making it difficult for a computer to recognize the same input from different users. However, advances in this field have led to systems that can recognize a small number of words spoken by a variety of people. In addition, software has been developed that can be taught to recognize an individuals
24、 handwriting. Windows XP Operating SystemWindows XP is an example of an operating system. It uses graphics Microsoft Windows XP (pictures) to connect you to the computers hardware and software in an easy-to-understand (hopefully!) way . Microsoft Windows XP also comes with many free, built-in progra
25、ms that can help you create documents, movies and images, calculate figures, enjoy some music, browse the Internet, or play a few games. Windows XP operating system service . Exploring the DesktopDesktop: Icons Start Button, and the Taskbar Notification Area desktop A Window is a rectangle on your s
26、creen that organizes how you view and work in specific programs or view files on your computer You can find the Start Button in the corner of your screen. Just like the name suggests, this is an excellent place to start your work. When you click on the Start Button, a special list called the Start M
27、enu appears. 4. Basic Computer Network A network is a collection of individual networks, connected by intermediate networking devices, that functions as a single large network. Networking refers to the industry, products, and procedures that meet the challenge of creating and administering networks.
28、 different network technologies can be connected to create a network . Internet The Internet is as much a collection of communities as a collection of technologies, and its success is largely attributable to both satisfying basic community needs as well as utilizing the community in an effective way
29、 to push the infrastructure forward. This community spirit has a long history beginning with the early ARPANET. In the autumn of 1969 the first ARPANET computer was connected to the ARPANETs IMP node at the University of California at Los Angeles (UCLA). During the 1970s, the ARPANET grew to connect
30、 research institutes and laboratories supported by the Department of Defense in various parts of the USA. Many of these were university laboratories studying data processing and computer networks, which developed the TCP/IP network and its applications for the internet.In 1980 IP became the official
31、 standard of the US Department of Defense, and the original ARPANET adopted IP on 1.1.1983, when it became a major part of the Internet. In 1983, when Barry Leiner took over management of the Internet research program at DARPA, he and Clark recognized that the continuing growth of the Internet commu
32、nity demanded a restructuring of the coordination mechanisms.In 1992, yet another reorganization took place. In 1992, the Internet Activities Board was re-organized and re-named the Internet Architecture Board operating under the auspices of the Internet Society. The recent development and widesprea
33、d deployment of the World Wide Web has brought with it a new community, as many of the people working on the WWW have not thought of themselves as primarily network researchers and developers. A new coordination organization was formed, the World Wide Web Consortium (W3C). . CERNETCERNET(Chinese Edu
34、cational Research Network) is Chinas first and largest national academic Internet backbone, and currently the second largest network backbone in China. CERNET is supported by the Chinese government and directly managed by the Ministry of Education. Its network infrastructure mainly serves the univer
35、sities, institutes, colleges and schools all over the China. The end users are professors, researchers and students. CERNET was established in 1994. It provides services for Chinese universities, institutes, schools and other non-profit organizations in China, including network connection, domain na
36、me and IP address assignment, and educational and research resources and super computing services. Since 1995, CERNET organizes member meetings annually, and also organized several large international conferences and workshops to promote its knowledge and share experiences and ideas. CERNET has been
37、 playing the most important role in the research of advanced network technologies and applications . CERNET Evolution1)Startup Stage (1994-1995) - CERNET Pilot Project (1994.7 1995.12) 2) 2) Growth (1996-1999) 3) 3) Status Quo and Future Evolution (2000 ) CERNET will cooperate with China Broadcast and Television Education System to improve the environment and conditions for higher education, compulsory education and adult education in China to serve to cultivation of culture-indifferent, future-oriented and modernization-oriented talents.
