1. Understanding Computers

2. Objectives Explain how input devices are suited to certain
kinds of data
Distinguish between RAM and ROM
Identify an appropriate output devices for
different types of data
Explain the binary system used by computers
Describe how software is written and translated

3. Objectives Summarize the tasks of operating systems
Identity two leading operating systems and
explain why compatibility is an issue
Compare and contrast different kinds of
computers used in organization
computers used by individuals

4. Key Terms Command Computer System Flash Drives
Handwriting-Recognition Software
Motherboard
Read-Only Memory (ROM)
Speech-Recognition Software
ASCII
Compiler

5. Key Terms Interpreter Programmer Source Code Desktop Computer
Handheld Computer
Mainframe
Netbook
Server
Super Computer
Tablet Computer

6. Introduction
Computers come in many different shapes and sizes. Some are large enough to fill a room. Others can be held in the palm of your hand. Whatever their size and capabilities, all these computer have something in common. They use electronic parts and instructions to perform specific tasks.

7. Exploring Computer Systems
Parts Make a Whole – It takes many different parts working together for a computer to do its job. A computer system includes several devices that perform the four basic functions of computing input, processing, output, and storage. Input Devices – Input means entering data, such as text, images, or sounds. Computer user can choose from several different input devices designed to work with different forms of data.

8. Input Device (continued)
Graphics Card (Major Part) Graphics cards, video cards or video adapters and they're responsible for putting the image generated by the computer onto a monitor. The display can be in a number of resolutions such as 800 x 600, 1024 x 768 or 1280 x The greater the resolution and the more colors the card displays.

9. Input Device (continued)
Sound Card (Major Part) Microphones can be used to input sounds. As with images, sounds stored on a storage device or on the Internet can also be brought into the computer as input.

10. Processing Devices
Motherboard (Major Part) The name says it all - the Mother is the Heart of the PC. This is the large printed circuit board you'll see in the case which houses the main\ components of the computer. It has slots for plugging-in memory and, probably I/O controllers and connections for serial, parallel and USB ports, floppy and hard disks and PCI slots for plugging in cards such as a video card, a modem, and a sound card.

11. Processing Devices(continued)
Processor (Major Part) The processor or CPU (Central Processing Unit) controls the computer. The processor is known as the brains. This does the computer business. CPUs have names, too, such as the Pentium II, III, IV, AMD and Xeon. It executes instructions and transports data around the computer system.

12. Processing Devices(continued)
The CPU temporary stores the instructions and data it is using on chips called Random Access Memory, or RAM. Once the computer is turned off, RAM no longer stores any data. A second kind of memory is called Read Only Memory or ROM. These chips contain the instruction that start the computer when you turn it on. The instructions in ROM typically do not change once this memory is placed on the Motherboard.

13. Output Devices
A computer needs output devices to display the results of its processing. Different types of data are sent to different devices. Text and images are displayed on a computer screen. They can also be printed by a printer. Sound data is sent to speakers inside, or connected to, the computer. You can also connect headphones to a computer to listen to sounds.

14. Storage Devices
Because memory is temporary, a computer needs a secondary location for storing data permanently. Devices such as hard disk drives, flash drives, CDs/DVDs, and online storage are all popular types of secondary storage.

15. Making Computers Work
How does a computer know what to do with data in digital form? Software gives it the instructions it needs. Experts called Programmers write the instructions that become software. Programmers write these instructions, called source code, using a Programming Language, example Postscript, XML, HTML, XHTML and JAVA.

16. System Compatibility
The two most Popular Operating Systems are Microsoft Windows and the Macintosh OS. For many years, the two systems were not compatible. That is, programs written for one OS did not run on the other. Today, some programs are written for both systems. Most files can be written, saved, and read in formats usable in both systems. Also, Utility Programs can translate files that previously may have been unreadable.

17. Compliers and Interpreters
Special programs called Compliers translate the source code into binary form, using only 0s and 1s. The result, called Object Code, can be read and acted on by a computer. Sometimes, programs called Interpreters are used to Translate the Source Code directly into actions, bypassing the need for a complier.

18. Group and Individual Computing
Computer range in size from huge machines as big as a room to devices so small they can fit in your pocket. Each type of computer is suited to handling a particular set of jobs in particular settings. Computer for Organizations – Companies and other organizations use the full range of Computers. Large Organizations can afford the largest and most expensive machines, and such companies are more likely to need all the Processing Power that these huge machines have.

19. Computers for Organizations
Supercomputers – The largest and most powerful computers can process huge amounts of data very quickly. They are also the most expensive computers. Mainframes – The mainframe is another type of computer used by government agencies and large corporations. Mainframes are designed so that many people can use the same secure data at once. Examples: U.S Armed Forces, Universities, Banks and Insurance companies.

20. Computers for Organizations
Servers – Many organizations connect their computers together in a network. All the computers that are part of the network are connected to a computer called a server. The server holds data and programs that people on the network can use on their personal computers. An example of a server is what we have at Patterson M.S. The software applications on the individual computers comes from the server in Mr. Waters office.

21. Computers for Individuals
Most individuals do not need as much computing power as organization do. They typically choose from among four types of computers: Workstations – The most powerful and expensive personal computer are workstations. Architects, engineers, designers, and others who work with complex data use these machines for their power and speed.

22. Computers for Individuals
Desktop Computers – Most individuals use personal computers, or desktop computers, to do everyday jobs more quickly and easily. They are also used to connect to computer networks such as the Internet. Portable Computers – Some computers are powerful enough to do the work of desktop computers but can be easily moved. Laptop and Notebook computers fit in a briefcase or backpack. Smaller still are Netbook computer, also called Subnotebooks or Mini Laptops.

23. Computers for Individuals
A Mini Netbook is only 10” across, but does not have a CD-ROM drive. Tablet Computers, such as Apple’s iPad and Android Tablets, are also portable. Handheld Computers – Computers small enough to fit in your pocket are called handheld computers, personal data assistants (PDA), or, with phone service, a smart phone. Handhelds provide basic organizational features such as address / phone books, to do lists, and calendar functions, but can also be used with a wide variety of “apps” to run programs, play games, and interface with a PC.

24. Basic Steps to Start a Computer
Input – enter external instructions via input
devices or instructions entered from within the
computer, such as from the CPU or Math Co-
Processor (example: Power Button and Keyboard)
Processing – once the instructions are entered they
are then processed throughout the computer’s CPU
(Pentium Processor) via operating system software
or application software.
Output – after the information is processed it then
can be retrieved for further use, ex: sent to monitor
for viewing or sent to the printer for hard copy.