Foundations of Information Science I 1 Introduction This class covers computing basics, including: Computing Fundamentals focuses on hardware and software. Microsoft Office 2010 applications focuses on how to use Microsoft Word, Excel, and PowerPoint Communication network fundamentals focuses on how to use computers are used at work and home, and discuss the risks of using hardware and software and using the Internet safely, ethically, and legally.
2 Lesson 1 2.1 Computers and Computer Systems 2.1.1 Objectives Upon completion of this lesson, you should be able to: (1) Use computer systems. (2) Identify system components. (3) Describe the role of the central processing unit. (4) Define computer memory. (5) Describe how data is represented. (6) Identify types of storage devices. (7) Care for storage media. 2.1.2 Using Computer Systems Computers are used for all kinds of tasks to predict weather, to fly airplanes, to control traffic lights, to play games, to access the Internet, to send e mail, etc. Still more, we use computers without being aware of their presence they are microcomputers that are embedded in your cell phones, air conditioners, cars, rice cookers, and so on. What do the computers do? We need a fundamental understanding. Just about all computers, regardless of size, take raw data and change it into information. The procedure involves input, processing, output, and storage (IPOS). For example: You input programs and data with some type of input device. The computer uses instructions to process the data and turn it into information. You send the information to some type of output device. You store it for later retrieval. Figure 1 Functions of a computer system
2.1.3 System Components Central to the PC system is the motherboard or system board that mounts into the case. The motherboard is a circuit board that contains many integral components. A circuit board is a thin board that contains mounted thereon electronic components. Some of the most important of these are: Central Processing Unit Memory Basic controllers Expansion ports and expansion slots Figure 2 An example of the components mounted on a motherboard. http://www.computer hardware explained.com/what is a motherboard.html 2.1.3.1 The Central Processing Unit (CPU) Also called the microprocessor or central processor, is the brains of the computer. The processor is housed on a tiny silicon chip as shown in Figure 3 below. The chip contains millions of switches and pathways that help your computer make important decisions. The switches control the flow of the electricity as it travels across the miles of pathways. The processor knows which switches to turn on and which to turn off because it receives its instructions from computer programs. Programs are a set of special instructions, written by programmers, which control the activities of the computer. Programs are also known as software. Figure 3 Microprocessors (left: Intel Core 2 Quad, right: AMD Phenon II) Dual core and multicore processors are now provided by chip manufacturers. A dual core processor is a single chip that contains two separate processors, and a multicore processor is an expansion that provides for more than two separate processors. These processors do not necessarily double the processing speed of a single core processor, but do provide higher performance when running multiple programs simultaneously. The CPU has two primary sections; the arithmetic/logic unit and the control unit. The arithmetic/logic unit (ALU) performs arithmetic computations and logical operations. The control unit coordinates all of the processor s activities.
2.1.3.2 How a Computer Represents Data The control unit reads and interprets the program instruction and changes the instruction into machine language. As electricity travels through processor pathways, the turning on and off of switches represents the 1s and 0s. When electricity is present, it represents a 1. The absence of electricity represents 0. After changing the instructions into machine language (binary), the control unit then sends out the necessary messages to execute the instructions. A single zero or a single one is called a bit. Eight bits are equal to one byte. A byte is a single character. Table 1 Units of data TERM ABBREVIATION BYTES Kilobyte KB 1,024 (approx. 1,000) Megabyte MB 1,048,576 (approx. 1 million) Gigabyte GB 1,073,741,824 (approx. 1 billion) Terabyte TB 1,099,511,627,776 (approx. 1 trillion) Exercise 1 1 (1) From [All Programs] in the [Start] button, click [Calculator]. (2) Click [View] on the menu bar and then click [Programmer]. (3) Click the [Dec] (decimal) option button. Enter 20 by clicking the calculator numerical buttons. Click the [Bin] (binary) option button. The number 10100 is displayed. (4) Convert decimal number 4545 to binary: Convert decimal number1112 to binary: (5) Convert binary number 1111011 to decimal: Convert binary number 101101 to decimal: Memory A memory restores data. Memories can be classified in two from the viewpoint of the term for storage. Random Access Memory (RAM) This type of memory, which is also referred to as main memory or primary memory, is mounted on the motherboard to store the data for a short term. The computer can read from and write to this type of memory. Data and program instructions are stored temporarily within the CPU on a RAM chip or a set of RAM chips. When the computer is turned off or otherwise loses power, whatever is stored in the RAM memory chips disappears. Therefore, it is considered volatile. Let us think about how the RAM functions in working with a word processing program:
1. First, you start your word processing program. The computer then loads your word processing program instructions into RAM. 2. You input data or words (that are converted into a machine readable data). The data is also stored in RAM. 3. Next, you give your word processing program a command to process the data by arranging it in a special format. This command and your processed data are also now stored in RAM. 4. You then click the [Print] button. Instructions to print are transmitted to RAM and your document is sent to a printer. 5. Then, you click the [Save] button. Instructions to provide you with an opportunity to name and save your file are loaded into RAM. Once you save your file, you exit your word processing program and turn off the computer. 6. All instructions, data, and information that you used to create your report are erased from RAM. This process is known as the instruction cycle or I cycle, and the execution cycle or e cycle. For every instruction, a processor repeats a set of four basic operations, which compose a machine cycle: (1) fetching, (2) decoding, (3) executing, and, if necessary, (4) storing. 2. The control unit decodes the instruction and sents it to the ALU 1. The control unit fetches the instruction from memory(ram) RAM Control Unit 3. The ALU executes the instruction ALU 4. The result of the instruction execution is stored in RAM Figure 4 Processing cycle Read Only Memory (ROM) Another type of memory is read only memory (ROM). ROM chips are also found in all types of computer systems, because they store specific instructions that are needed for computer operations. This type of memory is non volatile, and restores the instructions when the power is turned off. The more common of these is the BIOS ROM.
2.1.4 Storage Devices If we want to keep a permanent copy of the data, we must store it on some type of storage medium, which may be magnetic, optical, or solid state device. Magnetic Storage Devices Magnetic storage devices use oxide coated plastic storage media called Mylar. The more common types of magnetic storage media are hard drives, magnetic tape, 3.5 inch disks, etc. Optical Storage Devices Optical storage devices use laser technology to read and write data on platters. The term disc is used for optical media. CD (Compact Disc)s and DVD(Digital Versatile Disc)s are at type of optical storage media. These storage devices can be further classified depending on the mode of data storage: CD R, DVD R : The compact disc or digital versatile disc recordable format CD ROM, DVD ROM: Read only memory format CD RW, DVD RW: Rewritable format Blu ray: The format provides more than five times the storage capacity of traditional DVDs. Solid state Storage Media Also referred to as removal media, is a non volatile, removable medium that uses integrated circuits. The main advantage of this type of storage medium is that everything is processed electronically. Examples of the media include MD cards such as Compact Flash, Memory Stick, and Microdrive. Another popular solid state storage medium is the USB flash drive. 2.1.5 Vocabulary Review Define the following terms: ALU CPU motherboard memory RAM ROM USB flash drive 2.1.6 Review Questions Multiple choice Select the best response for the following statements:
1. A consists of hardware, software, data, and users. a. client b. node c. mobile device d. computer system 2. A generally can fit into the palm of your hand. a. mainframe computer b. supercomputer c. mobile device d. notebook computer 3. The is a circuit board that contains many integral components. a. supercomputer b. motherboard c. ALU d. BIOS ROM 4. devices use laser technology to read and write data on platters a. Output b. 3.5 inch c. Solid state d. Optical storage 5. Random access memory is. a. permanent b. non volatile c. volatile d. the same as ROM Fill in the Blank 1. You can think RAM as term memory. 2. The instruction cycle and the execution cycle create a(n) cycle. 3. The faster the machine cycle, the your computer processes data. 4. The two primary sections of the CPU are the and the control unit. 5. Read only memory (ROM) is and is used to store permanent instructions needed for computer operations. Projects Project 1 1 In the desktop, select [Computer] icon, and right click to show the context menu. Select [properties] to find your hardware and software information of your computer system. Figure 5 Know about your computer system
Project 1 2 Access the Dell Computer Web site (www.dell.com). Select either the Home and Office Laptops or Home and Office Desktops category. Create a comparison table using a word processing software or paper and pencil. Include the following elements in your table: processor speed, amount of RAM, number of expansion slots, number of USB ports, other ports, and price. Based on your comparisons, write a short paragraph explaining which computer you would purchase and why.