1. Computers and Computer Systems
Lesson 1
Computers and Computer Systems

2. Objectives Understand the importance of computers.
Define computers and computer systems.
Classify computers.
Use computer systems.
Identify system components.
Identify types of storage devices.
Care for storage media.
Explore computers in your future.
Objectives

3. Arithmetic/logic unit (ALU): Performs arithmetic computations and logical operations.
Central processing unit (CPU): Also called the microprocessor or central processor, is the brains of the computer.
Circuit board: A thin plate or board that contains electronic components.
Computer: An electronic device that receives data (input), processes data, stores data, and produces a result (output).
Control unit: The boss, so to speak, and coordinates all of the processor’s activities.
Data: Text, numbers, sound, images, or video.
Hard disk: Used to store data inside the computer, although external hard disks are also available.
Vocabulary

4. Hardware: The actual machine—wires, transistors, and circuits.
Information: Output.
Memory: Where data is stored on the motherboard.
Mobile device: Computers that can fit into the palm of your hand.
Motherboard: A circuit board that contains many integral components.
Notebook computer: Today’s most widely used personal computer, designed for one person to use at a time.
Vocabulary

5. Random access memory (RAM): The main memory or primary memory on the motherboard.
Read-only memory (ROM): The permanent storage of data, usually burned onto chips.
Server: A computer generally used by small to medium-size companies and can support a few users or hundreds of users.
Software: Consists of instructions or programs for controlling the computer.
Supercomputer: The fastest type of computer used to process enormous amounts of data.
Tablet PC: A personal computer similar in size and thickness to a notepad.
USB flash drive: A small removable data storage device.
Vocabulary

6. Understanding the Importance of Computers
Invention of Computer
The computer is one of the most important inventions of the past century.
You find computers and computer technology everywhere throughout society—from businesses and financial organizations, to home electronics and appliances, and to personal applications such as clothing embedded with iPod controls.
Understanding the Importance of Computers

7. Understanding the Importance of Computers
A Brief History of the Computer
The first computers were developed in the late 1940s and early 1950s for use by the military and government.
UNIVAC and ENIAC
Less processing power than an iPhone
Occupied a small building or city block
Cost millions of dollars
Computers in mid 50s—70s were smaller and more powerful but still limited
Understanding the Importance of Computers

8. Understanding the Importance of Computers
A Brief History of the Computer (cont.)
In 1971, Dr. Ted Hoff developed the microprocessor.
The first Apple computer was built in 1976 by Steve Jobs and Steve Wozniak. The IBM PC was introduced in 1981.
Understanding the Importance of Computers

9. Understanding the Importance of Computers
FIGURES on PAGES Mod 1-4 & 1-5
Students doing online research
Early computers
The Apple II and IBM PC
Understanding the Importance of Computers

10. Understanding the Importance of Computers
Above and Beyond: The first IBM PC ran on a 4.77 MHz Intel 8088 microprocessor. The PC came equipped with 16 kilobytes (KB) of memory, expandable to 256 KB. The PC came with one or two 160KB floppy disk drives and an optional color monitor.
Understanding the Importance of Computers

11. Defining Computers and Computer Systems
A computer is an electronic device that receives data (input), processes data, stores data, and produces a result (output).
A computer system includes hardware, software, data, and people.
The actual machine — wires, transistors, and circuits — is called hardware.
Defining Computers and Computer Systems

12. Defining Computers and Computer Systems
Software consists of instructions or programs for controlling the computer.
Data is text, numbers, sound, images, or video.
The computer receives data through an input device, processes the data, produces the output (or information), and stores the data and information on a storage device.
Defining Computers and Computer Systems

13. Defining Computers and Computer Systems
FIGURES on PAGES Mod 1-6 & 1-7
Using a mobile computer to process data into information
Information processing cycle
Consists of four steps: I-P-O-S
Defining Computers and Computer Systems

14. Defining Computers and Computer Systems
IPOS example:
Inputs Data: Store clerk enters customer’s name and scans the barcode of an item with an input devices such as keyboard and digital scanner.
Processes Data: Computer uses stored instructions to process data into information.
Outputs Information: Output device, such as monitor or printer, displays the information.
Stores Data & Information: Data and information stored in temporary memory and then to permanent storage.
Defining Computers and Computer Systems

15. Defining Computers and Computer Systems
Computers performs only two operations:
Arithmetic computations
add, subtract, multiply, and divide as well as comparisons such as greater than, less than, or equal to.
Logical operations
using logical operators, such a AND, OR, and NOT
Above and Beyond: Deep Blue was a chess-playing computer developed by IBM. On May 11, 1997, the machine won a six-game match by two wins to one with three draws against world champion Garry Kasparov.
Defining Computers and Computer Systems

16. Classifying Computers
Special-purpose computers are used mostly to control something else.
Dishwashers
Bathroom Scales
Airport Radar Systems
General-purpose computers are divided into categories, based on their physical size, function, cost, and performance.
Classifying Computers

17. Classifying Computers
Types General Purpose Computers
Desktop and Notebook/Laptop are today’s most widely used personal computers, which are designed for one person to use at a time.
PCs and Macs
Tablet PCs are similar in size to a notepad. They function as a PC as well as a portable note-taking device.
Mobile devices fit in the palm of your hand.
Calculators, Smartphones, electronic organizers, etc.
All-in-One
Smaller version of laptop
Classifying Computers

18. Classifying Computers
Types of computers (cont.)
Servers are used by small/medium companies to support few to hundreds of users. Usually referred to as network/application servers.
Web = delivers web pages
Database = stores/manages database info
File = stores remote programs and files that can be shared by users
Mainframe computers are a large, expensive computer capable of supporting hundreds/thousands of users.
Supercomputers are the fastest types of computers. These are used by the Government and large corporations.
Cost = millions of dollars
Classifying Computers

19. Classifying Computers
FIGURE on PAGE 1-10
Electronic book reader
Nook, Kindle, etc.
Above and Beyond: Supercomputers are often used to conduct and test medical experiments
Classifying Computers

20. Using Computer Systems
Computers are used for all kinds of tasks.
Computers take raw data and change it into information. An example of the procedure:
You enter programs and data with some type of input device.
The computer uses instructions to process the data and to turn it into information.
You send the information to some type of output device.
You store it for later retrieval.
Using Computer Systems

21. Using Computer Systems
Technology Careers - Computers on the Job: In the past few decades, computers have had dramatic effects on how we live, learn, and work. For example, the kinds of jobs available have changed because of computers. Fifty years ago, only a handful of people were computer programmers, and none were Web designers or software entrepreneurs. Today, nearly all jobs require some computer skills.
Using Computer Systems

22. Using Computer Systems
Time-consuming, labor-intensive communication tasks that used to require face-to-face meetings, telephone calls, overnight deliveries, or paging through printed materials are now performed quickly and efficiently using Internet browsers and . Students can participate in distance-learning classes to take courses not available where they live. Even the electric-meter reader and delivery person now carry hand-held computers that track a consumer’s electricity use or the location of a package. Cashiers use computers for retail sales, and managers use them to update the store’s inventory, handle customer calls, and advertise products. All of these advances, now taken for granted by many of us, are recent innovations.
Using Computer Systems

23. Using Computer Systems
FIGURE on PAGE Mod 1-11
Computer system components contained within the system’s case
Using Computer Systems

24. Identifying System Components
The motherboard (aka: system board) is a circuit board that contains integral components — central processing unit, memory, connectors, and expansion ports and slots.
Motherboard
Identifying System Components

25. Identifying System Components
The Central Processing Unit
The central processing unit (CPU) is the brains of the computer. It is housed on a tiny silicon chip.
Contains millions of switches and pathways
Programs (aka: Software) are a special set of instructions to control the activities of the computer.
Dual-core contains two separate processors on a single chip
Multicore is expansion for more than two (2) separate processors
Speeds are generally measured in Gigahertz
Current speeds are 2GHz – 4GHz
Identifying System Components

26. Identifying System Components
The Central Processing Unit (cont.)
The CPU has two primary sections: the arithmetic/logic unit and the control unit.
The Arithmetic/Logic Unit (ALU)
Performs arithmetic computations
Addition, Subtraction, Multiplication, and Division
Performs logical operations
Comparisons (AND, OR, NOT)
Two numbers equal or if one number is greater than or less than another number
Can execute complex tasks by combining arithmetic and logical operations:
Video Games use arithmetic operations and comparisons to determine what appears on screen
Identifying System Components

27. Identifying System Components
The Control Unit
The control unit coordinates all of the processor’s activities.
You communicate with the computer through programming languages.
The computer uses machine language, or binary code, which contains only 1s and 0s.
Communicate with computer via programming languages:
Java, COBOL, C++
Identifying System Components

28. Identifying System Components
Recognizing How a Computer Represents Data
Control Unit reads and interprets program instruction into machine language. When electricity travel through processor pathways, it turns switches on and off. This represents the 1s and 0s.
Electricity Present = 1
Electricity Absence = 0
Identifying System Components

29. Identifying System Components
Recognizing How a Computer Represents Data (cont.)
The control unit sends out necessary messages to execute the instructions. A single zero (0) or a single one (1) is a bit, which is the smallest unit of information storage. A byte is a single character, such as a letter or number.
Identifying System Components

30. Identifying System Components
Memory
Memory is where data is stored on the motherboard.
Memory can be short term or long term.
When you want to store a file or information permanently, you use secondary storage devices such as the computer’s hard drive or a USB drive. You might think of this as long term memory.
Identifying System Components

31. Identifying System Components
Random Access Memory
The memory on the motherboard is short term, called random access memory (RAM).
Data, information, and program start-up instructions are stored temporarily on a RAM chip and disappear when the computer is turned off or there is a power loss.
The instruction cycle is the amount of time it takes to retrieve instructions to perform a specified task and complete the command.
The execution cycle refers to the amount of time it takes the CPU to execute the instruction and store the results in RAM.
Identifying System Components

32. Identifying System Components
Random Access Memory (cont.)
Together, the instruction cycle and one or more execution cycles create a machine cycle.
For every instruction, a processor repeats a set of four basic operations, which compose a machine cycle
Fetching – Obtaining a program instruction or data from RAM
Decoding – Process of translating the instruction into signals
Executing – Process of carrying out commands
Storing – Writing result to memory
Identifying System Components

33. Identifying System Components
Processing Cycle
Machine Cycle
Identifying System Components

34. Identifying System Components
Read-Only Memory
Another type of memory found on the motherboard is read-only memory (ROM).
ROM chips store specific instructions that are needed for computer operations. These instructions remain on the chip even when the power is turned off, because ROM chips are nonvolatile.
The more common of these is the BIOS ROM, containing instructions to start the system when you turn on the computer.
Identifying System Components

35. Identifying System Components
Above and Beyond: Cache memory is another type of memory. This high-speed RAM is used to increase the speed of the processing cycle.
Above and Beyond: If you read computer ads, you are likely to see the abbreviations MHz (megahertz) and GHz (gigahertz). These speed specifications indicate the speed of the microprocessor clock—a timing device that specifies the speed for executing instructions.
Above and Beyond: In the time it takes to blink your eyes, certain computers can perform certain operations 10 billion times.
Identifying System Components

36. Identifying System Components
RAM Microprocessor
Identifying System Components

37. Identifying Types of Storage Devices
To keep a permanent copy of data, you must store it on a storage device.
Magnetic Storage Devices
Data is stored in numbered tracks in a special log on the disk called a file allocation table (FAT).
Hard Disks
Magnetic Tape
Zip Disks
3½” Disks
Hard Disks (aka: Hard Drives)
Store data inside computer, or outside via external HD
Advantages: speed and capacity.
Measured in Gigabytes or Terabytes
Identifying Types of Storage Devices

38. Identifying Types of Storage Devices
Removable Disks
Removable magnetic media are rarely used and include 3½” disks and Zip disks.
Optical Storage Devices
Use laser technology to read and write data on plastic platters that contain a metal layer, like CDs, DVDs, etc.
CD-DA = audio CD
CD-R = Write once CD
CD-ROM = Store up to 1 GB but common size is 650 MB or 74 minutes
CD-RW = Rewritable CD; erase data and write multiple times
DVD-ROM = Movies and Games; Capacities from 4.7–17 GB
DVD-R = Write once DVD
DVD-RW = Rewritable DVD; erase data and write multiple times
Blu-Ray = 5 times storage capacity of DVD; Capacities from GB
Identifying Types of Storage Devices

39. Identifying Types of Storage Devices
Solid-State Storage Media
Nonvolatile, removable medium that uses integrated circuits
USB flash drive
AKA: Key Drive, Thumb Drive, Jump Drive, USB Flash Memory, and USB Stick
SD Cards
Compact Flash Card
Network Drives
Hard drive or tape drive located on computer other than user’s computer
Connected to a network server and is available to and shared by multiple users.
Remote storage is used to extend disk space on a server and to eliminate the addition of more hard disks or other storage devices.
Identifying Types of Storage Devices

40. Identifying Types of Storage Devices
Above and Beyond: Blu-ray optical discs use a blue-violet laser to read and write data, unlike earlier optical discs such as DVDs, which use a red laser. Although they use different lasers, Blu-ray products can be backwards compatible with CDs and DVDs.
Identifying Types of Storage Devices

41. Identifying Types of Storage Devices
Internals of Hard Drive
Platter
Spindle
Head
Actuator Arm
Actuator
Identifying Types of Storage Devices

42. Identifying Types of Storage Devices

43. Identifying Types of Storage Devices
Miniature Mobile Storage Media
Examples of USB Flash Drives
Identifying Types of Storage Devices

44. Caring for Storage Media
Keep away from magnetic fields.
Avoid extreme temperatures.
Remove media from drives and store them properly when not in use.
When handling DVDs and other optical discs, hold them at the edges.
Never try to remove the media from a drive when the drive indicator light is on.
Keep discs in a sturdy case when transporting.
Caring for Storage Media

45. Exploring Computers in Your Future
A major focus of new types of computers is connectivity, or the ability to connect with other computers.
Wireless and mobile devices are now as common as wired desktop machines.
Computer literacy, which is the knowledge and understanding of computers and their uses, will become even more important.
Exploring Computers in Your Future

46. 1) Who built the first Apple computer
1) Who built the first Apple computer? Answer: Steve Jobs and Steve Wozniak 2) True or False? Many people consider the computer to be the single most important invention of the 20th century. Answer: True. 3) True or False? Machines like the UNIVAC and ENIAC were designed initially for use by schools. Answer: False. Machines like the UNIVAC and ENIAC were designed initially for use by the military and government.
QUICK QUIZZES

47. 4) A computer __________ includes hardware, software, data, and people
4) A computer __________ includes hardware, software, data, and people. Answer: system 5) __________ is text, numbers, sound, images, or video. Answer: Data 6) Which type of computer is designed for one person to use at a time? A. personal computer B. server Answer: A 7) Tiny chips embedded in dishwashers, bathroom scales, or airport radar systems are classified as __________ computers. A. general-purpose B. special-purpose Answer: B
QUICK QUIZZES

48. 8) True or False? Just about all computers, regardless of size, take raw data and change it into information. Answer: True. 9) The __________ that the computer uses to process data are contained within the system case. Answer: components 10) Computers follow the __________ procedure—input, processing, output, and storage. Answer: IPOS
QUICK QUIZZES

49. 11) The central processing unit (CPU), also called the microprocessor or central processor, is the __________ of the computer. Answer: brains 12) True or False? The arithmetic/logic unit (ALU) is the boss of the CPU. Answer: False. The arithmetic/logic unit (ALU) performs arithmetic computations and logical operations. 13) True or False? The computer does not understand human language. Answer: True. 14) A __________ is the smallest unit of information storage. Answer: bit
QUICK QUIZZES

50. 15) True or False? Random access memory, or RAM, is considered short term memory. Answer: True. 16) __________is the process of obtaining a program instruction or data item from RAM. Answer: Fetching 17) __________ is a nonvolatile, removable medium that uses integrated circuits. A. Optical storage B. Magnetic storage C. Solid-state storage D. None of the above Answer: D
QUICK QUIZZES

51. 18) True or False? Most hard disks are used to store data inside the computer. Answer: True. 19) True or False? A network drive is located on a computer other than the user’s local system. Answer: True 20) True or False? You should hold DVDs at the edges.
QUICK QUIZZES

52. 21) True or False? It is okay to remove media from a drive when the drive indicator light is on. Answer: False. 22) True or False? Wireless and mobile devices are not as common as wired desktop machines. Answer: False. 23) True or False? Computer literacy is the knowledge and understanding of computers and their uses. Answer: True.
QUICK QUIZZES