Chapter 03 – Computer Hardware
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3 Computer Hardware
CHAPTER OVERVIEW
Chapter 3: Computer Hardware reviews history, trends, and developments in microcomputer, midrange, and
LEARNING OBJECTIVES
After reading and studying this chapter, you should be able to:
1. Understand the history and evolution of computer hardware.
2. Identify the major types and uses of microcomputer, midrange, and mainframe computer systems.
SUMMARY
• Computer Systems. Major types of computer systems are summarized in Figure 3.3 . Microcomputers are used as
personal computers, network computers, personal digital assistants, technical workstations, and information
appliances. Midrange systems are increasingly used as powerful network servers and for many multiuser business
data processing and scientific applications. Mainframe computers are larger and more powerful than most midsize
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KEY TERMS AND CONCEPTS
1. Binary representation (108):
2. Central processing unit (93):
The component of a computer system that includes the circuits controlling the interpretation and execution of
instructions. The CPU includes the arithmetic-logic unit and the control unit.
3. Computer system (92):
4. Computer terminal (85):
A terminal is any device that enables both input and output between a user and a computer via
telecommunications link.
5. Cycles per second (94):
Denoted as Hz, cycles per second is a measure of the speed of the computer’s timing circuits or internal clock.
6. Direct access (109):
A method of storage where each storage cluster has a unique address and can be individually accessed in
7. Graphical user interface (97):
A design approach that enables users to interact with a computer by manipulating images or “icons” that
represent objects or actions.
8. Information appliance (86):
9. Magnetic disks (112):
Data storage technology that uses magnetised spots on metal or plastic disks.
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b. Hard disk (113):
A secondary storage medium consisting of metal disks covered with a magnetic recording surface. It holds
ranges up to 1.5 TB and continues to increase.
c. RAID (Redundant array of independent disks ) (113):
A RAID array comprises two or more interconnected microcomputer hard disk drives and their controllers.
10. Magnetic stripe (105):
A strip of magnetic tape embedded in a plastic card and widely used for credit/debit cards and identification
cards. These stripes hold up to 200 bytes of information.
11. Magnetic tape (113):
12. Mainframe system (89):
This category comprises large, fast, and powerful computer systems. Processing speeds range up to billions of
13. Microcomputer (83):
14. Midrange system (87):
Larger, more powerful, and more expensive than most microcomputers but are smaller, less powerful, and less
15. Minicomputer (88):
This category comprises mid-range computer that might be used as a high-end workstation for computationally
16. MIPS (94):
An acronym standing for Millions of Instructions per Second. This is a way of measuring relative CPU speed
(see also cycles per second – measured in MHz)
17. Moore’s law (94):
Moore predicted that the number of transistors per integrated circuit will double every 18 to 24 months.
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18. Network computer (86):
19. Network server (83):
20. Network terminal (85):
A terminal that depends on network servers for its software and processing power.
21. Off–line (97):
22. Online (97):
Pertains to equipment or devices under control of the central processing unit or that are connected to a network.
23. Optical disks (114):
24. Optical scanning (103):
Using a device (scanner) that reads characters or images and generates their digitally coded representations.
25. Peripherals (97):
26. Pointing devices (97):
Devices which enables end users to move a cursor on the display screen.
28. Processing speed (94):
see also “cycles per second” and “MIPS”.
a. Millisecond (94):
29. RFID (115):
Radio Frequency Identification Device. A class of small active or passive transmitters that can be embedded in
or affixed to objects to facilitate identification and tracking.
Chapter 03 – Computer Hardware
30. Secondary storage (93):
External or auxiliary storage device that supplements the primary storage of a computer. Examples include
31. Semiconductor memory (110):
Microelectronic storage circuitry etched on tiny chips of silicon or other semiconducting material.
a. Semiconductor memory – RAM (110):
32. Sequential access (109):
33. Speech recognition (101):
Direct conversion of spoken data into digital characters. As this technology develops, it promises to be the most
natural way to communicate with computers. Current accuracy rates range up to 95%.
34. Storage capacity (109):
Units used for storage capacity and data: bits (b), bytes (B), kilobytes (KB), megabytes (MB), gigabytes (GB),
terabytes (TB), Petabyte (PB).
a. Bit – “b” (108):
A contraction of “binary digit”. It can have the value of either 0 or 1.
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35. Supercomputer (90):
36. Volatility (110):
Memory (RAM) that loses its contents when electrical power is interrupted.
37. Workstation computer (83):
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ANSWERS TO REVIEW QUIZ
Q.
A.
Key Term
Q.
A.
Key Term
1
3
Computer system
28
17
Moore’s law
2
2
Central processing unit
29
33
Speech recognition
10
1
Binary representation
37
34a
Bit
11
7
Graphical user interface
38
34f
Terabyte
12
13
Microcomputer
39
31b
ROM
13
14
Midrange system
40
31a
RAM
14
9a
Floppy disk
41
36
Volatility
15
9b
Hard disk
42
6
Direct access
18
Network computer
43
32
Sequential access
17
9c
RAID
44
31
Semiconductor memory
18
20
Network terminal
45
9
Magnetic disks
19
19
Network server
46
11
Magnetic tape
20
35
Supercomputer
47
23
Optical disks
21
10
Magnetic stripe
48
28b
Microsecond
Nanosecond
49
28d
Picosecond
23
Gigabyte
50
34b
Byte
25
15
Minicomputer
52
34d
Megabytes
26
12
Mainframe system
53
34g
Petabyte
27
16
MIPS
3
5
Cycles per second
30
24
Optical scanning
4
8
Information appliance
31
28
Processing speed
5
27
Primary storage unit
32
28a
Millisecond
6
30
Secondary storage
33
34c
Kilobyte
7
25
Peripherals
34
4
Computer terminal
8
22
Online
35
34
Storage capacity
9
21
36
37
Workstation computer
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ANSWERS TO DISCUSSION QUESTIONS
1. What trends are occurring in the development and use of the major types of computer systems?
Computers are becoming physically smaller, faster, with more memory, cheaper, more reliable, and user
friendly. They are increasingly being connected via telecommunications links throughout organizations.
2. Will the convergence of PDAs, subnotebook PCs, and cell phones produce an information appliance that
will make all of those categories obsolete? Why or why not?
There is no doubt that the convergence of PDAs, sub-notebook PCs, and cell phones will produce an
3. Refer to the Real World Case IT asset management in the chapter. What advice would you provide to a
growing company to avoid facing the issues discussed in the case?
Full blown asset management systems are expensive to buy and implement – especially for a small to mid-sized
organization. IT departments in growing companies should establish procedures for purchasing and tracking
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4. Do you think that information appliances like PDAs will replace personal computers (PCs) in business
applications? Explain.
If PDAs continue to grow in power, storage capacity, and in ability to connect with peripheral devices (via
Bluetooth, for example), then there is no reason they can’t replace personal computers.
5. Are networks of PCs and servers making mainframe computers obsolete? Explain.
Mainframe sales continue to trend upward. Reasons given include increased global demand for computing
6. Refer to the Real World Case on speech recognition in health care in the chapter. Although these and
other technologies are becoming more prevalent in health care, doctors have traditionally been reluctant to
adopt them. Why do you think this is the case? How would these technologies change the way doctors
perform their job?
Reasons for doctors’ resistance
• too busy to learn
7. What are several trends that are occurring in computer peripheral devices? How do these trends affect
business uses of computers?
Trends
• “plug and play” capability
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8. What are several important computer hardware developments that you expect to happen in the next 10
years? How will these affect the business use of computers?
Developments:
• Hardware devices will increase in speed and capacity.
• Hardware devices will decrease in size and cost.
9. What processor, memory, magnetic disk storage, and video display capabilities would you require for a
personal computer that you would use for business purposes? Explain your choices.
Note: all business computing requirements lists should include data backup and recovery hardware and
software when network backups are not available daily. All home computing requirement lists should also
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Explanation:
1. Multi-core processes allow the operating system to free up more CPU cycles for computationally
intensive applications. Examples include analytical software, video rendering applications, and data
processing software. This means that while the computer churns away at a large, critical problem, the
user can still access other applications without lag.
2. The monitor is the desktop today. A large monitor enables multi-tasking without placing undo
4. 32-bit processors are limited by their 32-bit word size to a maximum of 4 billion unique address
locations. As a result, they can not take advantage of more than 4 GB of memory (actually, just a little
less). Video processing, image processing, and data processing software, and multi-tasking all require
significant amounts of memory. While modern operating systems can take advantage of “virtual
memory”, this reliance will negatively affect a computers’ performance.
10. What other peripheral devices and capabilities would you want to have for your business PC? Explain
your choices.
Uninterrupted Power Supply (UPS)
All computers should connect to a UPS. This helps prevent damage due to variances in power supply, preserves
data, and decreases user frustration which invariable results from lost work.
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ADA (Americans with Disabilities Act) compliant I/O devices
Employees, customers, and business partners may require additional assistance, and the appropriate tools should
be readily available.
Noise cancellation microphones
Noise cancelling microphones allow clearer speech recording. This greatly improves the quality of audio
communications (phone, voice mail, and digital voice recording). It also significantly improves the
interpretation accuracy of speech recognition systems.
Large, multiple monitors
The computer monitor has become the new workplace desktop. With larger monitors and multiple monitors,