Management Information Systems, 13TH ED.
MANAGING THE DIGITAL FIRM
Kenneth C. Laudon ● Jane P. Laudon
continued
Learning Track 1: How Computer Hardware and Software Work
Although managers and business professionals do not need to be computer technology experts,
they should have a basic understanding of the role of hardware and software in the organiza-
Computer Hardware and Information Technology
Infrastructure
Computer hardware provides the underlying physical foundation for the firm’s IT infrastructure.
Other infrastructure components—software, data, and networks—require computer hardware for
their storage or operation.
The Computer System
A contemporary computer system consists of a central processing unit, primary storage, second-
ary storage, input devices, output devices, and communications devices (see Figure 4–1). e
central processing unit manipulates raw data into a more useful form and controls the other parts
Chapter 5: IT Infrastructure and Emerging Technologies
Chapter 5 Learning Track 1 2
continued
FIGURE 4-1 Hardware Components of a Computer System.
A contemporary computer system can be categorized into six major components. The central process-
ing unit manipulates data and controls the other parts of the computer system; primary storage tempo-
rarily stores data and program instructions during processing; secondary storage stores data and instruc–
FIGURE 4-2 Bits and Bytes.
Chapter 5 Learning Track 1 3
continued
The CPU and Primary Storage
e central processing unit (CPU) is the part of the computer system where the manipulation of
symbols, numbers, and letters occurs, and it controls the other parts of the computer system (see
Figure 4–3). Located near the CPU is primary storage (sometimes called primary memory or main
THE ARITHMETIC-LOGIC UNIT AND CONTROL UNIT
Figure 4–3 also shows that the CPU consists of an arithmetic-logic unit and a control unit. e
arithmetic–logic unit (ALU) performs the computer’s principal logical and arithmetic operations.
FIGURE 4-3 The CPU and Primary Storage.
The CPU contains an arithmetic-logic unit and a control unit. Data and instructions are stored in unique
addresses in primary storage that the CPU can access during processing. The data bus, address bus, and
control bus transmit signals between the central processing unit, primary storage, and other devices in
the computer system.
continued
e control unit coordinates and controls the other parts of the computer system. It reads a stored
PRIMARY STORAGE
Primary storage has three functions. It stores all or part of the software program that is being
executed. Primary storage also stores the operating system programs that manage the operation
of the computer. Finally, the primary storage area holds data that the program is using. Internal
TABLE 4-1 Computer Storage Capacity
Byte String of eight bits
Primary storage is composed of semiconductors, which are integrated circuits made by printing
thousands and even millions of tiny transistors on small silicon chips. ere are several different
Chapter 5 Learning Track 1 5
continued
Computer Processing
e processing capability of the CPU plays a large role in determining the amount of work that a
computer system can accomplish.
MICROPROCESSORS AND PROCESSING POWER
Contemporary CPUs use semiconductor chips called microprocessors, which integrate all of the
memory, logic, and control circuits for an entire CPU onto a single chip. e speed and perfor-
mance of a computer’s microprocessors help determine a computer’s processing power and are
A third factor affecting speed is the data bus width. e data bus acts as a highway between the
CPU, primary storage, and other devices, determining how much data can be moved at one time.
e 8088 chip used in the original IBM personal computer, for example, had a 16-bit word length
but only an 8-bit data bus width. is meant that data were processed within the CPU chip itself
Chapter 5 Learning Track 1 6
continued
MULTI-CORE PROCESSORS
Microprocessors were originally designed and manufactured as a single core processing unit
with a single logic unit, a local memory cache, and communications bridge from the processor to
memory, and from memory to various output devices. As more and more transistors were added to
A multi-core processor is a single chip with two, four, eight or more cores which execute the
instructions of computer programs. Generally they operate at 2 Ghz or above. ey achieve much
higher performance by dividing program instructions into separate multiple instructions, and
In 2013 personal computers and smartphones typically use dual or quad core processors. For
instance, the Apple iPhone 5 uses an Apple A6 dual core processor operating at 1.3 Ghz, with a
PARALLEL PROCESSING
Processing can also be sped up by linking several processors to work simultaneously on the same
task. Figure 4–4 compares parallel processing to serial processing used in conventional computers.
In parallel processing, multiple processing units (CPUs) break down a problem into smaller parts
Chapter 5 Learning Track 1 7
continued
FIGURE 4-4 Sequential and Parallel Processing.
Massively parallel computers have huge networks of hundreds or even thousands of processor
chips interwoven in complex and exible ways to attack large computing problems. As opposed to
Storage, Input and Output Technology
e capabilities of computer systems depend not only on the speed and capacity of the CPU but
Secondary Storage Technology
e rise of digital firms has made storage a strategic technology. Although electronic commerce
and electronic business are reducing manual processes, data of all types must be stored electroni-
Chapter 5 Learning Track 1 8
continued
MAGNETIC DISK
e most widely used secondary storage medium today is magnetic disk. ere are two kinds of
magnetic disks: oppy disks (used in PCs) and hard disks (used on large commercial disk drives
and PCs). Large mainframe or midrange computer systems have multiple hard disk drives because
Disk drive performance can be further enhanced by using a disk technology called RAID
(Redundant Array of Inexpensive Disks). RAID devices package more than a hundred disk drives,
a controller chip, and specialized software into a single large unit. Traditional disk drives deliver
data from the disk drive along a single path, but RAID delivers data over multiple paths simultane-
Chapter 5 Learning Track 1 9
SOLID STATE MEMORY
Solid state memory uses transistors to store information, rather than spinning magnetic disks and
optical CDs. As a result, they use much less power than a motor driven magnetic disk, they gener–
ate no heat, and they can access information much faster. e limitation of solid state memory is
storage capacity: today’s hard drives easily store a terrabyte of data, whereas typical ash drives
have only about 16 GB of storage, but can go as high as 64 GB, less than one-tenth the storage of
hard drive.
Solid state memory comes in several form factors. Solid state memories have been used in comput–
OPTICAL DISKS
Optical disks, also called compact disks or laser optical disks, user laser technology to store
massive quantities of data in a highly compact form. ey are available for both PCs and large
computers. e most common optical disk system used with PCs is called CD–ROM (compact
disk read-only memory). A 4.75-inch compact disk for PCs can store up to 660. Optical disks are
Digital video disks (DVDs), also called digital versatile disks, are optical disks the same size as
CD-ROMs but of even higher capacity. ey can hold a minimum of 4.7 gigabytes of data, enough
to store a full-length, high-quality motion picture. DVDs are initially being used to store movies
Chapter 5 Learning Track 1 10
continued
Multimedia combines text, graphics, sound, and
video into a computer–based experience that
permits two-way communication. Many orga–
nizations use this technology for interactive
training.
MAGNETIC TAPE
Magnetic tape is an older storage technology
that still is employed for secondary storage of
NEW STORAGE ALTERNATIVES: STORAGE AREA NETWORKS (SANS)
To meet the escalating demand for data–intensive multimedia, Web, and other services, the amount
of data that companies need to store is increasing from 75 to 150 percent every year. Companies
Chapter 5 Learning Track 1 11
continued
FIGURE 4-5 A Storage Area Network (SAN).
The SAN stores data on many different
types of storage devices, providing data to
Input and Output Devices
Human beings interact with computer systems largely through input and output devices. Input
devices gather data and convert them into electronic form for use by the computer, whereas output
devices display data after they have been processed. Table 4–2 describes the principal input devices,
and Table 4–3 describes the major output devices.
TABLE 4-2 Principal Input Devices
Input Device Description
Keyboard Principal method of data entry for text and numerical data.
Computer mouse Handheld device with point-and-click capabilities that is usually
Chapter 5 Learning Track 1 12
continued
Touch screen Allows user to enter limited amounts of data by touching the surface
of a sensitized video display monitor with a finger or a pointer.
Often found in information kiosks in retail stores, restaurants, and
shopping malls.
Optical character recognition Devices that can translate specially designed marks, characters, and
Magnetic ink character
recognition (MICR)
Used primarily in check processing for the banking industry.
Characters on the bottom of a check identify the bank, checking
account, and check number and are preprinted using a special
magnetic ink. A MICR reader translates these characters into digital
form for the computer.
Pen-based input Handwriting-recognition devices such as pen-based tablets,
notebooks, and notepads convert the motion made by an electronic
TABLE 4-3 Principal Output Devices
Output Device Description
LCD display screens Liquid crystal displays have replaced CRT (cathode ray tube)
displays because of their lighter weight, lower power consumption,
Chapter 5 Learning Track 1 13
continued
Batch and On-Line Input and Processing
e manner in which data are input into the computer affects how the data can be processed.
Information systems collect and process information in one of two ways: through batch or through
Figure 4-6 compares batch and on-line processing. Batch systems often use tape as a storage
medium, whereas on–line processing systems use disk storage, which permits immediate access
to specific items. In batch systems, transactions are accumulated in a transaction file, which
contains all the transactions for a particular time period. Periodically, this file is used to update
a master file, which contains permanent information on entities. (An example is a payroll master
Chapter 5 Learning Track 1 14
FIGURE 4-6 A Comparison of Batch and On-line Processing.
In batch processing, transac–
tions are accumulated and
stored in a group. Because
batches are processed at
regular intervals, such as
Interactive Multimedia
e processing, input, output, and storage technologies we have just described can be used to
create multimedia applications that integrate sound and full-motion video, or animation with
graphics and text into a computer-based application. Multimedia is becoming the foundation of
new consumer products and services, such as electronic books and newspapers, electronic class-
room-presentation technologies, full-motion videoconferencing, imaging, graphics design tools,
Chapter 5 Learning Track 1 15
continued
System Software and PC Operating Systems
System software coordinates the various parts of the computer system and mediates between
application software and computer hardware. e system software that manages and controls the
FUNCTIONS OF THE OPERATING SYSTEM
e operating system is the computer system’s chief manager. e operating system allocates and
assigns system resources, schedules the use of computer resources and computer jobs, and moni-
tors computer system activities. e operating system provides locations in primary memory for
MULTIPROGRAMMING
A series of specialized operating system capabilities enables the computer to handle many differ–
ent tasks and users at the same time. Multiprogramming permits multiple programs to share a
Chapter 5 Learning Track 1 16
continued
FIGURE 4-7 Single-program Execution Versus Multiprogramming.
VIRTUAL STORAGE
Virtual storage handles programs more eciently because the computer divides the programs into
small fixed– or variable–length portions, storing only a small portion of the program in primary
FIGURE 4-8 Virtual Storage.
In virtual storage, programs are broken down
into small sections that are read into memory
only when needed. The rest of the program is
Chapter 5 Learning Track 1 17
TIME SHARING
Time sharing is an operating system capability that allows many users to share computer process-
ing resources simultaneously. It differs from multiprogramming in that the CPU spends a fixed
MULTIPROCESSING
Multiprocessing is an operating system capability that links together two or more CPUs to work
in parallel in a single computer system. e operating system can assign multiple CPUs to execute
LANGUAGE TRANSLATION AND UTILITY SOFTWARE
System software includes special language translator programs that translate high-level language
programs written in programming languages such as COBOL, FORTRAN, or C into machine
language that the computer can execute. e program in the high–level language before translation
PC OPERATING SYSTEMS AND GRAPHICAL USER INTERFACES
Like any other software, PC software is based on specific operating systems and computer hard-
ware. Software written for one PC operating system generally cannot run on another.
When a user interacts with a computer, including a PC, the interaction is controlled by an oper–
Chapter 5 Learning Track 1 18
Application Software and Programming Languages
Application software is primarily concerned with accomplishing the tasks of end users. Many
PROGRAMMING LANGUAGES
e first generation of computer languages consisted of machine language, which required the
programmer to write all program instructions in the 0s and 1s of binary code and to specify
storage locations for every instruction and item of data used. Programming in machine language
was a very slow, labor–intensive process. As computer hardware improved and processing speed
ASSEMBLY LANGUAGE
Assembly language is the next level of programming language up from machine language and is
considered a “second-generation” language. Like machine language, assembly language (Figure 4-9)
FIGURE 4-9 Assembly Language.
This sample assembly language command adds the contents of register 3 to register 5 and stores the
result in register 5. (A register is a temporary storage location in the CPU for small amounts of data or
instructions).
THIRD-GENERATION LANGUAGES: FORTRAN, COBOL, BASIC, PASCAL, AND C
ird-generation languages specify instructions as brief statements that are more like natural
languages than assembly language. All are less ecient in the use of computer resources than
Chapter 5 Learning Track 1 19
continued
◆ FORTRAN FORTRAN (FORmula TRANslator) (Figure 4–10) was developed in 1956 to
FIGURE 4-10 FORTRAN.
This sample FORTRAN program code is part of a program to compute sales figures for a particular item.
◆ COBOL COBOL (COmmon Business Oriented Language) (Figure 4–11) was developed in the
early 1960s by a committee representing both government and industry. Rear Admiral Grace
FIGURE 4-11 COBOL
This sample COBOL program code is part of a routine to compute total sales figures for a particular item.
◆ BASIC and Pascal BASIC and Pascal are used primarily in education to teach programming.
BASIC (Beginners All-purpose Symbolic Instruction Code) was developed in 1964 by John
Chapter 5 Learning Track 1 20
professional programmers to create operating systems and application software, especially for
PCs.