Computer Concepts - Illustrated
Introductory, Seventh Edition
UNIT D:
Digital Electronics and File
Management
Objectives
Discuss data representation
Explore chips
Discuss processors
Explore computer memory: RAM
Examine computer memory
Explore computer files
Computer Concepts – Illustrated Introductory, Seventh Edition
Objectives
Examine file locations
Explore file management
Open and save files
Talking points: Is your computer
making you sick?
Computer Concepts – Illustrated Introductory, Seventh Edition
Discussing Data Representation
Data representation - form in which
data is stored, output, and transmitted
Digital data
 Text, numbers, graphics, sound, and
video converted into discrete digits: 0s
and 1s
Analog data
 Represented using infinite scale of
values
Computer Concepts – Illustrated Introductory, Seventh Edition
Discussing Data Representation
Bit - each 1 and 0 in electronic
signal




Byte - eight bits
Kilobit - 1,024 bits
Kilobyte is 1,024 bytes
Megabit, megabyte, gigabit, gigabyte
Computer Concepts – Illustrated Introductory, Seventh Edition
Discussing Data Representation
Numeric data - numbers that
represent quantities that might be
used in arithmetic operations
Binary system (base 2) allows
representation of any number using
just 1s and 0s
Character data - letters, symbols, and
numerals that will not be used in
arithmetic operations
Computer Concepts – Illustrated Introductory, Seventh Edition
Discussing Data Representation
Comparing decimal and
binary number systems
Computer Concepts – Illustrated Introductory, Seventh Edition
Discussing Data Representation
Images must be digitized into 1s
and 0s for computer to understand
them
 Photos, pictures, line art, and graphs
Computer Concepts – Illustrated Introductory, Seventh Edition
Discussing Data Representation
Sound waves must be digitized for
computer use
Computer Concepts – Illustrated Introductory, Seventh Edition
Exploring Chips
Integrated circuit (chip) - most significant
technology that made PCs possible
 Thin slice of semiconducting material (silicon or
germanium)
 Packed with microscopic circuit elements over which bits
travel
Computer Concepts – Illustrated Introductory, Seventh Edition
Exploring Chips
Integrated circuit - in computers,
PDAs, cell phones, most electronics
Chips connect to computer’s main
circuit board (motherboard)
Some are plugged into slots on board
or special sockets or connectors
Others soldered into place
Computer Concepts – Illustrated Introductory, Seventh Edition
Exploring Chips
Electronic components
Computer
PDA
Computer Concepts – Illustrated Introductory, Seventh Edition
Cell Phone
Exploring Chips
Chips protected by protective
carrier or chip package
 Carriers vary in shape and size
• DIP (dual inline package)
• DIMMs (dual inline memory modules)
• PGA (pin-grid array)
Computer Concepts – Illustrated Introductory, Seventh Edition
Exploring Chips
Processor (microprocessor)
 Complex integrated circuit
 Contains as many as 400 million
components
 Most important and usually most
expensive part of computer
Producers of processors
 Intel
 AMD
Computer Concepts – Illustrated Introductory, Seventh Edition
Exploring Chips
Possible to upgrade processor in computer
 Owners seldom do
 Cost of latest processor more than halfway
to new computer
 Processor operates at full efficiency only if
all components of computer can handle
processor’s speed
Computer Concepts – Illustrated Introductory, Seventh Edition
Discussing Processors
Central processing unit
(CPU)
 Single chip
 Circuitry performs central
processing tasks of computer
Software can identify
computer’s CPU and its
specifications
Computer Concepts – Illustrated Introductory, Seventh Edition
Discussing Processors
Performance - affected by several
factors
 Clock speed
 Bus speed
 Word size
 Cache size
 Instruction set
 Processing techniques
Computer Concepts – Illustrated Introductory, Seventh Edition
Discussing Processors
Clock speed
 Pace for executing instructions
Cycle
 Smallest unit of time processor can
recognize
FSB (front side bus)
 Circuitry that transports data to and from
processor
Computer Concepts – Illustrated Introductory, Seventh Edition
Discussing Processors
HyperTransport
 Technology which helps increase speed
of data moving in processor
Cache (RAM cache or cache
memory)
 High-speed memory processor can
access more rapidly than memory
elsewhere
Computer Concepts – Illustrated Introductory, Seventh Edition
Discussing Processors
Word size
 Number of bits processor can manipulate at one time
Source code
 Human-readable version of program
Compiler
 Converts all statements in program in single batch
 Resulting in collection of instructions called object code
Interpreter
 Converts and executes one statements at a time while
program is running
Computer Concepts – Illustrated Introductory, Seventh Edition
Discussing Processors
Computer Concepts – Illustrated Introductory, Seventh Edition
Discussing Processors
Instruction set used by affects
performance
CISC (complex instruction set
computer)
RISC (reduced instruction set
computer)
CISC technology used in most PCs
Computer Concepts – Illustrated Introductory, Seventh Edition
Discussing Processors
Processing technique in processor also
affects performance
 Serial processing
• Processor must complete entire instruction cycle
before beginning new instructions
 Pipelining
• Processor can start second instruction before
finishing first
 Parallel processing
• Multiple instructions at same time
 Hyper-Threading
• Allows execution of multiple instructions in parallel
Computer Concepts – Illustrated Introductory, Seventh Edition
Exploring Computer Memory: RAM
RAM (random access memory)
 Temporary holding area for data,
program instructions, and operating
system
 Usually several chips or small boards
that plug into motherboard
 Next to processor, RAM is one of most
expensive computer components
Computer Concepts – Illustrated Introductory, Seventh Edition
Exploring Computer Memory: RAM
RAM is waiting room for processor
Computer performance directly depends on
RAM that is available for applications, data,
and operating system
Computer Concepts – Illustrated Introductory, Seventh Edition
Exploring Computer Memory: RAM
Capacitors
 Electronic parts that hold data
• Charged capacitor = 1
• Discharged capacitor = 0
Computer Concepts – Illustrated Introductory, Seventh Edition
Exploring Computer Memory: RAM
SDRAM - fast and relatively
inexpensive
 Used in most PCs today
RDRAM - about 8 times faster,
but more expensive
Computer Concepts – Illustrated Introductory, Seventh Edition
Exploring Computer Memory: RAM
RAM stores data in circuitry
connected to motherboard
 Hard drive stores data on magnetic
media
RAM - temporary storage
 Hard drive more permanent
Computer Concepts – Illustrated Introductory, Seventh Edition
Exploring Computer Memory: RAM
Today’s PCs typically feature 512
MB and 2 GB of RAM
RAM can be added up to limit set
by manufacturer
Faster RAM means faster
performance
Computer Concepts – Illustrated Introductory, Seventh Edition
Examining Computer Memory
Virtual memory
 Can store parts of program or data file until
needed
 Helps take some load off RAM
Boot process
 Sequence of events between time you turn
computer on and time that it is ready for use
 Stored on ROM (read only memory)
Computer Concepts – Illustrated Introductory, Seventh Edition
Examining Computer Memory
ROM BIOS (basic
input/output system)
 Holds configuring
information which
cannot be stored on
RAM because it would
be lost when computer
is turned off
Computer Concepts – Illustrated Introductory, Seventh Edition
Examining Computer Memory
EEPROM (electronically erasable
programmable read-only
memory)
 Stores and updates basic system
information
 More permanent than RAM, less than
ROM
 Nonvolatile chip requires no power to
store information
Computer Concepts – Illustrated Introductory, Seventh Edition
Examining Computer Memory
Access EEPROM setup

Hold down F1 key as computer boots
Computer Concepts – Illustrated Introductory, Seventh Edition
Exploring Computer Files
File - named collection of data that
exists on storage medium
 hard drive, solid-state storage device, CD,
DVD, or tape
Computer Concepts – Illustrated Introductory, Seventh Edition
Exploring Computer Files
Filename
 Unique set of characters and numbers
 Identifies file and should describe
contents
Filename has two parts
 Filename
 Filename extension
Computer Concepts – Illustrated Introductory, Seventh Edition
Exploring Computer Files
Filename extension (file
extension)
 Further describes file contents
 Separated from main filename by period
File format
 Arrangement of data in file and coding
scheme used to represent data
Computer Concepts – Illustrated Introductory, Seventh Edition
Exploring Computer Files
Native file format
 Format used by software program to store data
User does not decide file extension
 File extension can be changed, really shouldn’t
• Extension usually related to file format
Files can be converted from one
format to another
Computer Concepts – Illustrated Introductory, Seventh Edition
Exploring Computer Files
Converting a File
Computer Concepts – Illustrated Introductory, Seventh Edition
Exploring Computer Files
File size
 Measured in bytes, kilobytes, or
megabytes
 Knowing file size can be important
• Especially if sending e-mail attachment
File date
 Date on which file was saved or last
modified
Computer Concepts – Illustrated Introductory, Seventh Edition
Examining File Locations
User decides where files are stored
Windows OS labels storage devices with
letters
 A: and C:
Computer Concepts – Illustrated Introductory, Seventh Edition
Examining File Locations
Folder
 Logical representation of where files are
stored
 Each folder is named, can hold many
files
 Folders can be created within folders
Computer Concepts – Illustrated Introductory, Seventh Edition
Examining File Locations
Directories and subdirectories are
synonymous with folders and files
 Terms used because OS maintains list
of files called ‘directory’
• Main directory on disk is root directory
• Root directory subdivided into smaller
subdirectories
Computer Concepts – Illustrated Introductory, Seventh Edition
Examining File Locations
Filing cabinet popular metaphor
for computer
storage
Tree structure storage metaphor
based on
hierarchical
Computer Concepts – Illustrated Introductory, Seventh Edition
Examining File Locations
File specification (path)
 Computer file’s location - begins with
drive letter and is followed by
• Folder(s)
• Filename
• File extension
Computer Concepts – Illustrated Introductory, Seventh Edition
Examining File Locations
Disk partition
 Section of hard drive treated as
separate storage unit
 Many computers are configured with
one partition which holds OS, programs,
and data
 Possible to create more than one hard
drive partition
Computer Concepts – Illustrated Introductory, Seventh Edition
Exploring File Management
Good file management helps create,
open, save, delete, and rename files
File management utilities - available to
help keep track of program and data
files
 Most useful when you have logical organization
plan
 Gives big picture of files stored on storage media
 Help organize and manipulate files logically
• Windows Explorer is Windows file management utility
Computer Concepts – Illustrated Introductory, Seventh Edition
Exploring File Management
Windows file management utility
Computer Concepts – Illustrated Introductory, Seventh Edition
Exploring File Management
Windows Explorer tools
 Selected file can be copied, moved,
renamed, or deleted as needed
 Menu bar and address bar help locate
and organize files and folders
 Search and organize commands
 E-mail files or create CDs or DVDs
containing files
 File sharing
 View commands customize display
Computer Concepts – Illustrated Introductory, Seventh Edition
Exploring File Management
Windows Explorer tools
Computer Concepts – Illustrated Introductory, Seventh Edition
Exploring File Management
Windows provides
series of default folders
 Documents, Pictures, Music
 When Windows recognizes
file extension as document
or picture, it opens
Document or Picture folders
accordingly
Computer Concepts – Illustrated Introductory, Seventh Edition
Exploring File Management
Desktop search tools help find
and access information in
 E-mails
 Web pages
 Contact lists
Computer Concepts – Illustrated Introductory, Seventh Edition
Opening and Saving Files
Application
software provides
access to file
management tasks
through Save,
Save As, and
Open dialog boxes
Computer Concepts – Illustrated Introductory, Seventh Edition
Opening and Saving Files
Computer Concepts – Illustrated Introductory, Seventh Edition
Opening and Saving Files
What can be done with files and
folders
Computer Concepts – Illustrated Introductory, Seventh Edition
Opening and Saving Files
Save or Save As?
Computer Concepts – Illustrated Introductory, Seventh Edition
Opening and Saving Files
Tips for managing files
 Use descriptive names
 Maintain file extensions
 Group similar files and consider using
default files in Windows
 Do not mix data files and program files
 Do not store data or program files in root
directory
Computer Concepts – Illustrated Introductory, Seventh Edition
Opening and Saving Files
More tips for file management
 Be aware of storage locations
 Organize folders from top down
 Access files from hard drive
 Follow copyright rules
 Delete or archive files longer needed
Computer Concepts – Illustrated Introductory, Seventh Edition
Talking Points:
Is your computer making you sick?
How does digital lifestyle affect
health of nation and world?
 Radiation risks
 Repetitive stress
injuries
Computer Concepts – Illustrated Introductory, Seventh Edition
Talking Points:
Is your computer making you sick?
Most repetitive stress injuries can be
avoided by following ergonomic guidelines
Computer Concepts – Illustrated Introductory, Seventh Edition
Talking Points:
Is your computer making you sick?
Other health issues
 Eye strain
 Back pain
 Sedentary lifestyle
Computer Concepts – Illustrated Introductory, Seventh Edition