2. 5-2
INTRODUCTION
• Information technology (IT)
– computer-based ______
– that people use
– to support the information-processing needs of
an ______________
• Computer system consists of
– Hardware - consists of the physical devices
associated with a computer system
– Software - the set of ____________ that the
hardware executes to carry out specific tasks
3. 5-3
HARDWARE BASICS
• Computer
– an electronic device operating under the control of
instructions stored in its own ___________ that can
accept, manipulate, and store data
• Hardware components include:
1. Central processing unit (CPU)
2. Primary storage
3. ____________ storage
4. Input device
5. Output device
6. Communication device
4. 5-4
Central Processing Unit (CPU)
• CPU (or _________________)
– Executes the program (software) instructions
– Coordinates all the other hardware devices
• Parts of the CPU
– Control unit
• interprets software instructions
• literally tells the other hardware devices what to do
– Arithmetic-logic unit (ALU)
• Performs ___________ operations
• Performs logic operations (such as sorting and
comparing numbers)
5. 5-5
Central Processing Unit
• The number of CPU cycles per second
determines the speed of a CPU
– Megahertz (MHz) - the number of _________ of
CPU cycles per second
– Gigahertz (GHz) - the number of _________ of
CPU cycles per second
6. 5-6
Central Processing Unit
• CPU speed factors
– Clock speed—rate at which instructions are performed
– Word length—number of bits processed at each cycle
– _____ width—number of “lanes” for signals to travel
– Chip line width—distance between transistors in a chip
• Binary digit (bit)
– the smallest unit of information that a computer can
process
• Byte
– a group of ______ bits representing one natural
language character
– 01000001 = A
7. 5-7
Primary Storage
• Primary storage
– the computer’s main memory
– directly accessible to the _____
– consists of
• random access memory (RAM)—high speed
• ________ memory—very high speed
• read-only memory (ROM)—fixed set of instructions
8. 5-8
Random Access Memory (RAM)
• Random access memory (RAM)
– the computer’s primary working memory
• RAM stores
– Program instructions
– ______
• Characteristics of RAM
– High-speed access
– Volatility (when _______ goes off)
9. 5-9
Read-Only Memory (ROM)
• Read-only memory (ROM) - the portion
of a computer’s primary storage that does
not lose its contents when one switches
off the power
– Flash memory
– Memory card
– Memory stick
10. 5-10
Secondary Storage
• Secondary storage - consists of equipment
designed to store large volumes of data for
long-term storage
– Megabyte (MB or M or Meg) - roughly 1 million
bytes
– Gigabyte (GB) - roughly 1 billion bytes
– Terabyte (TB) - roughly 1 _______ bytes
11. 5-11
Magnetic Medium
• Magnetic medium - a secondary storage medium
that uses magnetic techniques to store and
retrieve data on disks or tapes coated with
magnetically sensitive materials
– Magnetic tape - an older secondary storage medium
that uses a strip of thin plastic coated with a
magnetically sensitive recording medium
– Hard drive - a secondary storage medium that uses
several rigid disks coated with a magnetically sensitive
material and housed together with the recording heads
in a hermetically sealed mechanism
12. 5-12
Other Media
• Optical medium:
– Compact disk-read-only memory (CD-ROM)
– Compact disk-read-write (CD-RW) drive
– ________ video disk (DVD)
– DVD-ROM drive
– Digital video disk-read/write (DVD-RW)
• Flash memory
– Electrically __________ Programmable
Read-Only Memory (EEPROM)
– ‘flash drives’
13. 5-13
Input Devices
• Input device - equipment used to
capture information and commands
– Manual input devices
• Joystick
• Keyboard
• Microphone
– Automated input devices
• Bar code scanner
• Digital camera
• Magnetic ____ character reader
14. 5-14
Output Devices
• Output device - equipment used to see,
hear, or otherwise accept the results of
information processing requests
– Cathode-ray tube (CRT)
– ________ crystal display (LCD)
– Laser printer
– Ink-jet printer
– Plotter
15. 5-15
Communication Devices
• Communication device - equipment
used to send information and receive it
from one location to another
– Dial-up access
– Cable
– Digital subscriber line (DSL)
– Wireless
– Satellite
17. 5-17
SOFTWARE BASICS
• System software - controls how the various
technology tools work together along with the
application software
– __________ system software
• Windows, Mac, Linux
– Utility software
• Backup
• Recovery
• Security
– Application software
18. 5-18
Application Software
• Most common types of application software
– Browser: for surfing the Internet
– Database management: accessing large
amounts of data
– E-mail: communication
– Presentation graphics: slide shows
– Spreadsheet: performing complex calculations
– Word processing: creating documents
