Transcript slide 2nd Basic computer hardware and software

Hardware and Software
Computer System
Basic Concepts of
Hardware
Computer
Primary Memory
Input
Units
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CPU
(Central Processing Unit)
Output
Units
This model of the typical digital computer is often
called the von Neumann computer.
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Programs and data are stored in the
same memory: primary memory.
The computerThecan
only perform one
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instruction at a time.
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Input Devices
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Input Devices:
devices that input
information into the
computer such as a
keyboard, mouse,
scanner, and digital
camera.
Output Devices
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Output: devices that
output information from
the computer such as a
printer and monitor.
Display monitors: Hi-resolution monitors come in two types:
Cathode ray tube (CRT) - Streams of electrons make
phosphors glow on a large vacuum tube.
Liquid crystal display (LCD) - A flat panel display that
uses crystals to let varying amounts of different colored
light to pass through it.
Developed primarily for portable computers
LCD
CRT
.
Printer
Output Devices
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Audio Output Devices
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Windows machines need special audio card for
audio output.
Macintosh has audio playback built in.
Audio output is useful for:
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Music
 CD player is a computer.
 Most personal computers have CD players that can
access both music CDs and CD-ROMs.
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Voice synthesis (becoming more human sounding.)
Multimedia
Specialized tasks (i.e.: elevator’s floor
announcements)The Computer Continuum
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Central Processing Unit
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CPU (Central Processing Unit) also called the
Microprocessor or “The Brain” of the
Computer.
Processor speed: The speed at which a
microprocessor executes instructions. This is
usually measured in megahertz (MHz).
Brands of Processors include:
 Pentium
 Celeron
 MAC
 AMD
 Cyrix
Central Processing Unit
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Computer chip: also called
the microprocessor may
contain an entire processing
unit.
Computer chips contain
millions of transistors. They
are small pieces of semiconducting material
(silicon).
An integrated circuit is
embedded in the silicon.
Computers are made of
many chips on a circuit
board.
Storage Devices
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Common Basic Technologies for Storing
Binary Information:
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Electronic
Magnetic
Optical
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Data Storage Devices (magnetic and
electronic technologies)
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The hard-drive is a
mechanical storage device
typically located internally.
 Fast recording and
recovery of data
 Large storage capacity
 Magnetic
 Primary storage device for
data and programs
 Speed is measured in
R.P.M.’s
Optical Technology
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Uses lasers to “read” the binary information
from the medium, usually a disc.
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Millions of tiny holes are “burned” into the surface of
the disc.
The holes are interpreted as 1s. The absence of holes
are interpreted as 0s.
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Data Storage Devices (cont’d)
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CD-ROM (compact disk
read only memory)
 Approximately 600
to 700 megabyte of
storage
 An optical device
read by a diode laser
Optical Disks
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Optical Disks: CD-ROM and DVD
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CD-ROM (Compact Disk - Read Only Memory)
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By its definition, CD-ROM is Read Only.
Special CD drives “burn” information into blank CDs.
 Burn: A laser is used to “burn” craters into the surface
to represent a binary 1.
 Two main types of CDs:
 CD-R (Compact Disk - Recordable)
 CD-WR (Compact Disk - ReWritable)
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It takes longer to write to a CD-R than a hard drive.
Special software is needed to record.
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Output Devices
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DVD (Digital Versatile Disk)
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Allows up to 17 gigabytes of storage (from 4.7
GB to 17 GB).
Compatible with older CD-ROM technology.
The four versions of the DVD:
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Magnetic Technology
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Magnetic Technology
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Two parts to most of the magnetic forms of
information storage:
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The medium that stores the magnetic information.
 Example: Floppy disk. Tiny spots on the disk are
magnetized to represent 0s and 1s.
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The device that can “read” that information from the
medium.
 The drive spins the disk.
 It has a magnetic sensing that moves over the disk.
 Performs nondestructive reading.
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Data Storage Devices (Magnetic
technology)
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Floppy diskette is
magnetic storage
device for small
amounts of data
(1.44MB).
FLASH drive is a
compact and portable
electronic storage
device.
 USB (plug and play)
supported
Computer Memory
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Computer memory is binary (0 or 1) (on or off).
The byte is the standard unit of measurement.
A byte is composed of 8 bits (binary digits).
Typical units of measurement:
 1 KB (kilobyte) = 1000 bytes
 1 MB (megabyte) =1000 kilobytes or 1 million
bytes
 1 GB (gigabyte) =1000 megabytes or 1 billion
bytes
Computer Memory (electronic
technology)
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RAM (random access
memory) stores data that
is processing. This type
of memory is erased when
the computer is turned
off.
ROM (read only memory)
contains special
instructions for the
computer to operate.
Cache memory increases
the speed of the processor
by recording and
anticipating instructions.
Storage Devices
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The four most important characteristics of
storage devices:
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Speed and access time
Cost / Removable versus non-removable
Capacity
Type of access
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Speed (Access time)
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Speed (Access time) - How fast
information can be taken from or stored
onto the computer memory device’s
medium.
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Electronic circuits: Fastest to access.
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40 billionths of a second.
Floppy disks: Very slow in comparison.
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Takes up to 1/2 second to reach full speed before
access is even possible.
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Cost
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Cost
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Megabyte: A Million bytes.
Gigabyte: A billion bytes.
Two parts to a removable secondary storage
device:
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The cost of the medium. (Cheaper if bought in quantity)
The cost of the drive.
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Capacity
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Capacity - The amount of information
that can be stored on the medium.
Unit
1 bit
1 nibble
1 byte
1 kilobyte
1 megabyte
Description
Approximate Size
1 binary digit
4 bits
8 bits
1 character
1,024 bytes
1/2 page, double spaced
1,048,576 bytes
500,000 pages
1 million bytes
1 gigabyte 1,073,741,824 bytes
5 million pages
1 billion bytes
1 terabyte 1 trillion bytes
5 billion pages
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Type Access
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Type of Access
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Sequential - Obtained by proceeding through the
storage medium from the beginning until the
designated area is reached (as in magnetic tape).
Random Access - Direct access (as in floppy and
hard disks).
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Maindboard
Graphic User Interface (GUI)
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GUI (Graphic User Interface) is a set of
images and icons seen on the desktop
used to operate a program.
 The GUI makes the programs loaded
on the computer easier to access
and use. Basic Windows GUI
 Icons are small pictures that
represent files, commands, or
windows.
 Windows is a GUI operating
system unlike UNIX, which
uses text commands.
Video Cards
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Video cards plug into the
motherboard and are
used to display video.
VRAM is video memory
that enhances the
refreshment rate of the
image.
Video cards have chipsets
that can increase the
speed of video display.
Ports and Peripherals
 Ports are an interface between the computer and
another peripheral device such as a disk drive,
mouse, printer, modem, monitor, camera, FLASH
drive or keyboard.
Examples:
Serial
Parallel
hot-wire
USB
Ports and Peripherals
 Peripherals are devices
that plug into a
computer and are not
housed internally.
Examples:
Printers
Scanners
Cameras
Resolution
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Resolution refers to the
number of pixels (picture
elements) in the monitor
image.
Increased resolution uses
more computer resources
but increases the visual
clarity of the display.
Resolution
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Screen resolution is measured in
pixel per inch (ppi), and printer
resolution is measured in dots per
inch (dpi).
Computer screen resolution is
approximately 72 ppi.
Width x Height (Pixels) Video
Display
640 x 480 Low Resolution
800 x 600 Medium Resolution
1600 x 1200 High Resolution
LAN and WAN
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LAN: are networks usually
in the same company or
building. The Local Area
Network is connected via
telephone lines or radio
waves. Most LANs connect
workstations.
WAN: are systems of
LANs that are connected.
(Wide-area network)
Bandwidth and Baud Rate
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Bandwidth is how much
information can be
carried in a given time
period (usually a
second) over a wired or
wireless
communications link.
Baud rate is the rate at
which information is
transferred in a
communication channel.
Multitasking and Multiprocessing
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Multitasking is the ability
to execute more than one
task (program) at the
same time. Only one CPU
is used but switches from
one program to another.
In multiprocessing, more
than one CPU is used to
complete a task.
Example: network
rendering.
Multimedia
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Multimedia software
programs include sound,
pictures, video, text, and
hypertext to create
presentations.
Software includes:
PowerPoint
Macromedia Director
FLASH
File Management
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Different programs have different file extensions.
Naming files - avoid the following characters in naming
files:
Examples:
 @
 *
 .
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Understand the parts of a path name.
Example:
Drive designator
C:\MyDocs\trial.php
Directory or folder
File name File extension
File Management
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Saving files - know the difference
between “save” and “save as”.
“Save” will save the open
document over the saved
document while “save as” creates
a new document if you rename
the document. Save often so
work will not be lost.
Exporting – converts a native
format to a non-native file format
used in various software
programs. In vector programs,
file types may be exported.
Software
Operating System
Ex :MS. Windows, Linux, Macintosh
 Aplication Software
Ex :Ms.Office, Macromedia, WinRar
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Any Questions
End Of Sessions