CIS070
Fundamentals
of Computing
Theory Unit
Part 1
What is a computer?
It is an electronic device that:
Receives data (input)
Processes data (processing)
Stores data (output)
Produces a result (storage)
It performs only three operations:
Arithmetic operations (+ - / * ^ )
Logical comparison of values ( = > < )
Storage and retrieval of operations
Classifying Computers - Supercomputer
Largest and ultrafast computers.
Used by government agencies,
the scientific community, and
large corporations with
tremendous volumes of data to
be processed.
Much faster than any other type
of computer.
Cost can from $1 million to $20
million.
Classifying Computers – Mainframe
Smaller and less powerful than
supercomputers, but still large
compared to personal computers.
Used by larger institutions and
government installations.
Used for centralized storage,
processing, and management of very
large amounts of data.
Cost hundreds of thousands of dollars.
Usually kept in controlled climate.
Classifying Computers – Minicomputer
Larger than personal microcomputers
and basically have the same
capabilities.
The cost is much higher.
Would use if there are many users
connected to them, and large
amounts of data needed to be
processed.
In recent years, the minicomputer
market has declined.
Classifying Computers – Microcomputer
Also called a PC, personal computer or
desktop computer.
Type of computer used at home or at the
office by one person.
Priced anywhere from $300-$3,000.
Notebook (laptop) computer has the same
capabilities as the desktop; however, much
smaller and usually more expensive.
Because of its size, it is portable and can
run on power from an electrical outlet or
batteries.
Often equipped with wireless connection
so they can be used away from a desk.
Classifying Computers – Tablet PC
Type of notebook computer that has an LCD screen
that the user can write on using a special-purpose pen
or stylus.
You can also rotate the screen 180 degrees and lay it
flat over the keyboard for a more comfortable reading
and writing experience
Other Computing Devices - PDA
PDA (personal digital assistant) – also
known as a palm-top.
Smaller than a notebook.
Limited capabilities.
Touch-sensitive screen accepts characters
drawn with your finger or a special stylus.
Becoming a common tool for business and
professional people, as well as students.
Other Computing Devices
Cell phones
Calculators
Digital cameras
Dishwashers
Refrigerators
Cars and trucks
Various media players
A computer system consists of 4 parts:
Hardware – the tangible, physical
equipment that can be seen and touched.
Software – the intangible set of
instructions that tells the computer what
to do.
Data – facts entered into a computer
(text, numbers, sounds, images)
People – users of the computers who
enter data and use the output.
Just about all computers, regardless of size, take raw
data and change it into information you can use. The
process involves input, process, output, and storage.
You input data with some type of input device.
The computer processes it to turn it into
information.
You output the information to some type
of output device.
You store it for later retrieval.
Input, output, and processing devices grouped
together represent a computer system.
INPUT Devices - Keyboards
Most common input device is a keyboard.
Provides a set of alphabetic, numeric, punctuation,
symbolic, and control keys.
INPUT Devices – Pointing Devices
Mouse – control the pointer on the screen. Use to have
a mechanical ball underneath that rolled on a flat surface.
Now, most are optical mouse, which operates with a
sensing device in place of the ball. Can be wireless.
Trackball - designed as an alternative to the mouse. It
is almost an upside-down mouse; it is stationary and
contains a movable ball that you rotate using your fingers
to move the mouse cursor on the screen.
Joystick - transfers movements you make with the
device into movements on your computer screen. It is
used to simulate arcade-style play for computer games.
INPUT Devices – Voice Recognition
Voice recognition devices are used to “speak”
commands into the computer and to enter text.
To use voice recognition, you will need:
Hardware
Software
Voice recognition
technology has enabled
disabled persons to
communicate with a
computer using only
voice commands.
INPUT Devices – Scanners
Scanners are devices that can change images into
codes for computer input.
There are various sizes and types of scanners.
Image scanners – convert images into electronic form
that can be stored into a computer’s memory. The
image can then be manipulated.
Flatbed scanner is the most
common in offices.
Hand-held scanners - device is
moved by hand.
INPUT Devices – Scanners (cont’d)
Bar code scanners – reads bar lines that are
printed on products.
Magnetic scanners – read encoded
information on the back of credit cards.
INPUT Devices – Other
Graphics Tablets – also called a
digitizing tablet – is a flat drawing
surface on which the user can
draw.
Touch Display Screen –
displays shapes or text and you
use your finger to “point” to the
desired object. Very user friendly.
INPUT Devices – Other
(cont’d)
Digital Cameras – pictures
are stored in the camera’s
memory and can be
transferred to the computer’s
memory.
Video Input – Images
captured with a digital
camcorder or from a
VCR/DVD player and
transferred to a computer.
Capture DVD-quality video
from any camcorder, TV or
VCR with Dazzle Digital
Video Creator
INPUT Devices – Other
Digital Pen
Data Glove
Head Devices
(cont’d)
OUTPUT Devices
Output devices display information.
Examples of output are printed text,
spoken words, music, pictures, or graphics.
OUTPUT Devices - Monitors
Monitors are called video display screens
because images are displayed on the screen.
Factors that influence the quality of a monitor
are:




CRT versus LCD
Screen size
Resolution
Dot pitch
OUTPUT Devices – Monitors
CRT – Today, one of the most commonly used
technologies for computer monitors. CRT, or
Cathode Ray Tube, is a technology much like
what you will find on most TVs. CRT monitors
are bulky and very heavy.
Flat Panel / LCD (Liquid Crystal Display) monitors are similar to what is found on portable
computers. LCD monitors overall generally
display much sharper of an image, are lighter
and more space efficient; however, they are
much more of an expensive solution for desktop
displays.
OUTPUT Devices – Monitors
When considering purchasing a monitor utilizing the CRT technology it is
important to consider the following:
Dimensional Size –Monitors are available in 15",17", and 19“ -
larger is generally more expensive. The larger the screen, the more
amount of viewable space you will be able to work with. Users who
plan on using the computer for graphics should use at least a 21"
monitor.
Viewable Size - The viewable size of the monitor is a very
important consideration and can varies by manufacturer. The
viewable size is the size of viewable area and not the complete
monitor. While a monitor may be labeled a 15- or 17-inch unit, the
actual image size ("viewable area") may be an inch or two smaller.
The "viewable screen area" measurement is the distance from the
top left corner to the bottom right corner of the screen.
DOT PITCH
Dot Pitch measurement is found on most monitors - defines the
amount of space (in millimeters) that separates two adjacent pixels
that are the same color. The smaller the Dot Pitch, the sharper the
image. The recommended dot pitch be no bigger than 0.25.
RESOLUTION
The maximum resolution is the amount of pixels that can be
displayed horizontally x vertically. Refers to the sharpness of an
image.
These sizes can be debated but are the standard and most easily
viewed resolutions.
15" – 800 x 600 / 1,024 x 768
17" – 1,280 x 1,024
19" – 1,280 x 1024
21" - 1,600 x 1,200
OUTPUT Devices – Printers
Printers are used to produce a paper or hard copy of
the processing results.
There are several types of printers with tremendous
differences:
Speed - Printer speed is measured in pages per minute (ppm).
The number of pages a printer can print per minute varies for
text and graphics. Graphics print slower than regular text.
Print quality - Print quality if measured in dots per inch (dpi).
This refers to resolution.
Price – The price includes the original cost of the printer as
well as what it costs to maintain the printer. A good quality
printer can be purchased very inexpensively; a high-output
system can cost thousands of dollars. What is the cost of the
ink cartridges or toners?
Two basic types of printers:
Laser
Produce images using the same
technology as copier machines.
The image is made with a
powder substance called toner.
High-quality output and faster.
Cost more than inkjet.
Inkjet
Least expensive.
Produce excellent color
printing.
Color is sprayed onto the
paper in the form of dots.
Slower than laser printers.
All-in-one Printers
Combines printer, scanner, copier, and
fax capabilities.
OUTPUT DEVICES: Plotters
Plotters are printers that produce high-quality images
by physically moving ink pens over the surface of the
paper.
They can draw complex line art, including text, but do
so very slowly because of the mechanical movement of
the pens.
Great for creating computer-generated maps, charts,
and architectural plans.
OUTPUT DEVICES: Other
Speakers – used to listen to computergenerated sound.
LCD projectors – enables a presenter to
project the computer’s screen display onto a
screen similar to one used with a slide
projector.
White board (also call a smart board) - The
touch-sensitive display connects to your
computer and digital projector to show your
computer image. You can then control
computer applications directly from the
display, write notes in digital ink and save
your work to share later.
Storage Devices
If you want to keep a permanent copy of your
data, you must store it on some type of storage
medium.
Device is capable of retaining data even when
electrical power is switched off.
Storage devices are categorized by the method
they use to store date.
Storage Devices – Floppy Diskette
Usually called diskettes.
Most are 3 ½” in size.
They have a storage capacity
to hold 1.44 MB or more of
data.
A megabyte (MB) is 1,048,576
bytes.
A kilobyte (KB) is 1,024 bytes.
These measurements are often
rounded off so that a kilobyte
is defined as 1000 bytes and a
megabyte as 1,000 kilobytes.
Storage Devices – Zip Disk/Drive
A Zip disk can hold as much as 70
floppy diskettes.
Holds about 100-750 MB of data.
They costs approximately $10-$15 each.
Size is 3 inches.
Zip drive houses a zip disk. You must
have a zip drive to use a zip disk.
The drive cost approximately $80-$180
each.
Storage Devices – Compact Disc
CD-ROM ( compact disc read only memory) data
recorded on them can be read many times, but it cannot
be changed.
CD-R (Compact Disc-Recordable) – “write-once”
technology; you can’t erase or write over it.
10-pack runs approximately $7
700MB - 80 minutes
CD-RW (Compact Disc ReWritable) – allows data that
have been saved to be erased and rewritten.
10-pack runs approximately $13
650-700MB and 74-80 minutes
CD-RW Drive (also called burners)
Internal CD-RW drive – approximately $40
External CD-RW drive – approximately $79
Storage Devices – DVD
(digital versatile disk)
DVDs come in two standards:
DVD+ (plus)
DVD+R – recordable one time; read many times ($9-$12)
DVD+RW – can be rewritten many times ($18-$21)
4.7GB and 120 minutes; 10-pack approx. $9-$11
Supported by Philips, Sony, Dell, Ricoh, Hewlett-Packard, Yamaha
DVD– (dash)
DVD-R you can write one time; read many times ($9-$12)
DVD-RW – can write, erase, and read many times ($18-$21)
4.7GB and 120 minutes
Supported by Panasonic, Toshiba, Apple, Hitachi, NEC, Pioneer,
Samsung, and Sharp
Storage Devices – DVD-RAM
Enables computer users to burn DVDs
containing up to nearly 5 GB of data.
Can be recorded and erased
repeatedly but are only compatible
with devices manufactured by the
companies that support the DVD-RAM
format.
Can be rewritten 100,000 times (100
times more than either DVD-RW or
DVD+RW)
Costs approximately $5-$7 each
Storage Devices – JUMP Drive
Also called flash drive, thumb drive, pen
drive
USB connection Memory size from 64 MB-4 GB
Range in price from $10 - $100
(depending on memory size)
Storage Devices – Network Drive
A network drive is located on another computer or
sever that provides space you can use for storage.
It might appear as the Q:\ drive or S:\ drive.
This is a “picture” of the network
drives available here on the CCC
campus.
Students have access only to the “J”
drive. This is where instructors
sometimes put files for students.
The “K” and “L” drives are for the
faculty and staff here on campus.
Note the icon for a network drive.
Storage Devices
Virtual and Internet Storage
Some companies provide internet-based storage (also
called remote file storage or virtual hard drive).
Internet storage is a simple means of sharing files.
It is also used for off-site backups of data.
Most sites that offer this service charge a modest fee;
and some will provide either a more restricted free
service or a limited free trial.
Example: Drive HQ - http://www.drivehq.com/
Storage Devices
Virtual and Internet Storage (cont’d)
Example: http://www.i2drive.com