Unit 1 computer types network





A computer is an electronic device that
receives data (input), processes data,
stores data, and produces a result
(output).
It performs only three operations
 Arithmetic

operations (adding, subtracting,
dividing, and multiplying.)
 Logical comparison values (equal to, greater
than)
 Storage and retrieval operations


Big deal..? Why and how do you use
computers and which kinds do you use?


Type

Size

Power

Purpose

Supercomputers

Largest

Fastest processing
speeds compared
to other
computers

•Cost

Mainframe

computers

Large

Less powerful
than
supercomputers
but large
compared to
personal
computers

•Can

Minicomputers

Larger than
microcomputers
but smaller than
mainframe

computers

Same as
microcomputers

•Used

Microcomputers
and notebook
computers

Fits on a
desktop

Not meant for
large amount of
data

•Writing


can be several
million dollars
•For corporations with
lots of data to be
processed
cost hundreds of
thousands of dollars
•Performs centralized
processing tasks for
many users

for companies with
many users and large
amounts of data and can
run on any computer
hardware
papers, tracking
finances, playing games,
connecting to the
Internet.






Role: The CPU also called microprocessor,
or brain of the computer, contains millions
of switches and pathways to help the
computer make decisions. The switches
control the flow of electricity as it travels
across the pathways. Computer programs
are special instructions written to tell the
computer which switches to turn on or off.
Speed: deciding factor on which computer
to purchase. The system clock is an
electronic pulse used to synchronize the
processing and determines the speed of the
processor, measured in megahertz. The
higher MHz the faster the computer.









Computers only understand machine
language, or binary, which is ones and zeros.
Through the pathways and by turning switches
on and off the CPU processes ones and zeros
When electricity is present it represents a one.
The absence of electricity represents a zero.
Coding Systems such as American Standard
Code for Information Interchange (ASCII)
determines which combination of zeros and
ones represents the letter A or the number 1.
Each one or zero is a bit, and eight bits or
combinations of ones and zeros represents a
byte.






RAM – (random access memory) often
referred to as main memory is the data,
information, and program instructions
temporarily stored on a RAM chip. If there
is a power loss this is the information lost.
The amount of Ram can help increase
how fast the computer processes data.
ROM – (read only memory) stores specific
instructions needed for computer
operations. The computer can read from a
ROM chip but cannon write or store data
on this chip.




Secondary storage devices are used
when you want to store a file or
information permanently
 Computer’s
 Floppy

hard disk drive

disk
 CD-ROM
 Thumb drive





A network connects one computer to
other computers and peripheral devices
Allows computers to share:
 Data


– special group projects, databases,

etc.
 Hardware – printers or scanners
 Software – instead of purchasing programs
for each individual computer, a site license
can be purchased for the number of users
and it is less expensive
 Files – collaborative, allows users to work
together