Drives, Memory
& Networking
Due to technology improvements, we are able
to store more in
smaller sized devices.
This allows you to have more and more
portability in an age where
MOBILITY and SMALL is popular.
Why does all this matter?
To understand and appreciate
technological progress!
• Ultrathin, Ultraportable…all because of
state-of-the-art improvements in the size
and capacity of memory, chips, etc.
Do you remember talking
about what this is?
(the thing being loaded off
the airplane)
• This is a 5 Meg Hard
Disk in 1956. In 1956
IBM launched the 305
RAMAC, the first
computer with a hard disk
drive (HDD). The HDD
weighed over a ton and
stored 5 MB of data
(equal to about 3 current
day floppy disks).
• So, start appreciating
your 4 GB IPOD or
memory stick (4,000 MB)!
Apple charges…
•$1799 for the 80 GB (A)
• $3098 for the 64 GB (B)
Why choose A vs. B
A
B
LEFT: 6gb Laptop Drive
RIGHT: Inside view of a 3.5”
(standard size) desktop hard
drive
1GB 3.5” Drive in 1995
18GB 3.5” Drive, SCSI, 1998
Form Factor and Limits
Media:
Floppy, CD
and DVD
• Some of this
media is a
one time use,
like a CDR
• Some is
reusable like
the floppy or
a CD-RW or
DVD-RW
Six hard disk drives with cases opened showing platters and heads; 8, 5.25, 3.5, 2.5,
1.8, and 1 inch disk diameters are represented.
Anatomy of a Hard Drive
RAM
• Manufactures
have learned
how to
compress
more and
more memory
into the
memory sticks
while also
increasing the
speed in which
the date can
be access.
256k
1mb
8mb
64mb
64mb
- Laptop Memory
512mb
1GB Solid State Memory
• Also known as
Secure Data (SD)
• No moving parts
Drives Die
(as found at the Logon Cafe
Computer Store)
always have your work backed up to
TWO locations.
Technology in 10 years.
• This is 35 disks. It would take
1,000 disks to equate the
computer memory picture here, or
the SD card you use for the digital
cameras.
Storage SPACE has increased, but so have FILE sizes.
• 10 years ago, Adobe Premiere would fit on 5 floppy
disks. Today, it takes a DVD with OVER 4,000MB
(4.16gb)
Problem
• Larger, higher res pictures and video are great. But the
infrastructure (i.e. networking) has not kept up.
• Improvements have included the exchange of Copper Wire
networking to Fiber Optic
– A glass fiber designed to guide light along its length by confining as
much light as possible in a propagating form.
Networking Fundamentals
After this lesson, you will be able to:
• Define a computer network.
• Discuss advantages of using a
network.
• Describe a local area network
(LAN) and a wide area
network (WAN).
• Identify the primary difference
between a LAN and a
WAN
What Is a Network?
A system in which a number of independent computers are
linked together to share data and peripherals, such as hard disks
and printers
The key word in the definition is "share.“
Sharing is the purpose of computer networking. The ability to
share information efficiently is what gives computer networking
its power and its appeal.
Stand-alone environment
Why Use a Computer Network?
Sharing information (or data)
• Sharing hardware and software
• Centralizing administration and support
Computer networking arose
as an answer to the need to
share data in a timely fashion.
Network Computers share:
• Documents (memos, spreadsheets, invoices, and so on).
• E-mail messages.
• Word-processing software.
• Project-tracking software.
• Illustrations, photographs, videos, and audio files.
• Live audio and video broadcasts.
• Printers.
• Fax machines.
• Modems.
• CD-ROM drives and other removable drives, such as
Zip and Jaz drives.
• Hard drives.
Sharing Information
The ability to share information quickly and
inexpensively has proven to be one of the most popular
uses of networking technology.
It has been reported that e-mail is by far the number-one
activity of people who use the Internet. Many businesses
have invested in networks specifically to take advantage
of network-based e-mail and scheduling programs.
Sharing Hardware and
Software
Before the advent of networks, computer
users needed their own printers, plotters,
and other peripherals
Sharing a printer
Networks make it possible for several people to share data
and peripherals simultaneously. If many people need to
use a printer, they can all use the printer available on the
network.
Types of Networks
A local area network (LAN) is the basic building block of any
computer network. A LAN can range from simple (two
computers connected by a cable) to complex (hundreds of
connected computers and peripherals throughout a major
corporation). The distinguishing feature of a LAN is that it is
confined to a limited geographic area.
Types of Networks
A wide area network (WAN) has no geographical limit. It
can connect computers and other devices on opposite sides
of the world. A WAN is made up of a number of
interconnected LANs. Perhaps the ultimate WAN is the
Internet.
LAN vs. WAN
• Local Area Network vs.
• Wide Area Network
– A group of computers linked physically by a
network of communication cables
– The difference is muddled these days
because of wireless networking and the vast
number of networks.
– For example, does the WB LAN end with WB,
or is all of BISD the WAN.
Lesson Checkup
•
What is a computer network?
•
What are three advantages of using a computer
network?
•
Give two examples of a LAN configuration.
•
Give two examples of a WAN configuration.
Networking Fundamentals
After this lesson, you will be able to:
• Identify a peer-to-peer network
• Identify a server-based network
• Identify different types of topologies
• Identify different types of transmission media
Re-cap benefits of a Network?
• Sharing information (or data)
• Sharing hardware and software
• Centralizing administration and support
Network Categories
Networks are divided into 2 broad categories:
• Peer-to-peer networks: there are no dedicated servers, and
there is no hierarchy among the computers. All the
computers are equal and therefore are known as peers. Each
computer functions as both a client and a server, and there is
no administrator responsible for the entire network. The user
at each computer determines what data on that computer is
shared on the network.
Network Categories
Peer-to-peer network
Network Categories
• Server-based network
In an environment with more than 10 users, most
networks have dedicated servers. A dedicated server is
one that functions only as a server and is not used as a
client or workstation. Servers are described as
"dedicated" because they are not themselves clients, and
because they are optimized to service requests from
network clients quickly and to ensure the security of
files and directories. Server-based networks have
become the standard models for networking.
Network Categories
Server-based network
Comparison of Network
Categories
Peer-to-Peer Network
Server-Based Network
Good for 10 or fewer
computers
Security established by the
user of each computer
Individual users responsible
for their own administration;
no full-time administrator
necessary
Limited only by server and
network hardware
Extensive and consistent
resource and user security
Centrally located for network
control; requires at least one
knowledgeable administrator
Network Topology
The term topology, or more specifically, network
topology, refers to the arrangement or physical
layout of computers, cables, and other
components on the network.
Network Topology
All network designs stem from four basic
topologies:
Bus
Star
Ring
Mesh
Bus Topology
The bus topology is often referred to as a "linear
bus" because the computers are connected in a
straight line. This is the simplest and most common
method of networking computers.
Star Topology
The star network offers the advantage of centralized resources
and management. However, because each computer is
connected to a central point, this topology requires a great deal
of cable in a large network installation. Also, if the central
point fails, the entire network goes down.
Ring Topology
The ring topology connects computers on a single
circle of cable. Unlike the bus topology, there are
no terminated ends. The signals travel around the
loop in one direction and pass through each
computer. The failure of one computer can have an
impact on the entire network.
Mesh Topology
A mesh topology network offers superior redundancy and
reliability. In a mesh topology, each computer is connected to
every other computer by separate cabling. If one cable fails,
another will take over the traffic. While ease of
troubleshooting and increased reliability are definite pluses,
these networks are expensive to install because they use a lot
of cabling.
Transmission Media
• Coaxial cable
• Twisted-pair
• Fiber-optic cable
• Wireless
Summary
•Identify a peer-to-peer network
• Identify a server-based network
• Identify different types of topologies
• Identify different types of transmission media