Unit 4 :
System Software
Operating Systems
3 main functions :
•
Provide user interface
•
Load and Run programs
Manage computer's resources
•
Graphical User Interface
Provides interface to communicate with computer
Resource Management
•
Input and
Output
•
File Management
Memory Management
°
•
Process Management
Drivers
(inks hardware to the software to operate
Control panel and Task OS and utilities
manager manages
Utilities
•
De fragmentation
-
:
Rearranges fragmented data on HDD
Updating
•
•
Archive
Backup
•
software Distribution
•
Proprietary : Cannot be freely distributed or copied
Free and Open Source Able to modify and redistribute software
•
:
Firewall
Designed to permit I deny network transmissions
, Unit 5 :
Computer Networks
What is a network
Consists of devices called channel
two or more nodes
through communication
node device connected to network
any
:
a
communication channel :
can be bounded or unbounded .
A network that exists in a
geographical are is called
a local area network ( LAN)
Nodes
Nodes in a network can be :
•
Device that users use
•
Switch : Connects nodes in network
•
Router
•
Devices to provide a service
Communication Media
3 parts of network :
1 Hardware that
. acts as sender
2 . Hardware that is reciever
3 .
Connection between source and destination
Communication channel has bandwidth
↳
Usually measured in Kbps Mbps G- tops
, ,
Bounded Media
Unshielded Twisted Pair ( UTP)
Most common bounded media
cabling
Consists of pairs of twisted wires
RJ45 connector
Problems
w/ copper
cables
Attenuation :
Signal loses strength over distance
Electro -
Magnetic Interference :
Signals can be disrupted
Eavesdropping Signal be :
can
intercepted
Crosstalk Signals adjacent wires
:
in can interfere
System Software
Operating Systems
3 main functions :
•
Provide user interface
•
Load and Run programs
Manage computer's resources
•
Graphical User Interface
Provides interface to communicate with computer
Resource Management
•
Input and
Output
•
File Management
Memory Management
°
•
Process Management
Drivers
(inks hardware to the software to operate
Control panel and Task OS and utilities
manager manages
Utilities
•
De fragmentation
-
:
Rearranges fragmented data on HDD
Updating
•
•
Archive
Backup
•
software Distribution
•
Proprietary : Cannot be freely distributed or copied
Free and Open Source Able to modify and redistribute software
•
:
Firewall
Designed to permit I deny network transmissions
, Unit 5 :
Computer Networks
What is a network
Consists of devices called channel
two or more nodes
through communication
node device connected to network
any
:
a
communication channel :
can be bounded or unbounded .
A network that exists in a
geographical are is called
a local area network ( LAN)
Nodes
Nodes in a network can be :
•
Device that users use
•
Switch : Connects nodes in network
•
Router
•
Devices to provide a service
Communication Media
3 parts of network :
1 Hardware that
. acts as sender
2 . Hardware that is reciever
3 .
Connection between source and destination
Communication channel has bandwidth
↳
Usually measured in Kbps Mbps G- tops
, ,
Bounded Media
Unshielded Twisted Pair ( UTP)
Most common bounded media
cabling
Consists of pairs of twisted wires
RJ45 connector
Problems
w/ copper
cables
Attenuation :
Signal loses strength over distance
Electro -
Magnetic Interference :
Signals can be disrupted
Eavesdropping Signal be :
can
intercepted
Crosstalk Signals adjacent wires
:
in can interfere
