MOTHERBOARD BUS
-set of wires that allows one part of the motherboard to connect and communicate with each parts of the motherboard including central processing unit(CPU)
2 types of motherboard bus
.internal
.external
-External serves as the interface for peripheral devices like:
.hardisk
.CD-ROM drive
.flash drive to get connected to the cpu
The shape of each interface is unique to prevent plugging a device to a wrong port which could cause damage to the device while being connected to the cpu
RAM
-is the computer's short-term memory.(volatile storage) when the power is off,the data stored in RAM's cleared out
ROM
can only be read and not written to(non-volatile storage) although the power is off,the data stored in ROM will be kept.
HARDWARE1.Different kind of motherboard
-pc motherboard
Integrated motherboard
Non-integrated motherboard
designs of the motherboard
ATX
Micro ATX
BTX
NLX
2. what is the different between AX and ATX motherboard? Sketch the layout of the two motherboard.
3.pin number of varios kind of connector on the motherboard and at the back of the pc.
• parallel port-25
• VGA-15
• Game port-15
• Serial port-9
• Mouse connector-7
• Keyboard connector-7
• CD-ROM-39
• Floppy disk-33
• Soundcard-15
• Hard disk 1-39
• Hard disk 2-39
4.DC voltages we can find from the DC power supply
5.list down the electrical problem we are facing when operating our pc?
6.what are ESD, EMI, and RFI?
ESD-Electrostatic Discharge, or ESD, is a single-event, rapid transfer of electrostatic charge between two objects, usually resulting when two objects at different potentials come into direct contact with each other. ESD can also occur when a high electrostatic field develops between two objects in close proximity. ESD is one of the major causes of device failures in the semiconductor industry. EMI-EMI (electromagnetic interference) is the disruption of operation of an electronic device when it is in the vicinity of an electromagnetic field (EM field) in the radio frequency (RF) spectrum that is caused by another electronic device. RFI-Request made typically during the project planning phasewhere a buyer cannot clearly identify product requirements,specifications, and purchase options. RFIs clearly indicate that award of a contract will not automatically follow.
7.list different kind of pc storage.
• Flash drive
• External hard drives
• Smart card
• Online storage
• Re-writable CDs and DVDs
8.list various kinds of RAM and their pin numbers.
• 72 pins SIMM
• SDRAM-168 pin
• RDRAM-184 pin for 16 bit RIMM/232 pin for 32 bit RIMM
• DDR SDRAM-184 pins
• DDR-2 -240 pins
• 144-pin SODIMM
• 200-pin SODIMM
PRINTER AND NETWORK1. List down the types of printer and explain briefly.
• Dot-Matrix printer-A type of impact printer that produces characters and illustrations by striking pins against an ink ribbon to print closely spaced dots in the appropriate shape. Dot-matrix printers are relatively expensive and do not produce high-quality output.
• Ink Jet printer-A type of printer that works by spraying ionized ink at a sheet of paper. Magnetized plates in the ink's path direct the ink onto the paper in the desired shapes. Ink-jet printers are capable of producing high quality print approaching that produced by laser printers.
• Laser printer-A type of printer that utilizes a laser beam to produce an image on a drum. The light of the laser alters the electrical charge on the drum wherever it hits. The drum is then rolled through a reservoir of toner, which is picked up by the charged portions of the drum. Finally, the toner is transferred to the paper through a combination of heat and pressure.
2. What are stages we need to know when troubleshooting laser printer?
1. Cleaning – The Photosensitive drum is cleaned before it can take on a new image
2. Charging – To make the drum receptive to new images, it must be charged. The EP drum is given a negative charge by the primary corona wire around -600 and -1000 volts
3. Writing - A laser beam is use to write to the EP drum causing dots on the drum to lose some of the negative charge and become relatively positive charge
4. Developing - A toner is transferred from the toner cylinder to the EP drum by attracting the area of the drum that has a Relative positive charge
5. Transferring - The transfer corona wire puts a highly positive charge on the paper once the paper has a positive charge the negatively charge toner particle leaps from the drum into the paper
6. Fusing - The compression roller and fusing roller press and melts the toner into the paper the fuser gets very hot
3. Why we are still using DOT Matrix Printer?
Because it is cheap to maintain and supply. They can also make multi-part carbon-less forms which laser and ink-jet cannot.
4. What types of ports or interface used to connect our printer and PC?
• USB
• Parallel – IEEE 1284 Standard Cable
• Serial – RS232 Standard Printer Cable
6. What is computer network?
Networks are collections of computers, software, and hardware that are all connected to help their users work together. It connects computers by means of cabling systems, specialized software, and devices that manage data traffic. It also enables users to share files and resources, such as printers, as well as send messages electronically (e-mail) to each other.
2 types of computer network:
• A client/server network: uses one or more dedicated machines (the server) to share the files, printers, and applications.
• A peer-to-peer network: allows any user to share files with any other user and doesn’t require a central, dedicated server.
7. Why using computer network (advantages). Also explain the disadvantages.
Advantages of Computer Networks
•File Sharing: - allows file sharing and remote file access.
-A person sitting at one workstation of a network can easily see the files present on the other workstation, provided he is authorized to do so.
-It saves the time which is wasted in copying a file from one system to another, by using a storage device.
-In addition to that, many people can access or update the information stored in a database, making it up-to-date and accurate.
•Resource Sharing: Resource sharing is also an important benefit of a computer network. For example, if there are four people in a family, each having their own computer, they will require four modems (for the Internet connection) and four printers, if they want to use the resources at the same time.
- A computer network, on the other hand, provides a cheaper alternative by the provision of resource sharing. In this way, all the four computers can be interconnected, using a network, and just one modem and printer can efficiently provide the services to all four members. The facility of shared folders can also be availed by family members.
•Increased Storage Capacity: As there is more than one computer on a network which can easily share files, the issue of storage capacity gets resolved to a great extent. A standalone computer might fall short of storage memory, but when many computers are on a network, memory of different computers can be used in such case. One can also design a storage server on the network in order to have a huge storage capacity.
•Increased Cost Efficiency: There are many software available in the market which are costly and take time for installation. Computer networks resolve this issue as the software can be stored or installed on a system or a server and can be used by the different workstations.
Disadvantages of Computer Networks
•Security Issues: One of the major drawbacks of computer networks is the security issues involved. If a computer is a standalone, physical access becomes necessary for any kind of data theft. However, if a computer is on a network, a computer hacker can get unauthorized access by using different tools. In case of big organizations, various network security software are used to prevent the theft of any confidential and classified data.
•Rapid Spread of Computer Viruses: If any computer system in a network gets affected by computer virus, there is a possible threat of other systems getting affected too. Viruses get spread on a network easily because of the interconnectivity of workstations. Such spread can be dangerous if the computers have important database which can get corrupted by the virus.
•Expensive Set Up: The initial set up cost of a computer network can be high depending on the number of computers to be connected. Costly devices like routers, switches, hubs, etc., can add up to the bills of a person trying to install a computer network. He will also have to buy NICs (Network Interface Cards) for each of the workstations, in case they are not inbuilt.
•Dependency on the Main File Server: In case the main File Server of a computer network breaks down, the system becomes useless. In case of big networks, the File Server should be a powerful computer, which often makes it expensive.
8. Explain what is Peer to Peer and Server Based (client server) network.
Peer-to-peer network
In a peer-to-peer network (see Figure 3), a group of computers is connected together so that users can share resources and information. There is no central location for authenticating users, storing files, or accessing resources. This means that users must remember which computers in the workgroup have the shared resource or information that they want to access. It also means that users must log on to each computer to access the shared resources on that computer. In most peer-to-peer networks, it is difficult for users to track where information is located because data is generally stored on multiple computers. This makes it difficult to back up critical business information, and it often results in small businesses not completing backups. Often, there are multiple versions of the same file on different computers in the workgroup. In some peer-to-peer networks, the small business uses one computer that is running a client operating system, such as Microsoft Windows 98 or Windows XP Professional, as the designated "server" for the network. Although this helps with saving data in a central location, it does not provide a robust solution for many of the needs of a small business, such as collaborating on documents.
Server-based network In a server-based network, the server is the central location where users share and access network resources . This dedicated computer controls the level of access that users have to shared resources. Shared data is in one location, making it easy to back up critical business information. Each computer that connects to the network is called a client computer. In a server-based network, users have one user account and password to log on to the server and to access shared resources. Server operating systems are designed to handle the load when multiple client computers access server-based resources.
9. List down the operating system that use peer or server based network.
10. Explain briefly 5 different services used in computer network.
• PAN(Personal Area Netwwork)
• CAN(Campus Area Network)
• MAN(Metropolitan Area Network)
• WAN(Wide Area Netwwork)
• GAN(Global Area Network)
11.What do we needs if we want to setup small LAN.
In order to set up a network, ethernet hub, an ethernet adapter for each computer you want to add to the network, and cables.
12. List down the network topology. Explain the advantages and disadvantages.
Bus Topology
Advantages
It is easy to handle and implement.
It is best suited for small networks.
Disadvantages
The cable length is limited. This limits the number of stations that can be connected.
This network topology can perform well only for a limited number of nodes.
Ring Topology
Advantage
The data being transmitted between two nodes passes through all the intermediate nodes. A central server is not required for the management of this topology.
Disadvantages
The failure of a single node of the network can cause the entire network to fail.
The movement or changes made to network nodes affects the performance of the entire network.
Mesh Topology
Advantage
The arrangement of the network nodes is such that it is possible to transmit data from one node to many other nodes at the same time.
Disadvantage
The arrangement wherein every network node is connected to every other node of the network, many of the connections serve no major purpose. This leads to the redundancy of many of the network connections.
Star Topology
Advantages
Due to its centralized nature, the topology offers simplicity of operation.
It also achieves an isolation of each device in the network.
Disadvantage
The network operation depends on the functioning of the central hub. Hence, the failure of the central hub leads to the failure of the entire network.
13.List down the networking devices used to create LAN and WAN.
LAN
• Hubs
• Bridges
• Switches
• Routers
WAN
• Modem
• CSU/DSU(Channel Service Unit / Data Service Unit)
• Access server
• WAN switch
• Router
• Core Router
14.What media and connector used in BUS, STAR and RING topology?
Bus Topology
A single cable is used to connect all computers devices with interface connector. A single device send message towards other devices attached with it but only intentional recipient accept and process the message. The compulsory part of Bus topology is backbone because if it fails then there is no communication possible among computers. In-fact Bus topology has some advantages such as it is very easy and understandable. There is no much wires used for connectivity therefore it is less expensive. A user can easily extend a Bus topology because two cables can easily joined with a one long cable which is Barrel connector. Bus Topology have some drawbacks that its speed become slow with heavy traffic and then only one computer can send any message., The troubleshooting of Bus Topology also very difficult. If any cable is loose or breaks from any part then all activities are stopped and the rest of the devices or computers connected to the network stop responding.
Star Topology
A central device like hub, router and switch is used to connect all computers in a star topology. The functionality of connected devices is entirely different from each other in star topology because it may be Shielded Twisted Pair (STP) cable or unshielded pair cable (UTP) cabled. It is a most usable topology in local area network from all over the world. For star topology we need many devices and cables as compared to Bus topology. Star topology has some benefits such as it is easy to configure, and you can easily increase computers in a network without any disturbance. You can easily diagnose the error due to central device. In star network if any cable or node failure then there is no effect on entire network but if switch, hub or router failure then all network lay down. The drawbacks of Star topology is that it is an expensive because all computers connected with central device via cables .
Ring Topology
In Ring Topology all computers are situated in the form of a ring and each computer connected within two neighbor’s computer by the means of communication.
In Ring topology all computers communicate with each other clockwise or anti clockwise. Generally FDDI, Token ring and SONET used to configure ring topology.
The use of ring topology increasing day by day because a network can easily implement in home, office, building, and school .Ring topology have some benefits such as equal access to every one, transformation of data at very high speed but have disadvantages like The fault in any cable or wire may cause of failure network.,trouble shooting also a major problem.15.What do meants by attenuation? How to reduce these effects?
Attenuation is a loss of signal strength measured in decibels (dB).
It occurs for several reasons:
•range - both wireless and wired transmissions gradually dissipate in strength over longer reaches
•interference - on wireless networks, radio interference or physical obstructions like walls also dampen communication signals
•wire size - on wired networks, thinner wires suffer from higher (more) attenuation than thicker wires
16.List down the bandwidth for all the topology in LAN.
17.What is simplex, Half and Full Duplex.
•Simplex is a One-way communication.
•Half-Duplex is Two-way communication,one direction at a time.
•Full-Duplex is Two-way simultaneous communication.