Thursday, 12 December 2013

TORRENTS

We all like torrents a lot. But you ever try to understand the term TORRENTS in a broader sense. In this post I will share some terms related to torrents.
BASIC TERMS:-

1.) TORRENTS- Also called as BitTorrent is a protocol supporting practices of peer-to-peer file sharing that is used to distribute large amount of data or files through internet.

2.) DOWNLOADER- A downloader is any peer that does not have the entire file and is downloading the file. 

3.) LEECH- Leech has two meanings. Often, leecher is synonymous with downloader (see above): simply describing a peer or any client that does not have 100% of the data.The term leech also refers to a peer (or peers) that has a negative effect on the swarm by having a very poor share ratio, downloading much more than they upload. Leeches may be on asymmetric Internet connections or do not leave their BitTorrent client open to seed the file after their download has completed. However, some leeches intentionally avoid uploading by using modified clients or excessively limiting their upload speed.

4.) PEER- A peer is one instance of a BitTorrent client running on a computer on the Internet to which other clients connect and transfer data. Depending on context, "peer" can refer either to any client in the swarm or more specifically to a downloader, a client that has only parts of the file.

5.) SWARM- Together, all peers (including seeds) sharing a torrent are called a swarm. For example, six ordinary peers and two seeds make a swarm of eight.

6.) P2P- Stands for "peer to peer", which is the technology used for file sharing among computer users over the Internet. In a p2p network, each node (or computer on the network) acts as both a client and a server. In other words, each computer is capable of both responding to requests for data and requesting data itself.

7.) HASH- The hash is a string of alphanumeric characters (typically hexadecimal) in the .torrent file that the client uses to verify the data that is being transferred. Hash is the shorter form of the word Hashsum.
Torrent files contain information like the file list, sizes, pieces, etc. Every piece received is first checked against the hash. If it fails verification, the data is discarded and requested again. The Hash Fails field in the torrent's General tab shows the number of these hash fails. Hash checks greatly reduce the chance that invalid data is incorrectly identified as valid by the BitTorrent client, but it is still possible for invalid data to have the same hash value as the valid data and be treated as such. This is known as a hash collision. Torrent and p2p files typically use 160 bit hashes that are reasonably free from hash collision problems, so the probability of bad data being received and passed on is very small.

 HOW IT WORKS??
Instead of downloading a file from a single source server, the BitTorrent protocol allows users to join a a "swarm" of hosts to download and upload from each other simultaneously. A user who wants to upload a file first creates a small torrent descriptor file that they distribute by conventional means (web, email, etc.). They then make the file itself available through a BitTorrent node acting as a seed. Those with the torrent descriptor file can give it to their own BitTorrent nodes which, acting as peers or leechers, download it by connecting to the seed and/or other peer. 

SOME TORRENT CLIENT SOFTWARES:-
1.) TIXATI 
2.) VUZE
3.) uTORRENT
4.) TURBOBT
5.) DELUGE
6.) BITCOMET
7.) TRANSMISSIONBT
(Click on above names to download)

SOME TORRENT  PROVIDING SITES:-
1.) http://thepiratebay.sx/
2.) unblockfenopy.eu/‎
3.) www.bitsnoop.com
4.) www.torlock.com
5.) www.seedpeer.com
6.) www.bitenova.org/‎
7.) www.torrentfunk.com/


Friday, 22 November 2013

*PC ERRORS*



Here some common PC errors and the solutions for them... Do have a look...................!!
1. MONITOR LED IS BLINKING
Check all the connections like Monitor Cable, Data cables ,RAM, Display Card , CPU connections.
2. CONTINUOS THREE BEEPS
Problem in RAM Connection.
3. THREE BEEPS ( 1 Long 2 Short)
Problem in Display Card Connection
4. THREE LONG BEEPS PERIOD WISE
Problem in BIOS or RAM (Basic Input Output System)
5. CONTINUOS NON-STOP BEEPING
Key Board Problem (I.e.; Some Key is pressed for
Longer time)
6. FDD LED IS GLOWING CONTINUOSLY
Data cable to be connected properly (twisted cable).
7. NO DISPLAY ON THE SCREEN AT ALL
Hard Disk cable connected wrongly. Connect rightly seeing the Red mark (Faces power supply) and then
Restart.
8. POWER LED IS OFF
a. Check main power cord
b. Check S.M.P.S.
c. Check Mother Board connection
9. SHOWING CMOS ERROR
Replace 3 Volt battery of Mother Board . Set Original settings Manually.(Refer CMOS Setup chart)
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10. SHOWING FDD ERROR OR FLOPPY DRIVE IS NOT WORKING PROPERLY
Check Power cord of FDD , Data Cables , set CMOS & Finally the Check drive.
11. SHOWING HDD ERROR OR HARD DISK FAILURE
a. Check Power Cord
b. Check connection of HDD
c. Check Data cable
d. Check Hard Disk parameters in CMOS or Auto
detecting Setting Partitions by Fdisk Command, then format it to set track 0.
12. MOTHER BOARD HANGS DUE TO UNSTABILIZED POWER SUPPLY
a. Check S.M.P.S
b. RAM not functioning properly.
c. Software problem (due to using pirated software)
d. CPU fan not functioning properly.
13. DANCING SCREEN
a. Check Display card connection
b. Virus Problem
c. Video Memory Problem
14. SHAKING SCREEN
a. Earthing problem
b. Magnetic waves comes around.
15. CPU CABINET SHOCK
a. Check Earthing
b. Check main power cord.
16. NON-SYSTEM DISK ERROR
a. Floppy Drive having different disk (Non-Bootable Disk) OR CMOS Parameters for Hard Disk may not be
set properly.
b. Hard Disk Partitions may not be created.
c. Hard Disk may not be formatted.
17. MISSING OPERATING SYSTEM
The System files missing namely ; command.com} -User File IO.SYS & MS_DOS.SYS } - Hidden Files. These
above three files required for Start up of the system
that can be transferred by using SYS C: Command OR
While the time of formatting by using Format c:/u/s
18. MISSING COMMAND INTERPRETOR
May the file Command.com is corrupted OR Infected by Virus OR Some one has Erased it.
19. SHOWING I/O ERROR
a. The type of Hard Disk in CMOS may not be set
properly.
b. Operating system used for formatting is not valid
20. SHOWING DIVIDE OVER- FLOW MESSAGE
a. May some Directories or Files crash with other files.
b. Use CHKDSK/F or SCANDISK Command to correct it.
21. HARD DISK MAKING NOISE WHILE PROCESSING
a. Unstabilized power supply.
b. Check for Loose Contact.
c. Do not use Y Connectors for Hard Disk.
d. It may create Bad Sector OR Weak Hard Disk.
22. HARD DISK HANGS WHILE PROCESSING
Check for Bad Sector by using CHKDSK or SCANDISK Command. If found format the Hard Disk and set
Partition before that area.(This is the only procedure to use Hard Disk with Bad Sector) OR (To avoid Bad
Sectors use Standard Power Supply)
23. HARD DISK NOT DETECTED
a. Check Power Connector
b. Check Data Cables
c. Check Jumpers
24. PARTITION NOT SHOWN
Operating System where the Hard Disk formatted is not supported with present Mother Board. For Eg:
Hard Disk formatted with Pentium System will hide
their partitions for 486 System.
25. MMX/DLL FILE MISSING
May the above files may be corrupted due to power failure or Virus. Make available above files from other Computer OR Reinstall Windows 98 Operating
System. (This procedure will not make any effect on
existing Data).
26. WINDOWS REGISTRY ERROR
This will happen due to sudden ON/OFF of the system. Final solution is to Reinstall Operating System.
27. DISPLAY COLOUR DOES NOT MATCH
a. Configure Display Card properly with their CD.
b. The Standard setting for Windows is set it to
800x600 for better performance.
28. UNKNOWN DEVICE FOUND
May the Driver utility is not provided with operating system. Insert Driver CD and install software for the
above Device...

MAKE CREATIVE PROJECTS WITH SCRATCH

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Tuesday, 6 August 2013

ACCESS METHODS


An access method is a set of rules governing the network nodes that share the transmission medium. There are three methods of of media access methods:
1.     CONTENATION- It means that the PCs are contending (competing) for the use of transmission medium. Any PC can transmit data at any time on first come first serve basis. But the system breaks down when 2 PC try to transmit data at the same time. This usually happens when the network is too busy & tries to transmit data which results in collisions of data packets. Mechanisms like Carrier Sensing Multiple Access (CSMA) are usually used to minimize the collisions. Each computer “listens” to the network before attempting to transmit data. If the network is busy then the computer avoids transmitting data until the network settles down. Another mechanism is Carrier Detection (CD) in which computers continue to “listen” to network as they transmit data. If the computer detects another signal that is interfering with the signal it is sending then it stops transmitting. Both computers then wait for random interval time & try to retransmit.  
2.   POLLING- One device is responsible for polling the other devices to see whether they are ready for transmission or reception of data. Polling-based systems use a device called master device or controller. This access method is not widely used on networks because polling itself can cause some network traffic.
3.  TOKEN PASSING- The computer takes turns to use the transmission medium. This system utilizes a frame called token, which circulates around the network. A computer that needs to transmit waits until it receives a token, at which time the computer is permitted to transmit. The computer then passes the token frame to the next station on the network. 
NETWORK TOPOLOGY
Topology is the map of network. The 2 basic categories are as follows:
        1.  PHYSICAL TOPOLOGY- It describes actual layout of the network.
        2.  LOGICAL TOPOLOGY- it describes the logical pathway followed by a signal as it passes through the network nodes.
The 4 basic types of network topology is as follows:

      1.    BUS- The bus topology is ideally suited for networks that use contention-based access methods. All PCs are connected to the same central cable called bus or backbone. The cable is terminated at each end. A special connector called terminator is placed at the end to prevent signals from reflecting back on the cable and causing interference. Wiring is normally done point to point. A faulty cable or workstation will take the entire LAN down.
      2.  RING- All PCs are connected to one another in shape of ring, so that each device is connected directly to two other devices, one on either side of it. Each device has a receiver and a transmitter and acts as a repeater that passes the signal to the next device in ring. As the signal is regenerated at each device, the signal degeneration is low. Faulty workstations can be bypassed. More cabling required than bus topology.
    3STAR- All PCs are connected to a central part, a server or hub. The hub receives signals from other network devices & routes them to destinations. Star hubs can be interconnected to form a tree or hierarchical topology. It has the greatest cable lengths of any topology.
     4.  MESH- A mesh topology is really a hybrid model representing an all-channel sort of physical topology. Every device is directly connected to every other device in network. Any new device must be connected to all existing device. If there is any break in the transmission medium, the data transfer takes alternative routes. Cabling is more extensive and complicated. 

Sunday, 28 July 2013

TYPES OF NETWOKS


                                 NETWORKING FUNDAMENTALS
  NETWORKING- The computer networking refers to 2 or more PCs linked to each other. The link can either be wired or wireless.

    TYPES OF NETWORK- There are 4 types of networks
    1.LAN- Local Area Network generally called LAN’s. LAN are privately owned network within a single building or campus of up to a few kilometres in size. They are kindly use to connect personnel computers and work stations in company office and factories to share resources.
Ex: - Share printer and Exchange information.

    2.CAN- Campus Area Network (CAN) connects 2 or more LANs but it is limited to specific area such as campus of a company or college, an industrial complex, etc.  

  3.MAN- Metropolitan Area Network generally called MAN’s. MAN is basically a bigger version of LAN and normally uses similar technology.
          It might cover a group of nearby corporate officers or as cities and might private or public. A MAN can support both data and voice might even be related to local cable television network. The main reason for even distributing MAN as a special category is that a standard adopted for them and this standard is now being implemented. It is called DQDB (Distributed Queue Dual Bus) consist of two unidirectional buses to which all computers are connected as show main people each bus has a head end  device that initiates transmission activity traffic that is designed for a computer to the right of the center uses the upper bus.
                              

       4.WAN- Wide Area Network generally called WAN’s. WAN span a large graphical area network of own a country or continent.
It contain a collect of machine intended for running uses program we will follow traditional uses and called his machine host. Then term and system in same time also use the wireless transmissions. The host are connected by the communications subnet. The job of subnet is carry to message from host as the telephone carries would from speakers and listeners.

5.GAN- Global Area Network generally called GAN’s. When any person have to connect internet GAN have give one coupon to the user and then connects internet by router. GAN have been used in mainly for satellite networks. It has no limitation for connectivity.