Topology describes the structure of a network or how a network is designed. This pattern is very closely related to media access and delivery methods used. There were highly dependent topology with geofrapis location of each terminal, the quality control needed in the communication or messaging, as well as the speed of data transmission. In the definition of topology is divided into two, namely the physical topology (physical topology), which indicates the position of the physical cabling and topology of logic (logical topology) which shows how a medium accessible by the host. The physical topology is commonly used in building a network is: Point to Point (Point to Point). Networking ketitik point is the most simple networks but can be used widely. Once the simplicity of this network, which is often not considered as a network but only an ordinary communication. In this case, both nodes have the same level position, so that any node can initiate and control the relationship in the network. Data sent from one node another conclusion as the recipient directly, such as between terminals with the CPU. Star Network (Star Network). In a star configuration, some existing equipment will be linked into a central computer. Existing controls will be concentrated at one point, such as workload and set the settings of existing resources. All links should be related to the central data channel if you want to target other conclusion. In this case, when the center was down, then all terminals may also be disrupted. Star network model is relatively very simple, so widely used by the parties of the bank which usually have many branches in different locations. With the existence of this star configuration, then there are all sorts of activities at the branch offices it can be properly controlled and coordinated. In addition, the education world too much advantage of this star networks to control their students' activities. Excess · Damage on one channel only affect the channel network and the station adrift. · Security level is high. · Hold on a busy network traffic. · Additions and reductions station can be done easily. Shortage · If the node was malfunctioning, then the entire network to a halt. Handling · Prepared Need backup middle node. Ring Networks (Ring Network) In this network there are several devices are connected to one another and ultimately form the chart as well as a ring. Ring network does not have a point that acts as a central regulator or the data traffic, all nodes have the same level. Data sent will go throu Figure 3.1 star network topologygh several nodes, so arrive at the destination node. In the present data, the network can move in one or two directions. However, existing data remain moving in one direction at a time. First, existing messages will be delivered from other ketitik point in one direction. When encountered a failure, for example, there is damage to the existing equipment, so existing data will be sent with the second, then the message is transmitted in the opposite direction, and could ultimately end up at destination. Such a configuration is relatively more expensive when compared with the star network configuration. This is due, any existing node will act as a computer that will handle every application that it faces, and should be able to share resources on the existing network. In addition, this system is more suitable to use for systems that are not centralized (decentralized-system), which is not required to do a particular priority. Figure 8.2 Network topology ring Tree Network (Network Tree) In tree networks, there are several levels of nodes (node). Central or higher level node, another node can set a lower level. Data sent to the central node first. For example to move from a computer with a node-3 node kekomputer-7 as well as in the figure, the data must pass through node-3, 5 and node-6 before ending at the node-7. Keungguluan network tree model like this is, can the establishment of a group that is required at all times. For example, companies can form a group consisting of terminal accounts, as well as on other groups formed to terminal sales. The weakness is, if the node is higher then does not work, then the other group who are below it eventually also became ineffective. How the network is relatively slow tree Figure 8.3 Network topology tree Bus Network Another configuration is known as a bus-network, suitable for areas that are not too large. Each computer (each node) will be connected by a communication cable through an interface. Each computer can communicate directly with computers or other equipment contained within the network, in other words, all nodes have the same position. In this case, the network is not dependent on the existing computer center, so that when one device or one node is destroyed, the system can still operate. Each node has an existing address or nature itself. So that access to the data from one node, the user or the user simply mentioning the address of the node in question. Buses are the development of excellence network topology or adding new workstations can be done easily without disturbing other workstations. The weakness of this topology is that if there is interference along the center of the entire cable network would be disrupted. Figure 8.4 Network topology bus Plex Network (Network Combination) Network is a truly interactive, where every node has the ability to directly access not only to computers but also with other devices or nodes. In general, the network has a shape similar to a star network. Organization of existing data using the de-centralization, is to perform maintenance, use centralized facility. Figure 8.5 Network topology combinations Topology and logic are generally divided form the two types, namely: a. Broadcast Topology In simple terms can be described that is a host that sends data to all other hosts on the network media. b. Token Passing Topologies Set the data transmission to the host through the media by using the token that regularly rotates in a whole host. The host can only send data only if that host has a token. By this token, collision can be prevented. Factors - factors that need consideration for the selection of topology is as follows: · Course fee What is the most efficient system is needed within the organization. · Speed To what extent has the needed speed in the system. · Environment Such as electricity or factors - other environmental factors, influencing the type of hardware used. · Size Up to how big the size of the network. Does the network need a file server or a dedicated server. · Connectivity Does the other user who uses a laptop computer to access the network from various locations.

Windows Defrag Disk Defragmenter is one inherent feature of Windows that is used to analyze the volume of the drive and rearrange all the files and folders that exist on the drive that the defrag. The goal is that all files and folders are tidied his composition so that the system can be easier and faster when accessing files and folders. In other words, if you defrag the drive / volume so our computer will be faster. How to defrag windows pake: 1. Close all applications, so that maximum results defrag process. 2. Start menu -> Programs -> Accessories -> System Tools -> Disk Defragmenter 3. Then the drive volume will appear to list 4. Select the volume that would at Defrag 5. Analyze to analyze only 6. Defragment to analyze and then after finishing the analysis will proceed to defrag the volume of the selected process. But if going to defrag should confirm when the process goes not to stop by any factor (eg power failure, restart, etc.). Because if the defrag process is not finished yet suddenly stopped, it could be your hard drive is going bad sectors or broken.

1.Mikroprosesor Microprocessors are single chip that has a series of arithmetic, logic and control (Arithmetic Logic Unit / ALU and Control Unit / CU), from a general-purpose processing, control systems and counting systems. Thus the combination sometimes include a number of reminders (memory) in flakes (chips) are equal, ie central processing units (central processing unit) of the system, that called prosesor.serpih CPU can be obtained from various manufacturers in a variety of long words: 4,8,12,16,32 or 64bit. The technology in use adalalah * CCD, PMOS, NMOS, CMOS, Bipolar, IIL, DMOS, VMOS table 2. CENTRAL PROCESSING UNIT (CPU) CPU is the processing instructions program.pada microcomputer, the processor is called a microprocessor. CPU consists of two main sections, namely control unit (control unit) and the arithmetic and logic unit (arithmetic and logic unit). In addition there are also some deviation of the size kecilyang called registers. 2 3. CONTROL UNIT The task is a control unit: 1. regulate and control the means of input and output 2. Set instructions from main memory. 3. Mengmbil data from main memory if needed down the process. 4. Sending Instructions to ALU arithmetic calculations or if there is comparison logic, and supervises the work of the ALU. 5. Storing the results of the process into main memory. 4.ARITHMETIC AND LOGIC UNIT (ALU) * The main task of the ALU is to perform all arithmetic calculations or mathematics that occurs in accordance with the instructions of the program. * In addition, the decision of the ALU also perform logic operations in accordance with program instructions. 5. REGISTER Register is a small savings which have high speed, much faster about 5 to 10 times in comparison with the speed of return data from the recorder or play memory.Register in use to store instructions and data that are in the process olrh CPU, medium of instructions and other data who were waiting for the process is still in store in main memory. 6. Array PROCESSOR When a large number of calculations to be done, to speed up processing time, can be used in an array processor. An array processor or Coprocessor is a separate processor that can be added to the main processor. With an array processor, the computation of a large and difficult arithmatika can be done by breaking aiau dividing the computation and carried out jointly between central processor and array processor. Because the main function of the co-processor or processor array is a complex mathematical calculation, it is also called math-processor or numeric data processor. 7. Microprocessors and microcomputers TURNING INTO To build all the necessary tasks a computer, the CPU must be equipped with reminders (memory) additional hour (clock), the mobile intermediate adapter (PIA) for the instrument input and output (I / O). 4 The number of flakes Chip) complementary around the microprocessor in the picture above ranged from 10 to 80 pieces, and mounted on a printed circuit board (printed circuit board / PCB). The number of transistors on board equivalent to more than 100,000, even up to tens of millions of 5 8. MAIN MEMORY CPU only can store data and instructions in a register of its small size, so can not store all the information needed for the entire process from the program. To overcome this, then the processing device is equipped with a capacity greater savings, that is played is also called primary storage or storage. Main memory consists of RAM and ROM a. ROM ROM: read only, not to fill something into the ROM. The contents of ROM is already filled by the manufacturer, a system OPERATING! (Operating System) which consists of basic courses required by the computer system, such as a program to regulate the appearance of characters on the screen, filling the key button on the keyboard fatherly certain control purposes and the bootstrap program. Bootstrap program is needed in the first time a computer system is activated - boot (cold boot / warm boot) instructions stored in ROM or microinstructions called microcode. Also referred to as firmware, as hardware and software put together by the manufacturer. b. RAM RAM: all data and programs that are inserted through the instrument input, are stored in main memory used knususnya in RAM (Random Access Memory). RAM is memory that can be accessed (optional / retrieved its contents) by the programmer. RAM structure is divided into four parts: 1. Added storage - accommodates input is entered via input devices. 2. -Storage program stores all the program instructions to be processed. 3. Working storage-storing data to be processed and the results of processing 4. Accommodate the output storage-final results from the processing of data to be displayed to the output device. Input is entered through the input device, was first housed in the input storage beforehand, when the input shaped the program, then transferred to the program and if the form of data storage, will be transferred to working storage. Results of processing are also accommodated in the working storage and the results will be displayed to the output device was transferred to the output storage. 9. CACHE MEMORY Multiple CPU using a cache memory or buffer memory with the intention of the CPU to work more efficiently and reduce the time wasted. Without cache memory, the CPU will wait until the data or instructions received from main menrory or waiting for the results of the processing is completed is sent to main memory, the new process can then be performed. Padanal process of main memory is slower than the speed of the register. Cache memory is placed in between the CPU and main memory. Cache memory should be faster than main memory and has a large enough size, but not as much main memory. Actually the cache memory is not necessary when main memory as fast as cache memory, but the way it is not economical.

How to Be Safe on Social Networking Sites.

Would you tell a complete stranger all about your family, work, love life, hobbies and interests? And give them some personal photos to look at too? Most people approached on the street would probably answer ‘no’ to the above questions. But on the Internet, that’s exactly what millions of us are doing on the hugely popular social networking sites and chat rooms. Online social networks are fun and hip, but they also present a major security concern for Internet users.

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• Social networking sites are also used by predators and pedophiles searching for possible victims. It’s easy for anyone to adopt false identities on the Web, so you should maintain a healthy skepticism over what you see and hear on social networking sites. The bright young student you are conversing with could always be a middle-aged fraud. If you want to meet a person who you have befriended online, always do it in a public place, preferably accompanied by someone.
• Many online social networks encourage users to import content like video clips and also accept third party add-on applications. This can be exploited by virus writers as a way of getting malicious code into the networks, such as the worm which spread rapidly on Orkut’s web site last year, infecting an estimated 655,000 users in Brazil.