MAN ( Metropolitan Area Network )

Definition of MAN ( Metropolitan Area Network ) is a computer network that is large and spacious which is usually used in areas such as schools , colleges , malls and even the city as well . Actually there are two types of connections are typically used the first is by using a wireless connection and the second using fiber optic cable . For instance ,
a school or college has a MAN connection consisting of multiple LANs and are at a radius of a few pounds around the place . Then connect the campus with the MAN also has relationships with other universities to form a WAN or the Internet .
There are also other examples with some technology that uses MAN connections such as ATM , FDDI and SMDS . Here below I give also an explanation of the ATM , FDDI and SMDS .

1 . ATM , or Asynchronous Transfer Mode instead Automated Teller yes . ATM is a cell relay network protocol that clicking - encoded traffic or traffic data to a smaller cell forms such as 53 bytes , 48 bytes and 5 bytes .

2 . FDDI or Fiber Distributed Data Interface is a standard data transmission in a LAN that includes a sizable range is up to 200 kilometers away . FDDI can also include thousands of users . Standard medium is used to connect fiber optic , even though it could also use copper wires , but with the proviso shall be in accordance with the FDDI technology if not then the transmission will be interrupted .

3 . Or SMDS Switched Multi -megabit Data Services is a service connection to the LAN , MAN and WAN to the data exchange standard based on the IEEE 802.6 DQDB . For the connection between MAN and LAN can be done by using radio signals , microwaves and infrared .

Repair Hardisk BadSector

                                  

How hard drive can be exposed BadSector ? Here's one of the causes of the affected hard drive BadSector Bad data cable or have been unsuitable .

Power Supply is not good or the load of the power supply is not in accordance with the load of the PC .

Electric voltage is not stable or up and down . Suggested use Stabilizer / Stavol .

Hard drive never fell .

I will help provide solutions for you that may be new experience BadSector on your hard drive .

Keep the data cable is always good 6 or 12 months change .

Power Supply power cable for the hard drive try no connection with the other cables . Better yet use the Pure Power Supply 500W , but if you use a 1TB hard drive ( Terrabytes ) I recommend using the Pure Power Supply 1000W power that flowed more stable .

If you like loose plug the hard drive would be nice if the hard drive is inserted into traveling bag or small bag to avoid accidents fell hard drive .

If all the above tips have you tried and it turns out you hit BadSector hardsisk eg 4KB please try using HDD Regenerator or Flobo HDD Repair . Please try the one that you think is good which, the 2 software is software which I use to repair your hard drive or hard drive BadSector suddenly lost its partition . If you do not know how to partition your hard drive can read the article using fdisk to partition and if you are confused to select the system partition on the hard drive please read also about NTFS Vs FAT .

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How PC Power Supply Works

Power Supply is a very important part in the computer , without the computer power supply you will never live . Power Supply is one of the least understood components in the PC and at the same time the power supply is one of the most important parts . When the power supply has been bad or improper use , your computer will also be problematic . Well , I will explain to you how important the power supply to the computer .


As I mentioned earlier the power supply is a very important part in the computer . If you are planning to do a major upgrade on your computer , it's good power supply will also be replaced because it will affect the performance of the computer .

Then how do you know you are bad power supply ? Well , here I will explain the problem to you . There are a few things you should know such as overheating , failure or error on boot , appears sound , and even electric shock when you touch a PC .

If the power supply shows signs such as these examples , it may be time power supply needs to be replaced . Never try to repair it yourself if you have no experience . It's safer if you want to fix it take it to a technician or an expert . Or if you do not want to bother just buy a new one just practical , right?

Power supplies are rated by the output of watts . Computers are older models usually have or take a power of about 70 watts . In contrast to today's computers , the average computer is currently using and consuming about 230 watts or 250 watts or even more . If you buy a new power supply , buy the one with the meticulous and it would be nice also if you know the brand of the power supply is good .

The basics of how a power supply works .
Power Supply to change the default power is 120 volts of electricity into a form that can be used by your computer . Typically , motherboards , adapter cards , and disk drives require at least a 5 volt power , cooling fan or cooling requires 12 volts .
The power supply also affects computers especially at boot time . Since the power supply is sending power to the motherboard and make sure that the system has enough power to operate properly .
Major fan of your power supply is also very important because the power supply had to keep the temperature of the computer . And you always check the cooling fan power supply because it draws air through the vents and out of the hole in the back of the power supply . Therefore , before the PC is turned on make sure the power supply is good airflow and no dust attached .

AT vs. ATX
AT power supplies arguably the most common , simple and does not take a great power . While ATX require special power . ATX contains special circuitry that allows for at least 5 volt power supply to the motherboard even when the computer is off .
The fan on the power supply has ATX usually air flow is reversed . So that blows air into the PC released through the fan on the power supply .

Connector .
When the power supply is working , there is nothing you need to know about some of the connectors . The most important thing if you are using a new PC , you may need to connect the power cord to the power switch on the PC . Some people have trouble doing this , because there are four wires , and four tabs . In general, you will find four wires color .

The cables are color coded as follows :

Brown and blue cables are wired with 110V power .
They bring 110V power to the switch . They will always be hot when the power is attached .
Black and white wires carrying AC current entry into the power supply .
These wires will be hot when the system is active or PC you live , because in fact switch closes the circuit .
If you have a green wire , there is sometimes a line, it is a ground wire .
When connecting , place the blue and brown wires on the tab parallel and side by side .
Then place the black and white wires to the tabs that are angled and in addition to the blue wire .

I noticed a lot of people can put these wires without a problem , but you should ALWAYS make sure the position of the black and brown wires are right next to the blue cable .
Connectors are all pretty much the same , except for different size alone . There are some people sometimes ask about the pin , he is .

1 Yellow 12 V
2 Black Ground
3 Black Ground
4 Red +5 V

What can you do to make your power supply is more durable ?
Home computers are usually environmentally friendly . This means that the fan inside the PC works well in order to keep your computer cool and stay cool and also free of dust .

Try to minimize the amount of dust and pollution in the air around your computer , because the fan draws air into the PC . You also may have noticed holes in the power supply fan is covered with dust , make sure you always clean it because it will affect the performance of the power supply .

Use stavolt or better stabilizer or UPS so that power surge that enters your computer through a cable is not great . For UPS I suggest you use UPS already has a stabilizer so that if the power supply voltage being unstable alias up and down you do not worry your computer will be problematic or damaged .

Dual Channel Memory

Facts of Dual Channel Memory Terminology actually nothing , because things such as dual - channel DDR memory , especially on when it is properly used , hence the term " dual channel " refers to a chipset on the motherboard is designed with two memory channels instead of one . Dual Channel memory handling process more efficient by utilizing the theoretical bandwidth of two modules , thus reducing latency in the system and timing delays that often occur in a single memory module . For example , when the controller reads and writes data while the second controller prepares for the next access , without having to start reading / writing process from the beginning again .

Consider an analogy in which data is loaded into memory , then the data is sent to the CPU .
Single - channel memory will send the data to the processor through a single channel at a maximum rate of 64 bits at a time . On the other hand , dual - channel memory which uses two channels , has the ability to transmit data up to two times faster at a rate of 128 bits at a time . This process works the same way when data is " emptied " of the processor by turning the process flow of data . A chip " memory controller " is responsible for handling the data transfers involving all the memory modules and the processor . This chip controls the flow of data and prevent data flow is not excessive when the process is underway .

It is estimated that the dual- channel memory architecture is able to increase the bandwidth by 10 % .
Most systems that support dual -channel memory can be configured manually either single -channel or dual - channel memory . The fact that the motherboard supports dual - channel DDR memory , does not guarantee that the DIMM can be used in dual channel mode . Not enough to live only a few pairs of the memory module into the memory slot to enable dual - channel , users must follow specific rules when adding memory modules to ensure that they get the performance of a dual - channel memory . Intel specifies that the motherboard has dual channel function must be in the default mode or single-channel mode because if these rules are violated, the function of dual channel motherboard will not run .

The following are the rules for dual channel run smoothly :
DIMMs ( memory ) must be installed in pairs .
Both DIMMs must use the same memory chip .
Both DIMMs must use the same DRAM bus width .
Both DIMMs must be either . ( Not Damaged or Dead RAM )

Virtual Memory Information

There are two types of memory, which are as follows:

* System Memory is a memory that is used to store the application data and instruction in order for the system to process and execute that application data and instruction. When you install the memory sticks to increase the system RAM, you are adding more system memory. System Memory can be known as either the physical memory or the main memory.

* Virtual Memory is a memory that uses a portion of HDD space as the memory to store the application data and instruction that the system deemed it doesn't need to process for now. Virtual Memory can be known as the logical memory, and it controls by the Operating System, which is Microsoft Windows. Adding the Virtual Memory can be done in system configuration.


Tutorial Information & Facts or Implementation

Virtual Memory is a HDD space that uses some portion of it as the memory. It is used to store application data and instruction that is currently not needed to be process by the system.

During the program loading process, the system will copy the application data and its instruction from the HDD into the main memory (system memory). Therefore the system can use its resources such as CPU to process and execute it. Once the system memory gets filled up, the system will start moving some of the data and instruction that don't need to process anymore into the Virtual Memory until those data and instruction need to process again. So the system can call the next application data and instruction and copy it into the main memory in order for the system to process the rest and load the program. When the data and instruction that is in the Virtual Memory needs to process again, the system will first check the main memory for its space. If there is space, it will simply swap those into the main memory. If there are not any space left for the main memory, the system will first check the main memory and move any data and instructions that doesn't need to be process into the Virtual Memory. And then swap the data and instruction that need to be process by the system from the Virtual Memory into the main memory.

Having too low of Virtual Memory size or large Virtual Memory size (meaning the size that is above double of the system memory) is not a good idea. If you set the Virtual Memory too low, then the OS will keep issuing an error message that states either Not enough memory or Virtual too low. This is because some portion of the system memory are used to store the OS Kernel, and it requires to be remain in the main memory all the time. Therefore the system needs to have a space to store the not currently needed process data and instruction when the main memory get filled up. If you set the Virtual Memory size too large to support the intensive application, it is also not a good idea. Because it will create the performance lagging, and even it will take the HDD free space. The system needs to transfer the application data and instruction back and forth between the Virtual Memory and the System Memory. Therefore, that is not a good idea. The ideal size for the Virtual Memory is the default size of Virtual Memory, and it should not be exceed the value of the triple size of system memory.

To determine how much virtual memory you need, since the user's system contains the different amount of RAM, it is based on the system. By default, the OS will set the appropriate size for Virtual Memory. The default and appropriate size of Virtual Memory is:

<Amount_Of_System_Memory> * 1.5 = <Default_Appropriate_Size_Of_Virtual Memory>
.

For example, if your system contains 256 MB of RAM, you should set 384 MB for Virtual Memory.

256 MB of RAM (Main Memory) * 1.5 = 384 MB for Virtual Memory


If you would like to determine how much the Virtual Memory is for your system and/or would like to configure and add more virtual memory, follow the procedure that is shown below. The following procedure is based on windows XP Professional.

1-1) Go to right-click My Computer and choose Properties

1-2) In the System Properties dialog box, go to Advanced tab

1-3) Click Settings button that is from the Performance frame

1-4) Once the Performance Options shows up on the screen, go to Advanced tab

1-5) Under the Advanced tab, click the Change button from the Virtual Memory frame to access to the Virtual Memory setting

Then the Virtual Memory dialog box appears on the screen. In there, you are able to check how much the Virtual Memory you set. If you would like to modify the size of Virtual Memory, follow the procedure that is shown below.

2-1) In there, select the drive letter that is used to install the Operating System

2-2) Choose the option that says, "Custom Size:"

Once you choose that option, the setting for Initial Size and Maximum Size become available for you to set. Initial Size (MB) means the actual size of Virtual Memory, and Maximum Size (MB) means the maximum size of Virtual Memory that is allowed to use.

Let's say if your system contains 512 MB of RAM, then the ideal setting for the Virtual Memory is as follows:


Initial Size (MB):  768
Maximum Size (MB):  1500


Once you are happy with that Virtual Memory size, click the Set button from Paging file size for selected drive to apply the setting for the Virtual Memory size. Then click the OK button to apply the setting.

That's where you can manage and configure for the size of Virtual Memory.


Additional Information

* To maintain the good overall system performance, you should be using the default size of actual size for Virtual Memory and the triple the value of the size of the main memory for the maximum size of Virtual Memory. If you find that main memory plus virtual memory is not big enough to load the intensive application, then you will need to add more main memory onto your system.