USB Cable Types

Developed by Intel, the Universal Serial Bus (USB) is a specification for enabling communication between various electronic devices and a host controller. The primary concept behind inventing USB was to replace all various serial ports with a standard connecting port. Through USB, various external devices can be connected to a computer like keyboards, mouse, flash drives, printers and other digital media devices. Since its inception, USB has become extremely popular and a standard connection technique used by most pTeople. Other than connecting external devices to computers, USB is also used as a power chord between an adapter and a device. The USB has a standard design which is followed across all major electronics and computer industries.

USB cables consist of only plugs while devices have receptacles to insert the plugs. The cables have a maximum length of 5 meters as data transferring is not possible with longer cables. Host systems have type-a receptacles and if at all devices have receptacles, then are of type-b. Normally, a USB cable has a USB type-a plug on one end, and a USB type-b plug on the other. However, there are different USB cable types differing on the plugs and receptacles, as described further. Read more on USB connector - USB cable.

Types of USB Cable

When the first USB cable was first created, it had only the standard type-a and type-b plugs as well as receptacles. After the USB 2.0 was invented, it came with additional mini type-b plugs and receptacles. Type-a connectors are flat and rectangular in shape, and plug into downstream ports on the host system. These types are mostly found on devices which have a USB connector permanently fixed on them. Type-b connectors are square and beveled at corners and are plugged into upstream sockets. These connectors are used when devices need to be plugged in at one end of the cable. Smaller devices like PDAs or digital cameras come with mini type-a or mini type-b connectors. Recently, a micro-USB connector was launched and used in latest mobile phones and PDAs. A more detailed information on various USB cable types in given below.

USB Cable Type a to Type a
This cable is used to connect two host devices or hubs with each other. Both USB devices need to have the type-a connector. The cable is a passive one and can be useful for connecting scanners, printers or hubs with the host system, generally a computer. However, this cable is not useful for connecting two computers via USB.

USB Cable Type a to Type b
This is the most common of all USB cable types and connects any standard peripheral device to a host system. The flattened connector is the type-a connector which is plugged into downstream sockets on the host system. The type-b connector is square in shape and its corners are beveled. It is plugged into upstream sockets on devices.

USB Cable Type a to Mini b
This cable is used to connect smaller devices like mobile phones and digital cameras to a computer. The type-a connector is flat and rectangular in shape and is connected into downstream ports on the host system. The mini-b connector is small, a little bit square and is plugged into upstream sockets present on certain devices like digital cameras and cell phones. It should be noted that not all small devices can be connected using this USB cable type, and is therefore essential to go through user manuals of digital and video cameras to know their compatibility.

USB Type a to Mini b (4 pin)
This is the latest addition to the USB and is exclusively used to connect Sony devices to a host system. It has a flat-headed, rectangular shaped type-a connector at one end and a mini type-b connector which is small and a little square in shape at the other end. Sony video cameras and digital cameras use this cable along with very few other leading brands. Check the manual before purchasing this cable.

USB Cable Type b to Type b
This cable has type b connectors on both of its ends. One end has a bracket assembly which can be screwed on to a wall plate, while the end end has the usual type-b connector. This type of USB cable is used mostly by AV installers, since it helps in connecting a laptop to a separate wall plate instead of connecting it directly to a white-board.

Of late, wireless USB has become popular among users as it provides more power efficiency. However, USB cables are still very much in use as people trust a wire to provide assured connectivity. Knowing the various USB cable types will surely help while purchasing a new one.
By Suketu Mehta

Taking a Screenshot

Want to save contents on your screen as it is for future use? Read the article and learn about taking a screenshot in Windows as well as Mac operating systems.

Screenshot is screen capture wherein you can create and save an exact image of the way the screen is appearing to you. A lot of people often wonder how do you print screen or take a screenshot, as there are numerous applications of this knowledge. Certain websites these days have restrictions on selecting and copying content or saving pictures from the web page to your computer. You can play smart by taking a screenshot and then cropping out the undesired part. Gamers, who have the urge to showcase their skills through a high score they have achieved or reached a particularly difficult level, can easily do so by taking a screenshot. In case you are having some trouble with your computer, you can grab a screenshot and email it to a person to show him the exact problem and ask for its solution. It is therefore handy learning how to take a screenshot, which can be done following simple instructions given below.

Taking a Screenshot on Windows

Taking a screenshot on a PC is much easier if you are using Windows Vista, as it has a specifically designed application for the same. But for people using Windows XP or any lower version, need to use the traditional 'print-screen' method. Details on the same are discussed below.

Taking a Screenshot in Windows XP

• Go to the page of which you want a screenshot of, and press the 'Prt Scrn' button on your keyboard. This button is next in line after the function keys.
• Click Start → All Programs → Accessories → Paint. This will open the Microsoft Paint window.
• When the paint window opens, click on the 'Edit' option on the menu bar, and select 'paste', or hold the 'ctrl' and V keys together. The screenshot will be pasted in the paint window and you can crop, resize and adjust the image as per your need.
• Next, go to the 'File' option on the menu bar and click on the 'save as' option. A widow will pop up after this in which you need to change the 'Save as Type' option to JPG, JPEG or PNG , as per your requirement. Type an appropriate name for your file in the 'File Name' space provided in the window and from the options appearing in the left hand corner of the window, select the location where you wish to save you file.
• Your screenshot is captured and successfully saved on your computer.

Taking a Screenshot on Vista

• There is a specifically designed toll for taking a screenshot, called the snipping tool, present in all versions of Windows Vista except the home basic version.
• Arrive on the page of which you want to take a screenshot. To take capture the screenshot, you will first have to open the snipping tool. Click on the start button menu type 'snip' in the search tab which appears on the left hand bottom region of the menu. Click on the snipping tool icon which will appear in the menu.
• As the snipping tool window opens, your screen will get covered in a white color mask. Click on the 'new' option present on the menu bar and you will see four options appearing in the drop-down list - full screen snip, window snip, free-form snip and rectangular snip.
• Select the option which best suits your requirement. The free-form snip mode lets you to manually draw and select the area of which you want the screenshot of, the full-screen mode selects the entire screen, while the window snip mode tool can select a particular window for your snapshot.
• After selecting the option and snipping your image, it will automatically get copied within the snipping tool and also to the windows clipboard, for your further use.

How to Take a Screenshot on a Mac

For people using a Mac operating system, can learn how to take a screenshot on a Mac following instructions given below.

• Command+Shift+3
  This command will automatically capture and save a screenshot of the entire screen as you see it, on your desktop in a PNG format.
• Command+Ctrl+Shift+3
  This command does the same function as the previous one, except that the screenshot you take will go to your clipboard and you can use it immediately.
• Command+Shift+4
  This command helps you to capture only a certain portion of your screen. When you press these keys together, a cross -hair cursor will appear on the screen which you can use to select the required screenshot area. After you release the mouse button, a PNG file of your screenshot will be saved on your desktop.
• Command+Shift+4+Ctrl
  This command only has a minor variation from the above command, which allows you to use the screenshot right away, by saving it on the clipboard instead of your desktop.

Having the knowledge about taking a screenshot will surely be useful in many ways, especially when you need to preserve contents of your screen for further use.
By Suketu Mehta (Source)

Computer Screen Goes Black

When your computer screen goes black randomly, you are left helpless as nothing is visible on your monitor screen. This, for most, is a reason for panic as you may not know where to start the troubleshooting process. Like most other computer monitor problems, here too the main reason is either with the video card or the power supply to the monitor. Sometimes, your computer screen could also go black during start up even before it boots. Before you rush to a qualified technician, follow instructions given below to find out the possible cause and if you are lucky, you can solve the problem yourself at home too.

Reasons Why Computer Screen Goes Black

Moisture
The most common reason why your computer screen goes black is moisture. Whenever the computer monitor is put in a humid environment, water tends to condense and collect on the insides of the monitor. Due to this the computer screen goes black and absolutely nothing is visible on it. A good way to solve this problem is by leaving the monitor alone for a while, so that any moisture accumulated evaporates.

Defective Graphics Card
Another common reason for you computer screen to go black is a defective graphic or video card. A good way to figure this out is by connecting a new monitor to the CPU, and checking if the problem still persists. If the screen stops appearing black, then the problem is something else; and if the screen does continue appearing black, then you need to repair or replace your graphics card.

Defective RAM
Though not very common, there is a possibility your computer screen goes black after startup due to a faulty RAM. Bad RAM modules can prevent the computer from booting properly, even through the basic BIOS setup. It is extremely difficult to detect this problems as you might have to install the RAM in another computer and then check.

Lack of Tight Connections
Loose connections are another reason why your computer screen could go black. Check both, the connection from the monitor to the main power supply and the connection between the video card and your monitor. Ensure these connections are tight and proper before you go on checking other parts of the computer.

Motherboard Short Circuit
A short circuit in the computer motherboard could also cause the monitor screen to go black. This is the worst possible reason as the only choice left with you is to replace your motherboard with a new one altogether. Even though chances are less, there is a possibility this could happen. A good way to prevent this problem would be ensuring all connections on the motherboard are proper and tight, without any loose ends.

What to do When Your Computer Screen Goes Black on Startup?

Check For Bleeps
The first thing you must do when your computer screen goes black on startup after booting, is to hear the bleeping sound it makes. In case you hear only a single short bleep, proceed to the next step. But if you hear a long bleep or multiple bleeping sounds, it is an indications of a major problem and the best thing to do is to get your computer check from a technically qualified person.

Examine Monitor Cables
Since a loose connection of monitor cables can be the cause of the problem, check the connections. The power connection as well as the video card connection should be secured and firm.

Examine All Enhancement Cards
The video card and all other graphic cards should be firmly fixed in their respective slots. Check all these connections on the motherboard by opening up the CPU case and secure them if necessary. Although the video card is the one you are concerned with, any other ill-fitted graphic or sound cards can also be the reason why your computer screen goes black on startup.

Examine Power Supply Connections
This is the last thing you need to check. All power supply connections of the computer including the CPU, the monitor and other external devices must be tightly connected and secured.
If your computer screen goes black even after trying out the troubleshooting instructions given above, then it is time you get your machine checked from a qualified technician. It could be a major problem and a proper, prompt repair will prevent it from aggravating further.

Mouse Not Working

The mouse, or should we call the hands of your computer! Without this little equipment your computer is rendered helpless to be worked upon, well, unless of course, you are very savvy with keyboard shortcuts. However, you would agree that using the keyboard as a substitute for the 'easy-to-use' mouse gets tedious and not something which you would like to do every time. Moreover not everything that needs to be executed using the mouse, can be done using the keyboard. So, this leaves us with one basic inference that the mouse is one of the most vital peripherals of a computer. Sometimes, this important part of your computer may get 'ill' or suffer from different physical problems and when it does, it suffers from a condition known as 'mouse not working', as we have mentioned above. So what could be done to help the computer mouse recover and get back to its normal function. Here's what you should know and do...

Mouse Not Working Properly

Knowing why mouse stops working and correcting the errors may provide you with the solution for the problem. So here are some common possibilities which can cause a mouse to stop working.

The most common problem which can cause the ailment of 'mouse not working' is a loose connection or connection to the wrong port of the CPU. If it is so, then detach the cord of the mouse and plug it in. If you are using a PS/2 style mouse, then you might require to restart your computer after unplugging and plugging the mouse cord. If its a USB mouse, then you need not do the same. If the wire of the mouse is twisted, bent or damaged in any way, then even in this case it might not function.

Another method of diagnosing the problem of 'mouse not working' is to try using a different mouse in the PC. Similarly, try your mouse in a different PC and see if it works. Most of the times, people accidentally connect the cord of the mouse to the port of the keyboard. But in this case, it is easy to identify the error as even the keyboard will not function.

One more among the common causes which make the mouse cease to function arises due to some problems with the serial port, when you are using a serial mouse. The 'mouse not working' problem may also arise after you get your computer system upgraded. One reason behind this may be the old cable that attached from the serial port connectors to the motherboard headers are left in place. These cables are not universal and so this implies that you might have the wrong kind installed on the motherboard.

A PS/2 style mouse uses what is known as IRQ12. In some cases, it has been found that this creates a resource conflict (when two different devices are both trying to use a system resource like an interrupt request line, DMA channel or I/O address) with another device. Using a PS/2 style mouse on a serial port also makes the mouse useless.

So, these were some of the most basic problems related to 'mouse not working' ailment of your computer. The above description goes the same even for the condition of 'mouse not working' on laptops. However, as I said these are the basic problems and there might be many more and complex ones too. So, if you are not able to cure the ailment of your mouse, then you should consider paying a visit to a doctor of computers!
By Rajib Singha