Do You Really Know Your UTP Cable Configuration?
EIA/TIA wiring standards were first published in 1991 and have been evolving ever
since. The EIA/TIA-568 standard defines the specification of the
cable to be used as well as some installation rules. The latest
version of the EIA/TIA standard is 568B, which contains some minor
enhancements to the original 1991 standard. The most popular is
Category 5, the highest-quality UTP cable. It is tested at 100 MHz,
allowing it to run high-speed protocols such as 100 Mbps Fast Ethernet and
FDDI. Category 5 cable also uses either 22 or 24 AWG unshielded
twisted pair wire with impedance of 100 ohms.
The IEEE has defined three new physical layers for 100
Mbps Fast Ethernet. By far, the 100Base-TX is the most popular
one. However, the IEEE also demands rigid compliance of how the
cable is installed with RJ-45 connector. Otherwise, you will have
high-speed data transmission problem - NEXT. NEXT is the coupling of
signals from one twisted pair to another. NEXT is undesired because
it represents unwanted spillover from one pair to other. The result
is corrupted data or no connection at all.
Even you are using Cat 5 cable with 4 twisted pair
wires, it doesn’t mean that the cable is 100% compliant with EIA/TIA
standard if it is not connected to RJ-45 in the way it should be.
The Straight-through cable (”Patch cable”) connection should be:
Pin 1 and 2 are connected to same twisted pair wirePin 3 and 6 are connected to same twisted pair wirePin 4 and 5 are connected to same twisted pair wirePin 7 and 8 are connected to same twisted pair wire
PIN Pair Cable
Color1| —\ 1 T2 White/Orange RJ-45 Plug with clip facing down
2| —/ 2 R2 Orange 3| ——\ 3 T3 White/Green 4| —\ \ 4 R1 Blue 5| —/ / 5 T1 White/Blue 6| ——/ 6 R3 Green 7| —\ 7 T4 White/Brown 8| —/ 8 R4 Brown If you have the problem mentioned above, please check
your cable to see if it is compliant with the standard. If not just
simply cut out the existing RJ-45 connectors and replace them in the RIGHT
way!Here is the pin-out for Crossover cable
(”Uplink cable”):
Point
APoint
BTR+ Pin 1 —– Pin 3 RCV+ TR- Pin 2 —– Pin 6 RCV- RCV+ Pin 3 —– Pin 1 TR+ RCV- Pin 6 —– Pin 2 TR-
In normal wiring, the transmit pair is in ORANGE and the
receive pair is in GREEN. The other two pairs, blue and brown, are
ignored.There is also another wiring standard - EIA/TIA-568A.
Technically, there is no different between 568A and 568B in Ethernet
applications. However, if Ethernet system combined with phone system
is being used, most of the people will prefer 568A standard due to the
fact that 568B may have backward compatibility problem with standard
Universal Service Order Codes (USOC) hardware, which are commonly used in
the telephone infrastructure.
568A and 568B Pin-out 568A
568B
White/Green –\ White/Orange –\ Pin 1 Green –/ Orange –/ Pin 2 White/Orange ——\ White/Green ——\ Pin 3 Blue –\ \ Blue –\ \ Pin 4 White/Blue –/ / White/Blue –/ / Pin 5 Orange ——/ Green ——/ Pin 6 White/Brown –\ White/Brown –\ Pin 7 Brown –/ Brown –/ Pin 8
How to install a Motherboard
The first thing you should do is unpack your ATX case. Take off the cover of your case so that you can access the inside. Place the case on a desk so that you are looking down towards the open case. Your case should come with motherboard mounting screws. If your ATX back plate it not already fitted you can fit it by placing your plate near the ATX back plate cut out and pushing the plate outwards, it should clip on.
Now place your motherboard on top of the mounting screw holes. Make sure your ATX devices on the motherboard such as PS/2 and parallel port are facing towards ATX back plate cut out. Gently push your motherboard towards the cut out, every devices should fit easily into its corresponding cut out, as shown below.
<img class=”alignnone size-medium wp-image-88″ title=”atx_back” src=”http://www.computerhardware.net84
Blu Ray Writer
Bluray writers are the latest storage medium. It is deigned to replace DVD-Writers as it can store 25GB of data on single layer bluray disc or 50GB on a dual layer disc. Becuse bluray is new technology it is still very expensive to have mass market appeal. If you need to backup or archive huge amount of data it would make an excellent backup device.
Cable TV Card
Digital Cable Card (DVB-C) allows you watch cable TV on your PC. In many countries you are given the choice of free-to-air cable TV. It offers an alternative to digital terestial TV via arial.
There are many commercial and free DVB software that allows you to watch, record, or use your PC as a PVR.
TV Card
A TV card gives you the option of watching TV on your monitor. TV cards are quite useful as it offers more than just watching TV. You can connect your VCR to the TV card so that you can watch video’s too. One of the useful things about having a TV card is that you can use it for capturing Video. Using the necessary software you can capture video in various format such AVI or MPEG files. One of the popular TV card is Haupauge WinTV PCI as shown below.
Older TV cards were all analogue device. Now you can get Digital TV cards which allows you to view Digital terrestrial TV channels. You can even get Digital Satellite and Cable TV cards.
Satellite Card
Digital satellite cards (DVB-S) are designed to allow you to watch Satellite TV or get high speed broardband via Satellite. You can connect the card to a satellite dish using the standard F-socket just like a deicated satellite box. Once installed and the dish is alligned to your chosen satellite like Astra, Hotbird etc you can use a DVB software to watch your favaourate satellite channels on you PC.
There a quite a few manufacturers of satellite cards. Some of the popular brands are Hauppage, Technisat and Technotrend.
CD/DVD Writer
CD Writer / DVD Writer is a very good option for a backup device. It allows you to backup the contents of your HDD onto a CD-R, CD-RW & DVD-R disc. It also allows you to backup your existing application CD’s. As blank CD’s are very cheap, it is an affordable backup device.
Like all other PC hardware a CD/DVD Writer comes in various speed. A 32 speed drive can write a full 650MB CD in around 4 mins and a 52 speed drive can write it in around 3 mins and so on. CD-ReWritable’s are available in IDE and SCSI interface. You will require a SCSI card if choose to get a SCSI model.
CD / DVD Writer is more than just backup device, you can use it to create your own Audio CD, Photo CD, Video CD etc. You can also use your CD or DVD meida just the way you use hard drive, using the usual drag and drop file copy. Most CD/DVD writers are bundled with software which can perform all the tasks I have mentioned.
Monitor
It is important that you get a quality monitor that is comfortable to view. Monitors come is various sizes and refresh rate. 17″ monitor are becoming entry standard monitor. 15″ monitors are OK if you are running it at a low resolution and not using it for long hours. As monitor prices have dropped in the recent months it is recommended that you consider a 17″ or 19″ monitor. You can run these monitors at higher resolution and refresh rate, which means they are more comfortable to view and you can work with them for long hours. Monitors are measured diagonally. If a monitor is 17″ it does not mean that it is the actual viewable area. Some 17″ comes with a viewable area of 16″ which is good where as others can be as low as 15.6″. Monitors consist of thousands of pixels (the tiny dots you see on the screen). Smaller pixels produces high definition sharp display. Settle for something which is at least 0.25 mm dot pitch. If you purchase a 17″ monitor make sure it can handle refresh rate of at least 85 Hz at 1024 * 768 resolution. A 19″ monitor should handle at least 1280 * 1024 at 85 Hz.
Currently the most popular viewing device are TFT Flat panels. They are now more affordable than before. Most people prefer TFT Flat panels as they save lot of desk space. They are also more comfortable view
PC Speakers
A quality sound card would not be much of a benefit without a decent pair of PC speakers. Most PC speakers are magnetically shielded so that it does not interfere with your monitor, but there are some budget speakers out there that are not shielded, so check before you buy. If you are just going to use the speakers for basic sound and music and are not one of those people who play CDs on a PC then you can get away with a budget PC speaker. However, if you play games and CD’s then you should consider a speaker system with a sub-woofer. These would produce high quality sound suitable for most tasks.
CD/DVD Rom
Nearly all operating systems and applications software comes on CD. It is therefore essential to have a CD-ROM drive for installing your applications. Certain programs requires the CD to be in the CD-ROM drive for that program to run. For example, various encyclopedia and games. CD-ROM can also be used for playing standard audio CD’s on your PC. If you are intending to watch DVD movies on your PC then you would require a DVD-ROM which can perform all the tasks of a CD-ROM as well as play DVD movies. CD-ROM’s come in various speeds, the faster drive, the faster it will install your applications. DVD drives specifies two types of speeds, one for the software installation and other for the DVD extraction. For example a DVD drive with 16×32x specification means that it is a 16 speed DVD and 32 speed CD. Some of the CD/DVD-ROM manufacturers include Toshiba, Poineer, Hitachi, LG and Samsung.
