Part 1 - Equipment
Tech Specs 1

LAN, Wi-Fi, AGP, RJ-45? What does it all mean? With the nearly endless list of abbreviations used in computing it is difficult to even know what to begin to look at, so here are the basics of the body of the computer, the motherboard and connections on it.

Motherboard – Also Main System Board, MoBo, system board, mainboard or logics board (Apple). The central circuitry of a digital computer that all other components connect to including RAM, HDD and CPU. All the cables, cards and peripherals plug into it one way or another. Included on the mother board are all the electronics for the different pieces of the computer to communicate and connect. Often there will be a list of ports included in the motherboard like LAN (Local Area Network), PS/2 (part 1), USB (part 1), serial and parallel ports (later articles), SATA and IDE (both discussed earlier), audio and video, AGP, PCI and ISA.

ISA (Industry Standard Architecture) is pretty much obsolete at this point but you may still run across it in some older PCs so I included it. It was an 8 or 16-bit slot on the motherboard that was used to connect peripherals. The 8-bit slot had 62 pins in one contiguous slot while the 16-bit ISA slot had an additional 36 pins added in a second slot section. As I said it is obsolete and included because you may still see an old Pentium-based system with it.

PCI, Peripheral Component Interconnect, the successor to ISA was all the rage in the late 1990s and has been superseded by PCI Express.

AGP, Accelerated Graphics Port or Advanced Graphics Port, is a newer higher speed connector found on motherboards, it is primarily for three-dimensional video cards, cards that help speed up the processing and display of games with 3-D environments. AGP will probably be completely obsolete soon as PCI Express is gaining popularity. There were several versions of the AGP port (1x, 2x, 4x and 8x) which was a little confusing as they had different signaling voltages as well as different speeds. The 8x data transfer speed is 2,133MB/s or 2GB/s but the signaling voltage was 0.8V which was different than the 4x ports which were 1.5V. Some ports are capable of multiple signaling voltages as well so be careful here because you could damage something by plugging a card into a slot with the wrong voltage. Each AGP version had a different ‘key’ pattern so that many cards will not fit into some wrong ports. By the end of 2007 there will probably be no new motherboards made with this port on it.

PCI Express (PCIe or PCI-E) is the latest in peripheral adapter connection technology. This means higher transfer speeds and results. It is capable, theoretically, of transferring 8GB/s with version 2.0, just announced earlier this month, to be capable of 16GB/s which is an insane amount of data. The connectors (usually yellow but not always) come in a variety of forms depending on the number of data-lanes it uses, each lane can transfer 250MB/s. The ports are 2, 4, 8, 16 or 32 lanes and have been designated 1x, 2x, 4x, 8x and 16x. The larger the number of lanes the faster the data transfer and the larger the physical connection is. Smaller cards will work in larger ports with this protocol as the power wiring is the same. Nearly all new video cards come in a PCI-E version now allowing for better data processing for 3-D applications and games.

LAN, Local area network, this is a built-in network adapter consisting of 8 connections. The cables are called category5 (Cat-5) network cable and have an adapter on the called an RJ-45 8-pin connector. The cable consists of 4 twisted wire pairs with each having differently colored insulation for identification purposes. This is the most popular connection for physical networking for home and offices. The connectors look like larger versions of the fixed-line telephone cables which have 4 pins and are called RJ-11. This is the basic physical or wired network.

Wi-Fi, wireless networking. Wi-Fi stands for Wireless Fidelity and is a protocol to ensure that wireless networking equipment works together. There are several speeds and versions, like everything. Wi-Fi all started with 802.11a which was slow and not very exciting for us. Then 802.11b came along but was quickly swallowed by 802.11g. But g was kind enough to be backward compatible with 802.11b. Neither can be used with 802.11a equipment. Without going into massively technical specifications at the moment let me just say that the frequencies of 802.11b/g are 2.4GHz to 2.487 GHz which means there can be interference from other devices, most notably 2.4GHz cordless telephones in the home. If a motherboard has built-in Wi-Fi then you will need an AP, Access Point, or wireless router to connect it to your home network. Standard APs and routers have a signal range of about 90 meters or 300 feet outdoors and 50 meters or roughly 150 feet indoors. The signal deteriorates rapidly if there are large metal surfaces or thick concrete walls between you and it. Multiple APs in a given area can also interfere with each other and create connection problems.

Many cities, notably New York, Seattle, Mountain View, California, and Ceske Budejovice, Czech Republic (where I live) have freely available wireless access points in the city. These can be accessed with any compatible Wi-Fi adapter.

Some mobile phones utilize 802.11p for portable network connectivity. Several video game devices also use Wi-Fi including the Nintendo Wii and DS, Sony’s PSP (Playstation Portable) and PS3 and Microsoft’s Xbox 360.

Ok I think that is enough for today. Next week I will continue looking at the ports and abbreviations attached to computer systems including parallel, serial, USB, COM and PS/2.

In a later article I will give you some advice on how to buy all of this equipment and how to find the information you need so you know which you should purchase. With all the different types and options it can be confusing at times and your most valuable ally in the process is information.

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