What is a Computer Motherboard?

A computer motherboard is nothing but the circuit board or the circuit which controls the entire functioning of the computer. Let us try to understand it this way. All the components that form your computer are connected to the computer motherboard. The computer processor, which is the most important component of your computer, is mounted on the computer motherboard. All other components like the computer keyboard, computer monitor, computer mouse, hard drives, etc., are all connected to the computer motherboard through cables. Read more on what is a motherboard. Types of Computer Motherboards

Well, of course, after the discussion that we had above, you must be wondering how to determine a motherboard type. But before starting off with this process of describing the computer motherboard type, we need to understand, what are the different ways of classifying or rather differentiating computer main-boards.

Classification on the Basis of Type of Processor

This way of differentiating computer motherboards is based on motherboard socket types. In short, the CPUs that are available in the current market are compatible to specific motherboards. Let us try to understand the different CPU specific computer motherboards in a little more detail.

Socket A Motherboards

These motherboards are meant for the AMD and Durons processors. The Socket A motherboard is also known as Socket 464 motherboard. The CPU socket in the motherboard has 462 pins and it comes in a PGA (Pin Grid Array) packaging. The bus speed of this type of motherboard is 100 to 200 MHz.

Meant for Intel P-III and Celeron processor, this motherboard comes for CPUs with 370 pins. It can also support VIA Cyrix III and VIA C3 processors. The bus speed for this type of motherboard is 66 to 133 MHz and it also comes in a PGA package.

Socket 378 Motherboards

This type of motherboard is meant for the Pentium 4 processors. It also comes in a PGA package and has 478 pins. The bus speed is 100 to 200 MHz. This motherboard can also support Intel Pentium 4EE and Intel Pentium M processor. This type of motherboard is also known as Socket N motherboard.

Socket T Motherboards

Also known as LGA 775, this type of motherboard is meant for Intel Core 2 Duo, Intel Core 2 Quad and Inel Xeon processor. Of course, this motherboard can also support other Intel processors such as the Celeron, P-4, Pentium D, Celeron D and Pentium XE processor. Its specifications include 775 pins and a very high bus speed of 1600 MHz. It also comes in a PGA package.

The Socket 939 is meant mainly for the AMD family. It can support AMD processors like the Athlon 64, Athlon 64 FX, Athlon 64 X2 and Opetron. It has 939 pins and can have a bus speed from 200 to 1000 MHz. Just like the other computer motherboard types described above, it also comes in a PGA package.

Socket AM3 Motherboards

Socket AM3 is among the most recently developed motherboards. Introduced in 2009, this motherboard is meant for the AMD Phenom II and AMD Athlon II processors. It has 941 pins and a bus speed range of 200 to 3200 MHz. The packaging for Socket AM3 motherboard is PGA.

The Socket H or LGA 1156 is another recent motherboard that has been introduced in the year 2009 and is meant for the Intel Core i3, Intel Core i5 and Intel Core i7processors. It has 1156 pins and comes in LGA (Large Grid Array) packaging.

What I have mentioned above are the most common motherboard types. Besides the different types of computer motherboard types given above, there are other computer motherboards too. For example, the Socket F motherboard meant for the AMD Opteron and AMD Athlon 64 FX and the Socket M motherboard meant for the Intel Core Solo, Intel Dual Core and Intel Core Duo processors.

Motherboard Type Based on Dimensions

The dimensions of a motherboard, also known as the form factor, is another way of distinguishing between the different motherboard types. The different types of motherboards based on this form factor can be listed as under. ATX Motherboards

The ATX (Advanced Technology Extended) motherboard has a length of 12 inches and a width of 7.5 inches. The I/O ports and USB ports meant for the motherboard are integrated directly into it. The bus speed in ATX motherboard is 100 MHz. This board is mainly meant for the Intel processors.

Full AT Motherboards

This was the first type of motherboard, which were 12 inches wide and 11 inches long. This motherboard suffered from a lot of problems like access to components was cumbersome and most importantly, the heating problem.

Baby AT Motherboards

With a dimension of 10 by 8.5 inches, this motherboard is meant for the classic Pentium processors. The DIN keyboard connector at the top right corner of this motherboard makes recognizing this motherboard a relatively simple task.

Normally, the documentation that contains the information of the motherboard type of your computer is the best way for determining your computer motherboard type. If in case you do not have access to those documents, you can go to the system devices tab located in the device manager and try to find out your motherboard type. You can also run msinfo32 to find out the information about the installed hardware. There are various other third party programs too, which you can use for determining the motherboard type. If in case you are not working on the computer, you can simply open the cabinet of your CPU and check out for a label on the computer's motherboard. It is usually present in the upper left or right corner of the motherboard. If at any other position, you may have to disconnect certain components to view the same. Another way of finding out the motherboard type is if you can locate the FCC (Federal Communications Commissions) identification number of the motherboard and perform a search on the type of motherboard using the same. Read more on tips for choosing a computer motherboard.

The type of motherboard used for your computer is also used for determining various other factors. For example, DDR SDRAM is the fastest of all the different types of RAM and only Socket A motherboards can be used for the same. Similarly, SDRAM is compatible with Socket 370 and RD RAM with socket 478. Similarly, the type of motherboard determines various other factors too. With this, I end my article. Hope this article on computer motherboard types proves to be of help to you.

Modem

MODEM 

 1. Short for MODulator/DEModulator, the first Modem known as the Dataphone, which was first released by AT&T in 1960. It later became more common for home users when Dennis Hayes and Dale Heatherington released the 80-103A Modem in 1977.

The Modem is a hardware device that enables a computer to send and receive information over telephone lines by converting the digital data used by your computer into an analog signal used on phone lines and then converting it back once received on the other end. In the picture below, is an example of an internal expansion card .

Modems are referred to as an asynchronous device, meaning that the device transmits data in an intermittent stream of small packets. Once received, the receiving system then takes the data in the packets and reassembles it into a form the computer can use.

Stop 1 bit

Data 8 bits

Start 1 bit

Stop 1 bit

Data 8 bits

Start 1 bit

Packet 10 bits

Packet 10 bits

The above chart represents how an asynchronous transmission would be transmitted over a phone line. In asynchronous communication, 1 byte (8 bits) is transferred within 1 packet, which is equivalent to one character. However, for the computer to receive this information, each packet must contain a Start and a Stop bit; therefore, the complete packet would be 10 bits. In the above chart is a transmission of the word HI, which is equivalent to 2 bytes (16 bits).

Types of computer modems

Below are the three available versions of a computer Modem that can be used in computers.

Internal modem that connects to a PCI slot inside a newer desktop computer or ISA slot on an older computer. The Internal Modem shown at the beginning of this document is an example of a PCI modem.

External modem is located within a box and is hooked up externally to the computer, usually the Serial Ports or USB port. The picture is an example of an external USRobotics Modem.

Removable modem that is used with older laptops PCMCIA slot and is removed when you need the PCMCIA slot for another device, but are not planning on using the modem.

2. A Modem or Broadband Modem is also used to refer to the hardware device that connects a computer or router to a broadband network. For example, a Cable Modem and DSL Modem are two examples of these types of Modems.

Network Topologies

NETWORK TOPOLOGIES 

A Network Topology is the way computer systems or network equipment connected to each other. Topologies may define both physical and logical aspect of the network. Both logical and physical topologies could be same or different in a same network.

Point-to-point

Point-to-point networks contains exactly two hosts (computer or switches or routers or servers) connected back to back using a single piece of cable. Often, the receiving end of one host is connected to sending end of the other end and vice-versa.

[Image: Point-to-point Topology]

If the hosts are connected point-to-point logically, then may have multiple intermediate devices. But the end hosts are unaware of underlying network and see each other as if they are connected directly.

Bus Topology

In contrast to point-to-point, in bus topology all device share single communication line or cable. All devices are connected to this shared line. Bus topology may have problem while more than one hosts sending data at the same time. Therefore, the bus topology either uses CSMA/CD technology or recognizes one host has Bus Master to solve the issue. It is one of the simple forms of networking where a failure of a device does not affect the others. But failure of the shared communication line make all other devices fail.

[Image: Bus Topology]

Both ends of the shared channel have line terminator. The data is sent in only one direction and as soon as it reaches the extreme end, the terminator removes the data from the line.

Star Topology

All hosts in star topology are connected to a central device, known as Hub device, using a point-to-point connection. That is, there exists a point to point connection between hosts and Hub. The hub device can be Layer-1 device (Hub / repeater) or Layer-2 device (Switch / Bridge) or Layer-3 device (Router / Gateway).

[Image: Star Topology]

As in bus topology, hub acts as single point of failure. If hub fails, connectivity of all hosts to all other hosts fails. Every communication happens between hosts, goes through Hub only. Star topology is not expensive as to connect one more host, only one cable is required and configuration is simple.

Ring Topology

In ring topology, each host machine connects to exactly two other machines, creating a circular network structure. When one host tries to communicate or send message to a host which is not adjacent to it, the data travels through all intermediate hosts. To connect one more host in the existing structure administrator may need only one more extra cable.

[Image: Ring Topology]

Failure of any host results in failure of the whole ring. Thus every connection in the ring is point of failure. There exists methods which employs one more backup ring.

Mesh Topology

In this type of topology, a host is connected to one or two or more than two hosts. This topology may have hosts having point-to-point connection to every other hosts or may also have hosts which are having point to point connection to few hosts only.

[Image: Full Mesh Topology]

Hosts in Mesh topology also work as relay for other hosts which do not have direct point-to-point links. Mesh technology comes into two flavors:

• Full Mesh: All hosts have a point-to-point connection to every other host in the network. Thus for every new host n(n-1)/2 cables (connection) are required. It provides the most reliable network structure among all network topologies.
• Partially Mesh: Not all hosts have point-to-point connection to every other host. Hosts connect to each other in some arbitrarily fashion. This topology exists where we need to provide reliability to some host whereas others are not as such necessary.

Tree Topology

Also known as Hierarchical Topology is the most common form of network topology in use present day. This topology imitates as extended Star Topology and inherits properties of Bus topology.
This topology divides the network in to multiple levels/layers of network. Mainly in LANs, a network is bifurcated into three types of network devices. The lowest most is access-layer where user’s computer are attached. The middle layer is known as distribution layer, which works as mediator between upper layer and lower layer. The highest most layer is known as Core layer, and is central point of the network, i.e. root of the tree from which all nodes fork.

[Image: Tree Topology]

All neighboring hosts have point-to-point connection between them. Like bus topology, if the root goes down, the entire network suffers. Though it is not the single point of failure. Every connection serves as point of failure, failing of which divides the network into unreachable segment and so on.

Daisy Chain

This topology connects all its hosts in a linear fashion. Similar to Ring topology, all hosts in this topology are connected to two hosts only, except the end hosts. That is if the end hosts in Daisy Chain are connected then it represents Ring topology.

[Image: Daisy Chain Topology]

Each link in Daisy chain topology represents single point of failure. Every link failure splits the network into two segment. Every intermediate host works as relay for its immediate hosts.

Hybrid Topology

A network structure whose design contains more than one topology is said to be Hybrid Topology. Hybrid topology inherits merits and demerits of all the incorporating topologies.

[Image: Hybrid Topology]

The above picture represents an arbitrarily Hybrid topology. The combining topologies may contain attributes of Star, Ring, Bus and Daisy-chain topologies. Most WANs are connected by means of dual Ring topology and networks connected to them are mostly Star topology networks. Internet is the best example of largest Hybrid topology