# Computer Hardware Types

This is a lesson in the course Introduction to Computers, which is a part of The School of Computer Science

## Hardware Details

Hardware refers to the physical elements of a computer. Also referred to as the machinery or the equipment of the computer. Examples of hardware in a computer are the keyboard, the monitor, the mouse and the processing unit However, most of a computer's hardware cannot be seen; It's inside the computer case.
I/O lets the computer talk with the world around it. Sometimes its necessary to add functionality to a computer to keep it up to date, or make it better. The amount of I/O a computer has can be changed, by adding expansion cards that support I/O. A graphics card can be added to a computer to let it talk with a display, or a WiFi card can be added, which will let a computer talk to other computers without a connecting wire. Sometimes functionality can be added through a universal port, a port that supports multiple kinds of I/O. USB, FireWire, and Thunderbolt (Types of I/O) support multiple data types. Your keyboard, mouse, and monitor all connect to a computer's I/O.
CPUs or processors perform computations. They do the math for your calculator application, they compare the size of numbers; people have likened the CPU to the "brain" of a computer.
Memory is what allows a computer to remember things. Similar to human memory, there's long term memory (a hard disc or optical media (like a CD)) and short term memory (RAM). When a computer is turned off, it forgets everything in the RAM, so the computer saves everything it knows it will need later on in the long term memory. The short term memory is easier to use because it can do I/O faster, so when a data is needed by the CPU, it's sent from the hard disk drive (HDD) to the RAM. The short term memory lives on RAM, while the long term memory is in the hard disk drive (HDD). Optical disks let you change certain parts of the memory, it's kind of like having a book or notebook that you might read and get information from.
The motherboard is a piece of hardware that makes connections in the right places between all of the other components in a computer. It tells data where it should go. When the CPU is finished processing some data, it might say to the CPU, OK, put this in the HDD, and the motherboard will figure out where the HDD is and send the data there.

## Introduction to Motherboard

A motherboard is an electronic circuit board in a computer which interconnects hardware devices attached to it. At a minimum it includes one or more Central processing units, and the main processing activity of the computer takes place on it. However, other connected printed circuit boards may contain their own pre-processing or post-processing CPUs, to take some of the load off of the motherboard; these, together with other plug-in boards without CPUs, may be called "daughter boards." It was called a "mother" board in relation to these. A PC motherboard may have a series of sockets, allowing daughter boards to be plugged in directly. Other connectors on the motherboard allow communication through cables with various peripheral devices, both inside and outside the computer case.

## Ports

Ports are used by a motherboard to interface with electronics both inside and outside of the computer.

### Serial

A legacy technology, serial ports were most often used to connect a mouse or modem. By circa 2000, most personal computers stopped relying on serial ports and were replaced by PS/2 and/or USB ports. Serial ports are sometimes still used for specialized applications such as industrial automation systems, scientific instruments, and point of sale systems.

### PS/2

PS/2 ports (now outdated) were for connecting peripherals such as your keyboard and mouse to the computer. PS/2 based mice and keyboards have now been replaced by USB ports as the popular standard. This trend for USB over PS/2 started in circa 2004.

### Parallel

Parallel ports are used to connect other peripherals such as joysticks, and more commonly, printers. Similar to the serial port, this technology is slowly being phased out in favour of USB. Parallel ports can still be found in many motherboards today.

### Small Computer System Interface (SCSI)

Pronounced "scuzzy", this was used primarily as a connection interface for tape drives and hard disk drives. SCSI has been superseded in favour of newer and cheaper technologies such as USB and Firewire.

### USB

USB, short for Universal Serial Bus, is an industry standard developed in the mid-1990s that defines the cables, connectors and communications protocols used in a bus for connection, communication, and power supply between computers and electronic devices. A bus is a communication system that transfers data between components inside a computer, or between computers.

### Firewire

Technically known as the IEEE 1394 interface, but dubbed by Apple as Firewire, this connection medium hoped to surpass USB in terms of speed and popularity. While it did outperform USB v2 in speed tests, uptake was very limited due to the existing widespread use of USB.

## Slots

Slots are an opening in a computer where a circuit board can be inserted to add new capabilities. All personal computers contain expansion slots for adding more memory, graphics capabilities, and support for special devices. Expansion slots come in different flavours, which will be described below. An alternative explanation for expansion slots can be found here.

### Graphics card

Graphic cards are also called video cards or a video adapter. They are in all PCs. Graphic cards convert signals into video signals so the images can be displayed on the monitor. While many graphics cards are integrated into the CPU these days, enthusiasts will invest in standalone graphics cards with stronger and more powerful processing capabilities. This allows for heavy image editing, or better rendering and framerates in computer games.
Graphics cards are designed to offload rendering from the CPU. Graphics cards are powered by the motherboard and require a PCIX or PCIX 2.0 slot to install. Some cards require more power and thus will need a 6-8 pin connector that runs directly to the power supply. Graphics cards also include on board memory for efficient rendering. Typical sizes include 128-1024mb of memory. Today, high end graphics cards have multiple core processors that are largely parallel to increase texture fill and process more 3D objects in real time.
Graphics Card on Wikipedia

### Sound card

A sound card, also referred to as an audio card facilitates the input and output of audio signals to and from a computer under the control of computer programs. Sound cards for computers were uncommon until 1988, which left the single internal PC speaker as the only way early PC software could produce sound and music.
Sound Card on Wikipedia.

### Network Interface Cards (NICs)

Network Interface Cards can be a network card, network adapter, LAN Adapter or NIC (network interface card). They are a piece of computer hardware designed to allow computers to communicate over a computer network. It is used for fault communication via cable. Data is transmitted over a cable network. The NIC connects computers and other devices such as printers. Many modern motherboards have NICs built in by default.
NICs on Wikipedia

### PC Card

A PC Card (originally PCMCIA Card) is a device that uses a specific peripheral interface designed for laptop computers.
PC Card on Wikipedia

## See Also

* Computer Hardware
* IT Fundamentals