Computer Hardware Peripherals — Introduction to Information and Communication Technology (2024)

Introduction¶

A peripheral is a piece of computer hardware that is added to a computer inorder to expand its abilities. The term peripheral is used to describe thosedevices that are optional in nature, as opposed to hardware that is eitherdemanded or always required in principle. There are all different kinds ofperipherals you can add your computer. The main disctinction among peripheralsis the way they are connected to your computer. They can be connectedinternally or externally.

Buses¶

A bus is a subsystem that transfers data between computer components inside acomputer or between computers. Unlike a point-to-point connection, a bus canlogically connect several peripherals over the same set of wires. Each busdefines its set of connectors to physically plug devices, cards or cablestogether. There are two types of buses: internal and external. Internal busesare connections to various internal components. External buses are connectionsto various external components. There are different kinds of slots thatinternal and external devices can connect to.

Internal¶

Types of Slots¶

There are many different kinds of internal buses, but only a handful of popularones. Different computers come with different kinds and number of slots. It isimportant to know what kind and number of slots you have on your computerbefore you go out and by a card that matches up to a slot you don’t have.

PCI¶

PCI (Peripheral Component Interconnect) is common in modern PCs. This kind ofbus is being succeeded by PCI Express. Typical PCI cards used in PCs include:network cards, sound cards, modems, extra ports such as USB or serial, TV tunercards and disk controllers. Video cards have outgrown the capabilities of PCIbecause of their higher bandwidth requirements.

PCI Slots

PCI Express¶

PCI Express was introduced by Intel in 2004. It was designed to replace thegeneral-purpose PCI expansion bus and the AGP graphics card interface. PCIexpress is not a bus but instead a point-to-point conection of serial linkscalled lanes. PCI Express cards have faster bandwidth then PCI cards which makethem more ideal for high-end video cards.

PCMCIA¶

PCMCIA (also referred to as PC Card) is the type of bus used for laptopcomputers. The name PCMCIA comes from the group who developed the standard:Personal Computer Memory Card International Association. PCMCIA was originallydesigned for computer memory expansion, but the existence of a usable generalstandard for notbeook peripherals led to many kinds of devices being madeavailable in this form. Typical devices include network cards, modems, and harddisks.

AGP¶

AGP (Accelerated Graphics Port) is a high-speed point-to-point channel forattaching a graphics card to a computer’s motherboard, primarily to assist inthe acceleration of 3D computer graphics. AGP has been replaced over the pastcouple years by PCI Express. AGP cards and motherboards are still available tobuy, but they are becoming less common.

AGP Slot

Types Of Cards¶

Video Card¶

A video card (also known as graphics card) is an expansion card whose functionis to generate and output images to a display. Some video cards offer addedfunctions, such as video capture, TV tuner adapter, ability to connect multiplemonitors, and others. Most video cards all share similar components. Theyinclude a graphics processing unit (GPU) which is a dedicated microprocessoroptimized for 3D graphics rendering. It also includes a video BIOS thatcontains the basic program that governs the video card’s operations andprovides the instructions that allow the computer and software to interfacewith the card. If the video card is integrated in the motherboard, it may usethe computer RAM memory. If it is not it will have its own video memory calledVideo RAM. This kind of memory can range from 128MB to 2GB. A video card alsohas a RAMDAC (Random Access Memory Digital-to-Analog Converter) which takesresponsibility for turning the digital signals produced by the computerprocessor into an analog signal which can be understood by the computerdisplay. Lastly, they all have outputs such as an HD-15 connector (standardmonitor cable), DVI connector, S-Video, composite video or component video.

Graphics Card

Sound Card¶

A sound card is an expansion card that facilitates the input and output ofaudio signals to/from a computer under control of computer programs. Typicaluses for sound cards include providing the audio component for multimediaapplications such as music composition, editing video or audio,presentation/education, and entertainment. Many computers have soundcapabilities built in,, while others require additional expansion cards toprovide for audio capability.

Network Card¶

A network card is an expansion card that allows computers to communicate over acomputer network. It allows users to connect to each other either by usingcables or wirelessly. Although other network technologies exist, Ethernet hasachieved near-ubiquity for a while now. Every Ethernet network card has aunique 48-bit serial number called a MAC address, which is stored in ROMcarried on the card. You can learn more about networking in the introduction tonetworking lesson.

Network Card

External¶

Types of Connections¶

USB¶

USB (Universal Serial Bus) is a serial bus standard to interface devices. USBwas designed to allow many peripherals to be connected using a singlestandardized interface socket and to improve the plug-and-play capabilities byallowing devices to be connected and disconnected without rebooting thecomputer. Other convient features include providing power to low-consumptiondevices without the need for an external power supply and allowing many devicesto be used without requiring manufacturer specific, individual device driversto be installed. USB is by far the dominating bus for connecting externaldevices to your computer.

USB Connectors

Firewire¶

Firewire (technically known as IEEE 1394 and also known as i.LINK for Sony) isa serial bus interface standard for high-speed communications and isochronousreal-time data transfer, frequently used in a personal computer. Firewire hasreplaced Parallel ports in many applications. It has been adopted as the HighDefinition Audio-Video Network Alliance (HANA) standard connection interfacefor A/V (audio/visual) component communication and control. Almost all moderndigital camcorders have included this connection.

Firewire Cable

PS/2¶

The PS/2 connector is used for connecting some keyboards and mice to a PCcompatible computer system. The keyboard and mouse interfaces are electricallysimilar with the main difference being that open collector outputs are requiredon both ends of the keyboard interface to allow bidirectional communication. Ifa PS/2 mouse is connected to a PS/2 keyboard port, the mouse may not berecognized by the computer depending on configuration.

PS/2 Ports

Devices¶

Removable Storage¶

The same kinds of CD and DVD drives that could come built-in on your computercan also be attached externally. You might only have a CD-ROM drive built-in toyour computer but you need a CD writer to burn CDs. You can buy an external CDwriter that connects to your USB port and acts the same way as if it wasbuilt-in to your computer. The same is true for DVD writers, Blu-ray drives,and floppy drives. Flash drives have become very popular forms of removablestorage especially as the price of flash drives decreases and the possible sizefor them increases. Flash drives are usually USB ones either in the form USBsticks or very small, portable devices. USB flash drives are small, fast,removable, rewritable, and long-lasting. Storage capacities range from 64MB to32GB or more. A flash drive does not have any mechanically driven parts so asopposed to a hard drive which makes it more durable and smaller usually.

USB Flash Drive

Non-removable Storage¶

Non-removable storage can be a hard drive that is connected externally.External hard drives have become very popular for backups, shared drives amongmany computers, and simply expaning the amount of hard drive space you havefrom your internal hard drive. External hard drives come in many shapes andsizes like flash drives do. An external hard drive is usually connected by USBbut you can also have a networked hardrive which will connect to your networkwhich allows all computers on that network to access that hard drive.

Input¶

Input devices are absolutely crucial to computers. The most common inputdevices are mice and keyboards which barely every computer has. A new popularpointing device that may eventually replace the mouse is touch screen which youcan get on some tablet notebooks. Other popular input devices includemicrophones, webcams, and fingerprint readers which can also be built in tomodern laptops and desktops. A scanner is another popular input device thatmight be built-in to your printer.

Webcam

Output¶

There are lots of different kinds of output devices that you can get for yourcomputer. The absolute most common external output device is a monitor. Othervery popular output devices are printers and speakers. There are lots ofdifferent kinds of printers and different sizes of speakers for your computer.Monitors are connected usually through the HD-15 connector on your video card.Printers are usually connected through a USB port. Speakers have their ownaudio out port built-in to the sound card.

Monitor

Exercises¶

Worksheets¶

Worksheet: Define Key Terms

Labs¶

Identify computer hardware peripherals