Moderation point: The connections between the components

The system unit, like the one above is the case that contains all the electronic components of any computer system.
The electronic components are considered internal hardware seeing that they are inside the system unit and you cannot see when you look at the computer.
These components inside the system unit are what process the data and really makes the computer work. Internal components are processors, motherboard, BIOS, power supply, fan and heat sink or cooling, hard drive configuration and controllers eg SATA, IDE, EIDE, ports eg USB, parallel, serial, internal memory eg RAM, ROM, cache and specialized cards eg network, graphic cards.

A computer peripheral is a device that is connected to a computer but is not part of the core computer architecture. The core elements of a computer are the central processing unit, power supply, motherboard and the computer case that contains those three components. Technically speaking, everything else is considered a peripheral device. However, this is a somewhat narrow view, since various other elements are required for a computer to actually function, such as a hard drive and random-access memory (or RAM).

Backing storage is needed because random access memory (RAM) is too small to hold all the programs and data at the same time the information in RAM is lost when the computer is turned off. The thing which actually holds the information is called the backing storage medium. The hardware used to transfer the information from memory to the media is called a backing storage device.

Backing storage: Performance factors eg data transfer rate, capacity

Data transfer rate is comparable to traffic flow. In theory, the wider the highway and the higher the speed limit, the more traffic moves through. Just like traffic flow, which can be affected by obstructions, accidents and poorly designed highways, data transfer rate is subject to problems as well. Basic definitions, units, typical data transfer rates and comparisons will help define what factors make up a data transfer rate.

When choosing what storage device to use, there a few factors you need to take into consideration:

• How much data the device will hold? What is its maximum capacity?
• How fast can the data be stored on the device?
• How fast the data can be retrieved from the device?

The performance of a system can be monitored using a profiler.

Backing storage: portable and fixed drives;

Fixed Hard Drive

A hard-drive built into the case of a computer is known as ‘fixed’. Almost every computer has a fixed hard-drive.

Fixed hard-drives act as the main backing storage device for almost all computers since they provide almost instant access to files (random access and high access speeds).

Portable Hard Drive

A portable hard-drive is one that is placed into a small case along with some electronics that allow the hard-drive to be accessed using a USB or similar connection.

Portable hard-drives allow very large amounts of data to be transportedfrom computer to computer.

Many portable music players (such as the iPod classic) contain tiny hard-drives. These miniature devices are just not much bigger than a stamp, but can still store over 100MB of data!

Backing storage: types eg disks, pen drives, optical media, flash memory cards;

• HDD
  This is the most current type of backup which means saving your data backup copy to the local hard drive.
• CD
  Backup to CD as a data protection approach has likely become very popular solution for last few years. CD discs, as backup media are quite inexpensive nowadays. More…
• DVD
  This option seems to be much more useful then backup to another media, because you can save large volumes of data at once. More…
• Floppy disk
  Such disks are successfully used for data backup but their storage space is highly restricted
• Zip disk
  Zip disks slightly larger than floppy disks. Because zip disks are inexpensive and durable, they are often used for backing up hard disks and for transporting large files.
• USB device
  It can be very useful for mobile users, who wish to always have the most up-to-date data with them, when going home from work for instance, or vice versa.
• Local network drives
• FTP
  You can store the backup copy of your data to FTP server almost as easily as you make it inside the local network. Specify an FTP site name and your username/password and Handy Backup will connect to the site and let you choose an FTP directory for your backup. You will be able to do this as if you would work with your local folders. You can even create a new directory and use it as a backup destination.

Peripherals: cabling eg coaxial, optical, twisted pair

Coaxial cable- A type of wire that consists of a centre wire surrounded by insulation and then a grounded shield of braided wire. The shield minimizes electrical and radio frequency interference.

 An optical fiber cable – is a cable containing one or more optical fibers that are used to carry light. The optical fiber elements are typically individually coated with plastic layers and contained in a protective tube suitable for the environment where the cable will be deployed. Different types of cable are used for different applications, for example long distance telecommunication, or providing a high-speed data connection between different parts of a building.

Twisted-pair cable- A type of cable that consists of two independently insulated wires twisted around one another. The use of two wires twisted together helps to reduce crosstalk and electromagnetic induction. While twisted-pair cable is used by older telephone networks and is the least expensive type of local-area network (LAN) cable, most networks contain some twisted-pair cabling at some point along the network. Other types of cables used for LANs include coaxial cables and fiber opticcables.

Peripherals: input devices eg camera, scanner;

Input devices allow us to enter raw data into a computer. The computer processes the data and then produces outputs that we can understand using an output device. Input devices can be manual or automatic.

Scanner

A scanner can be used to digitise images. They’re similar to a photocopier but they make a digital copy instead of a physical copy. They can also be used with optical character recognition (OCR) software to scan in text that is then editable.

Digital camera

A digital camera takes pictures and can usually record video too. The pictures it takes and the videos it records are stored in files. These files can be copied to a computer and later edited.

Peripherals: output devices eg monitor, printer, plotter;

The purpose of peripherals is to extend and enhance what a computer is capable of doing without modifying the core components of the system. A printer is a good example of a peripheral. It is connected to a computer, extends its functionality, but is not actually part of the core machine.

Plotters

A plotter can be used to produce high quality, accurate, A3 size or bigger drawings. They are usually used for Computer Aided Design (CAD) and Computer Aided Manufacture (CAM) applications, such as printing out plans for houses or car parts.

Printers

• Laser printers are quite expensive to buy and run but produce a high quality output and are quiet and fast.
• Ink-jet printers offer black and white or colour printing with reduced levels of quality and speed. Colour ink jet printers are cheaper to buy than colour laser printers.
• Dot matrix printers are not so common today. They are comparatively noisy and low quality but are cheap to run and are used when carbon copies or duplicates need to be made, such as for wage slips. Also, they are useful in dirty environments such as a garage because they are much sturdier than the other two types of printer.

Monitor

The most common output device is the monitor or VDU.

Modern monitors, where the case isn’t more than a few centimetres deep, are usually Liquid Crystal Displays (LCD) or Thin Film Transistors (TFT) monitors.

Older monitors, where the case is likely to be around 30 cm deep, are Cathode Ray Tube (CRT) monitors.

Many other types of output device exist including:

• speakers
• projectors
• buzzers
• motors
• switched outputs
• lights
• mechanical devices, eg a robot arm

Internal system unit components: specialized cards eg network, graphic cards

Specialised cards can be added to a system.

The graphics components are the part of your computer that control and enhance how graphics (pictures, videos, programs, animation, 3D) are displayed on your computer screen

A Network interface card, NIC, or Network card is an electronic device that connects a computer to a computer network, usually a LAN. It is considered a piece of computer hardware. Today, most computers are equipped with network cards.

The function of these components are to give people access to different things depending on the purpose of the card for example;

you could have a sound card. Its purpose is to make sound.
A video card’s purpose is to display video on your monitor.
A TV tuner card records television.
A DAC card gives control voltage to external devices.

Internal system unit components: internal memory eg RAM, ROM, cache;

ROM is memory that cannot be changed by a program or user. ROM retains its memory even after the computer is turned off. For example, ROM stores the instructions for the computer to start up when it is turned on again.

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RAM is a fast temporary type of memory in which programs, applications anddata are stored. Here are some examples of what’s stored in RAM:

• the operating system
• applications
• the graphical user interface (GUI)

If a computer loses power, all data stored in its RAM is lost.

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A CPU cache is a cache used by the central processing unit (CPU) of a computer to reduce the average time to access data from the main memory. The cache is a smaller, faster memory which stores copies of the data from frequently used main memory locations.

Internal system unit components: ports eg USB, parallel, serial;

Universal Serial Bus (USB) 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.

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A parallel port is a type of interface found on computers (personal and otherwise) for connecting peripherals. In computing, a parallel port is an parallel communication physical interface.

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A serial port is a serial communication physical interface through which information transfers in or out one bit at a time (in contrast to a parallel port). Throughout most of the history of personal computers, data was transferred through serial ports to devices such as modems,terminals and various peripherals.

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