What is a computer?

Plotter

A plotter is a device used for printing vector graphics. In the past, plotters were widely used in applications such as computer-aided design. A plotter is a device that draws pictures on paper based on commands from a computer. Plotters differ from printers in that they draw lines using a pen. As a result, they can produce continuous lines, whereas printers can only simulate lines by printing a closely spaced series of dots. Multicolour plotters use different-coloured pens to draw different colours. In general, plotters are considerably more expensive than printers. They are used in engineering applications and architecture where precision is mandatory as well as in the printing of posters.

Microfilm

These are the various peripherals and components that are associated with a computer system. The main specifications to consider when purchasing or assessing the quality or speed of the system are the processor unit and secondary storage devices. It is important to understand their purpose because they affect the performance of the computer.

Most computer systems are designed around a common word size. The bigger its word size, the more memory a computer can access. For example, on a 32-bit computer, the processor can manipulate 32-bit numbers. A computer’s word size affects its processing speed and memory capacity; so the bigger the word size the faster the computer’s processing speed. Memory capacity is also a function of word size where a 64-bit computer can transmit a 64-bit address.

Computer processing

The processor performs almost all of the computation and controls the functioning of the other devices. The most common processors are the Intel and AMD, with various versions such as Intel’s Pentium® and Celeron family and AMD’s Athlon and Duron. Other processors include the Apple Mac’s Motorola 6809E microprocessor.

Remember that a processor’s power is measured by its clock speed in megahertz (MHz) or gigahertz (0Hz), where 1 0Hz = 1000 MHz. These speeds are usually included among the specifications of a computer. Faster clock speeds will produce faster computer processing power, and will be more expensive.

Examples of processor specifications are:

1.0 GHz Pentium 4 or AMD equivalent

Pentium® 4 processor 540 w/HT technology @2.8GHz

Intel Core Duo @ 2.0 GHz.
Memory

RAM is the main memory of a computer; its size is measured in megabytes (Mb) and, as with processors speed, it is better to have more memory. Home computers should have at least 2 gigabytes (Gb: 1024 Mb) of memory but 4 Gb is better since memory speeds can affect performance as well.

The hard drive is a magnetic storage device that holds information when the computer is turned off. Since RAM has processing speeds faster than the hard drive, information is swapped between main memory and the hard drive, The size of a hard drive is measured in gigabytes (Gb) and the larger the hard drive capacity the more data and information can be stored. Access time is measured in milliseconds (ms), for example, 9—28 ms.

Examples of computer systems specifications:
Example

Pentium® 4 processor 540 w/HT technology @2.80GHz

20 inch widescreen flat panel monitor with webcam

USB keyboard and Dell Optical USB mouse

1Gb RAM

DVD/CD-RW drive

Stereo sound card

Monitor: 1024x 768.
FireWire

FireWire is one of the fastest of the peripheral devices developed in recent years that transfer information between digital devices, especially audio and video peripherals such as digital video cameras. FireWire is plug-and-play such that, once connected to a computer, the operating system will automatically detect and install the device. If the device has been previously installed, the computer simply activates it when it is connected.