Thursday, January 15, 2009

Computer hardware

Typical PC hardware

A typical personal computer consists of a case or chassis in a tower shape (desktop) and the following parts:

Internals of typical personal computer.
Inside a custom computer.


  • Motherboard - It is the "body" or mainframe of the computer, through which all other components interface.
  • Central processing unit (CPU) - Performs most of the calculations which enable a computer to function, sometimes referred to as the "backbone or brain" of the computer.
    • Computer fan - Used to lower the temperature of the computer; a fan is almost always attached to the CPU, and to the back of the case, also known as the 'muffin fan'.
  • Firmware is system specific read only memory.
  • Internal Buses - Connections to various internal components.
  • External Bus Controllers - used to connect to external peripherals, such as printers and input devices. These ports may also be based upon expansion cards, attached to the internal buses.

Power supply

Main article: Computer power supply

A case contro, and (usually) a cooling fan, and supplies power to run the rest of the computer, the most common types of power supplies are mechanic shed (old) but the standard for PCs actually are ATX and Micro ATX.

Video display controller

Main article: Graphics card

Produces the output for the visual display unit. This will either be built into the motherboard or attached in its own separate slot (PCI, PCI-E, PCI-E 2.0, or AGP), in the form of a graphics card.

Removable media devices

Main article: Computer storage
  • CD (compact disc) - the most common type of removable media, inexpensive but has a short life-span.
    • CD-ROM Drive - a device used for reading data from a CD.
    • CD Writer - a device used for both reading and writing data to and from a CD.
  • DVD (digital versatile disc) - a popular type of removable media that is the same dimensions as a CD but stores up to 6 times as much information. It is the most common way of transferring digital video.
    • DVD-ROM Drive - a device used for reading data from a DVD.
    • DVD Writer - a device used for both reading and writing data to and from a DVD.
    • DVD-RAM Drive - a device used for rapid writing and reading of data from a special type of DVD.
  • Blu-ray - a high-density optical disc format for the storage of digital information, including high-definition video.
    • BD-ROM Drive - a device used for reading data from a Blu-ray disc.
    • BD Writer - a device used for both reading and writing data to and from a Blu-ray disc.
  • HD DVD - a high-density optical disc format and successor to the standard DVD. It was a discontinued competitor to the Blu-ray format.
  • Floppy disk - an outdated storage device consisting of a thin disk of a flexible magnetic storage medium. Used today mainly for loading RAID drivers.
  • Zip drive - an outdated medium-capacity removable disk storage system, first introduced by Iomega in 1994.
  • USB flash drive - a flash memory data storage device integrated with a USB interface, typically small, lightweight, removable, and rewritable.
  • Tape drive - a device that reads and writes data on a magnetic tape, used for long term storage.

Internal storage

Hardware that keeps data inside the computer for later use and remains persistent even when the computer has no power.

  • Hard disk - for medium-term storage of data.
  • Solid-state drive - a device similar to hard disk, but containing no moving parts and stores data in a digital format.
  • RAID array controller - a device to manage several hard disks, to achieve performance or reliability improvement in what is called a RAID array.

Sound card

Main article: Sound card

Enables the computer to output sound to audio devices, as well as accept input from a microphone. Most modern computers have sound cards built-in to the motherboard, though it is common for a user to install a separate sound card as an upgrade. Most sound cards, either built-in or added, have surround sound capabilities.


Main article: Computer networks

Connects the computer to the Internet and/or other computers.

  • Modem - for dial-up connections or sending digital faxes. (outdated)
  • Network card - for DSL/Cable internet, and/or connecting to other computers, using the Ethernet cord.
  • Direct Cable Connection - Use of a null modem, connecting two computers together using their serial ports or a Laplink Cable, connecting two computers together with their parallel ports.

Other peripherals

Main article: Peripheral

In addition, hardware devices can include external components of a computer system. The following are either standard or very common.

Wheel mouse

Includes various input and output devices, usually external to the computer system


Main article: Input
  • Text input devices
    • Keyboard - a device to input text and characters by depressing buttons (referred to as keys), similar to a typewriter. The most common English-language key layout is the QWERTY layout.
  • Pointing devices
    • Mouse - a pointing device that detects two dimensional motion relative to its supporting surface.
    • Optical Mouse - a newer technology that uses lasers, or more commonly LEDs to track the surface under the mouse to determine motion of the mouse, to be translated into mouse movements on the screen.
    • Trackball - a pointing device consisting of an exposed protruding ball housed in a socket that detects rotation about two axes.
  • Gaming devices
    • Joystick - a general control device that consists of a handheld stick that pivots around one end, to detect angles in two or three dimensions.
    • Gamepad - a general handheld game controller that relies on the digits (especially thumbs) to provide input.
    • Game controller - a specific type of controller specialized for certain gaming purposes.
  • Image, Video input devices
    • Image scanner - a device that provides input by analyzing images, printed text, handwriting, or an object.
    • Webcam - a low resolution video camera used to provide visual input that can be easily transferred over the internet.
  • Audio input devices
    • Microphone - an acoustic sensor that provides input by converting sound into electrical signals


Main article: Output
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Tuesday, December 23, 2008

Check the grip of computer security programs in the Secunia PSI

Secunia PSI

With the large number of software programs installed on the computer, sometimes we less concerned about the security of the software. Because we also may not know the program which allows a computer security slit.

One way to overcome this is to update the software used, but this may be caused. How do I convenience?

Secunia, which is one of the websites in the field of security, has been providing free software to help users check the grip of various security that may occur from a variety of software or programs that install on the computer. And November 25, 2008, after traveling through a fairly long time they released the final version of this software, which Secunia PSI (Personal Software Inspector).

Main features of what Secunia PSI?

In General, Secunia PSI function check software (programs) are installed on the computer from the grip of security, the latest version (update), a program that allows security appear slit. Here's more:

  • Scan, scan the program in the computer
  • Insecure Program, which provides information on the program "less safe" and provide information: a link or download the latest program the solution, add / remove programs, online reference, detail and so forth.
  • End of Life, provides information on programs that do not support another vendor by the author. Accompanied by a download link to the latest version or uninstall.
  • Patched, a program that provides information detected, but not known to have updated security (so may not require more attention)
  • Overview, to provide information (an overview) conditions in the computer after the scan.

In addition, Secunia also check the Web browser plugins such as Adobe Flash Player also Adobe Acrobat Reader, Quick Time, and others.

At ZDNet, Secunia PSI included in 10 Essential security tools, and in order No.1 in the category of free software. So try and fit in the collection. This application is only about 521 KB and can run on the platform of Windows 2000, XP, 32/64bit, and 32/64bit Vista. To be able to run (Scan) it is necessary to have an internet connection. So if used offline this software will not be more useful.

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Monday, December 22, 2008

Graphic design

Graphic design

The term graphic design can refer to a number of artistic and professional disciplines which focus on visual communication and presentation. Various methods are used to create and combine symbols, images and/or words to create a visual representation of ideas and messages. A graphic designer may use typography, visual arts and page layout techniques to produce the final result. Graphic design often refers to both the process (designing) by which the communication is created and the products (designs) which are generated.

Common uses of graphic design include magazines, advertisements, product packaging and web design. For example, a product package might include a logo or other artwork, organized text and pure design elements such as shapes and color which unify the piece. Composition is one of the most important features of graphic design especially when using pre-existing materials or diverse elements.

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Electronic learning

Electronic learning

Electronic learning (or e-Learning or eLearning) is a type of Technology supported education/learning (TSL) where the medium of instruction is computer technology. In some instances, no in-person interaction takes place. E-learning is used interchangeably in a wide variety of contexts. In companies, it refers to the strategies that use the company network to deliver training courses to employees. In the USA, it is defined as a planned teaching/learning experience that uses a wide spectrum of technologies, mainly Internet or computer-based, to reach learners. Lately in most Universities, e-learning is used to define a specific mode to attend a course or programmes of study where the students rarely, if ever, attend face-to-face for on-campus access to educational facilities, because they study online.


The worldwide e-learning industry is estimated to be worth over thirty-eight(38) billion euros according to conservative estimates, although in the European Union only about 20% of e-learning products are produced within the common market. Developments in internet and multimedia technologies are the basic enabler of e-learning, with content, technologies and services being identified as the three key sectors of the e-learning industry.

Growth of e-learning

By 2006, nearly 3.5 million students were participating in on-line learning at institutions of higher education in the United States.Many higher education, for-profit institutions, now offer on-line classes. By contrast, only about half of private, non-profit schools offer them. The Sloan report, based on a poll of academic leaders, says that students generally appear to be at least as satisfied with their on-line classes as they are with traditional ones. Private institutions may become more involved with on-line presentations as the cost of instituting such a system decreases. Properly trained staff must also be hired to work with students on-line. These staff members need to understand the content area, and also be highly trained in the use of the computer and Internet. Online education is rapidly increasing, and online doctoral programs have even developed at leading research universities.


As early as 1993, Graziadei, W. D. described an online computer-delivered lecture, tutorial and assessment project using electronic Mail, two VAX Notes conferences and Gopher/Lynx together with several software programs that allowed students and instructor to create a Virtual Instructional Classroom Environment in Science (VICES) in Research, Education, Service & Teaching (REST). In 1997 Graziadei, W.D., et al., published an article entitled "Building Asynchronous and Synchronous Teaching-Learning Environments: Exploring a Course/Classroom Management System Solution". They described a process at the State University of New York (SUNY) of evaluating products and developing an overall strategy for technology-based course development and management in teaching-learning. The product(s) had to be easy to use and maintain, portable, replicable, scalable, and immediately affordable, and they had to have a high probability of success with long-term cost-effectiveness. Today many technologies can be, and are, used in e-Learning,

from blogs to collaborative software, ePortfolios, and virtual classrooms. Most eLearning situations use combinations of these techniques.

Along with the terms learning technology, instructional technology, and Educational Technology, the term is generally used to refer to the use of technology in learning in a much broader sense than the computer-based training or Computer Aided Instruction of the 1980s. It is also broader than the terms Online Learning or Online Education which generally refer to purely web-based learning. In cases where mobile technologies are used, the term M-learning has become more common. E-learning, however, also has implications beyond just the technology and refers to the actual learning that takes place using these systems.

E-learning is naturally suited to distance learning and flexible learning, but can also be used in conjunction with face-to-face teaching, in which case the term Blended learning is commonly used. E-Learning pioneer Bernard Luskin argues that the "E" must be understood to have broad meaning if e-Learning is to be effective. Luskin says that the "e" should be interpreted to mean exciting, energetic, enthusiastic, emotional, extended, excellent, and educational in addition to "electronic" that is a traditional national interpretation. This broader interpretation allows for 21st century applications and brings learning and media psychology into the equation.

In higher education especially, the increasing tendency is to create a Virtual Learning Environment (VLE) (which is sometimes combined with a Management Information System (MIS) to create a Managed Learning Environment) in which all aspects of a course are handled through a consistent user interface standard throughout the institution. A growing number of physical universities, as well as newer online-only colleges, have begun to offer a select set of academic degree and certificate programs via the Internet at a wide range of levels and in a wide range of disciplines. While some programs require students to attend some campus classes or orientations, many are delivered completely online. In addition, several universities offer online student support services, such as online advising and registration, e-counseling, online textbook purchase, student governments and student newspapers.

e-Learning can also refer to educational web sites such as those offering learning scenarios, worksheets and interactive exercises for children. The term is also used extensively in the business sector where it generally refers to cost-effective online training.

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