Monday, October 5, 2009

Input and Output

Magnetic Ink Character Recognition (MICR)

In computing, a technique that enables special characters printed in magnetic ink to be read and input rapidly to a computer. MICR is used extensively in banking because magnetic-ink characters can be machine-read with much greater accuracy than human reading or other optical character recognition (OCR) systems, and are therefore ideal for marking and identifying the account and sort code numbers on cheques.

Optical Character Recognition (OCR)
OCR (optical character recognition) is the recognition of printed or written text characters by a computer. This involves photoscanning of the text character-by-character, analysis of the scanned-in image, and then translation of the character image into character codes, such as ASCII, commonly used in data processing.
In OCR processing, the scanned-in image or bitmap is analyzed for light and dark areas in order to identify each alphabetic letter or numeric digit. When a character is recognized, it is converted into an ASCII code. Special circuit boards and computer chips designed expressly for OCR are used to speed up the recognition process.
OCR is being used by libraries to digitize and preserve their holdings. OCR is also used to process checks and credit card slips and sort the mail. Billions of magazines and letters are sorted every day by OCR machines, considerably speeding up mail delivery.

Optical Mark Recognition (OMR)
Optical Mark Recognition (OMR) is the technology of electronically extracting intended data from marked fields, such as checkboxes and fill-in fields, on printed forms. It is generally distinguished from OCR by the fact that a recognition engine is not required. This requires the image to have high contrast and an easily-recognizable or irrelevant shape. OMR technology scans a printed form and reads predefined positions and records where marks are made on the form. This technology is useful for applications in which large numbers of hand-filled forms need to be processed quickly and with great accuracy, such as surveys, reply cards, questionnaires and ballots.

Dot Matrix Printer
A type of printer that produces characters and illustrations by striking pins against an ink ribbon to print closely spaced dots in the appropriate shape. Dot-matrix printers are relatively expensive and do not produce high-quality output. However, they can print to multi-page forms (that is, carbon copies), something laser and ink-jet printers cannot do.

Plotter
A plotter is a very versatile tool. It is sometimes confused with a printer, but a plotter uses line drawings to form an image instead of using dots. A common type of plotter is one that uses a pen or pencil, usually held by a mechanical “arm,” to draw lines on paper as images are typed. It may be a component that is added to a computer system or it may have its own internal computer. It can be used to create layouts, diagrams, specs, and banners.

Photo Printer
A photo printer is usually an inkjet printer, although it can be a thermal dye printer, which has the ability to print high-quality digital photos and other vibrant color projects. The appeal of being able to print pictures instantly, along with the drop in digital camera prices, has enticed many people to purchase a photo printer. Prior to that, these types of printers were larger, more expensive and generally used only by professionals.

Portable Printer
A portable printer performs the same functions just like any other ordinary printer except its a portable printer is smaller in size compared to the usual printers used in the offices. Some Portable printers use blue tooth while others vary in sizes i.e when some can be fitted in a car dash-board or a small table, others can easily slide inside a pocket or a purse. Companies like HP, Samsung and Dell dominate the world of portable printers.

Fax Machine
Short for facsimile machine, a device that can send or receive pictures and text over a telephone line.A fax machine consists of an optical scanner for digitizing images on paper, a printer for printing incoming fax messages, and a telephone for making the connection.

Multifunctional device
Multifunction Device (MFD), is an office machine which incorporates the functionality of multiple devices in one, so as to have a smaller footprint in a home or small business setting or to provide centralized document management,distribution and production in a large-office setting. Eg printer, Scanner, Photocopier, Fax, Email

Internet Telephones
An Internet phone service uses the Internet, instead of old-fashioned phone lines, to send voice. In most cases, you just plug your current telephone into a small box that your Internet phone company provides to you. The box, in turn, plugs into your broadband connection. Just as with regular telephone service, you pick up the phone to get a dial tone and press numbers on the keypad to call the person you want to talk with. And as with a regular telephone, you can call anybody in the world who has a phone. Alternatively, some services have softphones: your computer becomes your telephone, and you talk via a handset or a headset plugged into USB ports.

Monday, September 28, 2009

System Unit

Expansion Card

Also known as an add-on card, internal card or interface adapter, an expansion card is an electronic board or card added in a desktop computer or other non-portable computer to give that computer a new ability, such as the ability to connect to another computer using a network cable. Below is a list of expansion cards that could be installed in a an available expansion slot.

Network Interface Card
A network interface card is used to connect a computer to an Ethernet network. The card provides an interface to the media. This may be either using an external transceiver or through an internal integrated transceiver mounted on the network interface card PCB. The card usually also contains the protocol control firmware and Ethernet Controller needed to support the Medium Access Control (MAC) data link protocol used by Ethernet.

Cache Memory
Cache memory is random access memory (RAM) that a computer microprocessor can access more quickly than it can access regular RAM. As the microprocessor processes data, it looks first in the cache memory and if it finds the data there (from a previous reading of data), it does not have to do the more time-consuming reading of data from larger memory.

Plug & Play
plug and play is a term used to describe the characteristic of a computer bus, or device specification, which facilitates the discovery of a hardware component in a system, without the need for physical device configuration, or user intervention in resolving resource conflicts.Plug and play refers to both the traditional boot-time assignment of device resources and driver identification, as well as to hotplug systems such as USB and Firewire.
Sockets

Computer sockets use standardized protocols to communicate with the devices that are designed to plug into them. When protocols change, computer sockets are renamed, and manufacturers keep pace by designing products that utilize the newer protocols. Computer sockets in the 1980s were referred to as Integrated Drive Electronics (IDE) slots, followed by Enhanced IDE (EIDE) slots.

Chips

The modern computer chip saw its beginning in the 1950s through two separate researchers who were not working together, but developed similar chips. The first was developed at Texas Instruments by Jack Kilby in 1958, and the second was developed at Fairchild Semiconductor by Robert Noyce in 1958. These first computer chips used relatively few transistors, usually around ten, and were known as small-scale integration chips. As time went on through the century, the amount of transistors that could be attached to the computer chip increased, as did their power, with the development of medium-scale and large-scale integration computer chips. The latter could contain thousands of tiny transistors and led to the first computer microprocessors.
There are several basic classifications of computer chips, including analog, digital and mixed signal varieties. These different classifications of computer chips determine how they transmit signals and handle power. Their size and efficiency are also dependent upon their classification, and the digital computer chip is the smallest, most efficient, most powerful and most widely used, transmitting data signals as a combination of ones and zeros.
Today, large-scale integration chips can actually contain millions of transistors, which is why computers have become smaller and more powerful than ever. Not only this, but computer chips are used in just about every electronic application including home appliances, cell phones, transportation and just about every aspect of modern living. It has been posited that the invention of the computer chip has been one of the most important events in human history. The future of the computer chip will include smaller, faster and even more powerful integrated circuits capable of doing amazing things, even by today’s standards.

Slots

Slots are holes used to plug internal devices (sound/video cards...etc) into your computer. These will be found on the inside of your computer...and the devices you pug into the will have "ports" on them...which will be able to be accessed from the back of the computer like the other ones.

Buslines
The bus lines are the communicating electronic lines that connect different parts of the CPU to various other parts. In addition, the bus lines also link the CPU to different parts on the system board of your computer. The data flows in the form of bits along the bus lines. The bus lines are like multilane pathway which means that the more bus lines are on the system the greater is the rate of transfer of data along the bus, which means that the computer can run efficiently and will perform the operations at a faster rate.
Serial Port
A serial port is a serial communication physical interface through which information transfers in or out one bit at a time.


Parallel Port
A parallel port is a type of interface found on computers (personal and otherwise) for connecting various peripherals. It is also known as a printer port or Centronics port.
Universal Serial Bus
USB (Universal Serial Bus) is a popular hardware interface that allows users to attach secondary hardware devices to their computer in a Plug-and-Play fashion.A single USB port can connect more than one hundred interchangeable devices such as modem, keyboard, mouse, joysticks, scanners, printer, digital cameras, and external storage.
Firewire Port
FireWire is a type of Serial Port which uses the serial bus interface standard for high speed data transfer. e.g connecting camcorders with PC.

Monday, August 17, 2009

The Internet, The Web and Electronic Commerce

HTML;
HTML stands for HyperText Markup Language which is a language used to specify the structure of documents for retrieval across the Internet using browser programs of the web.
It is a system of tags used to make web pages. The tags are put before and after text and images, and tell your visitor's browser how the text should appear on the computer screen.

Javascript;
JavaScript is a scripting language used to enable programmatic access to objects within other applications. It is primarily used in the form of client-side JavaScript for the development of dynamic websites. JavaScript is a dialect of the ECMAScript standard and is characterized as a dynamic, weakly typed, prototype-based language with first-class functions. JavaScript was influenced by many languages and was designed to look like Java, but to be easier for non-programmers to work with.

Applets;
Some applets are able to function as any other normal software application (provided they are hosted by an operating system), but are small in size and perform only a small set of tasks. Examples of applications often classified as applets are all of the Accessories in Microsoft Windows (such as Windows Notepad or Microsoft Paint).

Business-to-Consumer E-Commerce;
Business-to-consumer is an electronic commerce business model in which consumers (individuals) offer products and services to companies and the companies pay them.
This business model is a complete reversal of traditional business model where companies offer goods and services to consumers.

Consumer-to-consumer E-commerce;
Consumer-to-consumer or citizen-to-citizen electronic commerce involves the electronically-facilitated transactions between consumers through some third party. A common example is the online auction, in which a consumer posts an item for sale and other consumers bid to purchase it; the third party generally charges a flat fee or commission. The sites are only intermediaries, just there to match consumers. They do not have to check quality of the products being offered.

Monday, August 3, 2009

Careers in IT

Webmaster;
A webmaster is a website specialist who usually designs, controls and maintains websites. They are required to monitor the traffic on websites and web pages, make sites work faster, repair sites that are slow and do not work properly.

Computer support specialist;
assist people who find a difficulty in using a computer. They help people to get familiar with the software, hardware and other application systems that might not be working properly.
Computer specialists work in computer companies, schools, internet cafes and other institutions that involve a certain networks of computers. They assist clients through the phone, face-to-face or through the email.

Technical Writer;
A technical writer is a professional writer who designs, writes, creates, maintains, and updates technical documentation—including online help, user guides, white papers, design specifications, system manuals, and other documents. Engineers, scientists, and other professionals may also produce technical writing, sometimes handing their work to a professional technical writer for editing and formatting. A technical writer produces technical documentation for technical, business, and consumer audiences.


Software engineer;
Software engineers are like webmasters or specialists except these guys work as a team that design new hardware, software and systems.
Software engineers first analyze users' needs. Then they design, construct, test, and maintain the needed software or systems. In programming, or coding, they tell a computer, line by line, how to function. They also solve any problems that arise. They must possess strong coding skills, but are more likely to develop algorithms and solve problems than write code.

Network Administrator;
A network administrator is a person who is incharge in the overall maintainance and control of a network of computers. He is the highest level of networking staff and does not necessarily get involved directly with the system. A network engineer is employed to fix and maintain the routing and functioning of the computer network.

Database Administrator;
Database administrator is a person who stores, organises and manages data in a company. He maintains databases that store information about customers, staff, projects or data from the internet and the electronic commerce. Its crucial for a database administrator to secure all te data that he stores.

System analyst;
System analysts figure out how to use computers to get things done. They tell businesses and other organizations which computers and software to buy, and they decide how to get those tools to work together.

Programmer;

Computer programmers write, test, and maintain the detailed instructions, called programs, that computers follow to perform their functions. Programmers also conceive, design, and test logical structures for solving problems by computer. With the help of other computer specialists, they figure out which instructions to use to make computers do specific tasks. Many technical innovations in programming advanced computing technologies and sophisticated new languages and programming tools, for example have redefined the role of a programmer and elevated much of the programming work done today.