Monday, October 5, 2009

Input and Output

Magnetic Ink Character Recognition (MICR)
- The machine recognition of numeric data printed with magnetically charged ink. It is used on bank checks and deposit slips. MICR readers detect the characters and convert them into digital data. Although optical methods (OCR) became as sophisticated as the early MICR technology, magnetic ink is still used. It serves as a deterrent to fraud, because a photocopied check will not be printed with magnetic ink.

http://www.micrprint.com/images/micr_machine.jpg

Optical-Character Recognition (OCR)
- (Optical Character Recognition) The machine recognition of printed characters. OCR systems can recognize many different OCR fonts, as well as typewriter and computer-printed characters. Advanced OCR systems can recognize hand printing.When a text document is scanned into the computer, it is turned into a bitmap, which is a picture of the text. OCR software analyzes the light and dark areas of the bitmap in order to identify each alphabetic letter and numeric digit. When it recognizes a character, it converts it into ASCII text (see ASCII file). Hand printing is much more difficult to analyze than machine-printed characters. Old, worn and smudged documents are also difficult. Scanning documents and processing them with OCR is sometimes as much an art as it is a science.



Optical-Mark Recognition (OMR)
- Optical Mark Recognition (OMR) is the technology of electronically extracting intended data from marked fields, such as check boxes 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.

http://www.hktdc.com/rsc?profile=productimage&subprofile=large&pid=483057&file=image_1.jpg

Dot Matrix Printer
- A printer that uses hammers and a ribbon to form images out of dots. It is widely used to print multiplex forms and address labels. Also known as a "serial dot matrix printer," the tractor and sprocket mechanism in these devices handles thicker media better than laser and ink jet printers.

Hammers Hit the Ribbon
The dot matrix printer uses one or two columns of dot hammers that are moved across the paper. The hammers hit the ribbon into the paper, which causes the ink to be deposited. The more hammers, the higher the resolution. For example, 9-pin heads produce draft quality text, while 24-pin heads produce typewriter quality output. Speeds range from 200 to 400 cps, which is about 90 to 180 lpm.

http://www.kulimtypewriters.com.my/Printer2/Printer2_files/kxp1121.jpg

Plotters
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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. The plotter was the first computer output device that could print graphics as well as accommodate full-size engineering and architectural drawings. Multicolor plotters use different-colored pens to draw different colors.

In general, plotters are considerably more expensive than printers. They are used in engineering applications where precision is mandatory.


http://www.cadstation.com/cusa/images/3Cads_387.jpg

Photo Printer
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A printer specialized for smaller prints such as 4x6" and 5x7". When first introduced in the mid-1990s, photo printers used dye sublimation for high quality printing because ink jet printing was not quite up to par. Since then, ink jet technology has greatly improved, and most photo printers are ink jets. Epson, Canon and HP are major players in this market.

http://www.digitalworldtokyo.com/entryimages/251105_Canon_Printer.jpg

Portable Printer
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Portable printers are small, lightweight inkjet or thermal printers that allow computer users to print from laptop computers when traveling. They are easy to carry, convenient to use but generally more expensive than normal inkjet printers due to the compact design. Their printing speed is also lower than normal printers. Some portable printers are designed to print photos immediately from digital cameras and are known as portable photo printers.

http://images.pcworld.com/reviews/graphics/115857-2206P072_1B.jpg

Fax Machine
- Telecommunications
technology used to transfer copies (facsimiles) of documents, especially using affordable devices operating over the telephone network. The device is also known as a telecopier in certain industries. When sending documents to people at large distances, faxes have a distinct advantage over postal mail in that the delivery is nearly instantaneous, yet its disadvantages in quality have relegated it to a position beneath email as the prevailing form of electronic document transfer except where the legal status of a sent fax and its accompanying sending report are desired.

http://www.cordless-phones.uk.com/img/large/003907.jpg

Multifunctional Devices
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An MFP (Multi Function Product/ Printer/ Peripheral), multifunctional, all-in-one (AIO), or 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 (the SOHO market segment), or to provide centralized document management/distribution/production in a large-office setting. A typical MFP may act as a combination of some or all of the following devices:
  • Printer
  • Scanner
  • Photocopier
  • Fax
  • Email

http://img.tomshardware.com/us/2003/04/07/scanning/aufmacher.jpg

Internet Telephones

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A category of hardware and software that enables people to use the Internet as the transmission medium for telephone calls. For users who have free, or fixed-price Internet access, Internet telephony software essentially provides free telephone calls anywhere in the world. To date, however, Internet telephony does not offer the same quality of telephone service as direct telephone connections.

http://salestores.com/stores/images/images_747/910156222.jpg

Telephony
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Meaning "sound over distance," it refers to electronically transmitting the human voice. In the beginning, telephony dealt only with analog signals in the circuit-switched networks of the telephone companies. It later referred to a mix of analog and digital circuits, but still with the telephone industry. Starting in the 1990s, telephony began to embrace sending voice over IP (VoIP) networks, which is now deployed by common carriers, private enterprises and independent VoIP providers.

http://ntrg.cs.tcd.ie/undergrad/4ba2.05/group8/image3.jpg



Blessings,
* Vanessa *

Monday, September 28, 2009

System Unit

Expansion Card
- An expansion card (also expansion board, adapter card or accessory card) in computing is a printed circuit board that can be inserted into an expansion slot of a computer motherboard to add additional functionality to a computer system. One edge of the expansion card holds the contacts (the edge connector) that fit exactly into the slot. They establish the electrical contact between the electronics (mostly integrated circuits) on the card and on the motherboard.

http://www.asihome.com/images/pa-kxta82481.jpg

Network Interface Card (NIC)

- Stands for "Network Interface Card." Pronounced "nick," this is the card that physically makes the connection between the computer and the network cable. These cards typically use an Ethernet connection and are available in 10, 100, and 1000 Base-T configurations. A 100 Base-T card can transfer data at 100 Mbps. The cards come in ISA and PCI versions and are made by companies like 3Com and LinkSys. So if you want to connect your computer to a network, you better get yourself a NIC.

http://cache.gizmodo.com/assets/resources/2007/08/network_card2.jpg

Plug & Play
- Plug and Play, sometimes, abbreviated PnP, is a catchy phrase used to describe devices that work with a computer system as soon as they are connected. The user does not have to manually install drivers for the device or even tell the computer that a new device has been added. Instead the computer automatically recognizes the device, loads new drivers for the hardware if needed, and begins to work with the newly connected device.

While Plug and Play usually refers to computer peripheral devices, such as keyboards and mice, it can also be used to describe internal hardware. For example, a video card or hard drive may be a Plug and Play device, meaning the computer will recognize it as soon as it is installed. The only difference is that internal components usually require the computer to be turned off when they are installed, while external devices can typically be installed while the computer is running.

http://www.yankodesign.com/images/design_news/2007/06/20/plug_play.jpg

Sockets
- When a computer program needs to connect to a local or wide area network such as the Internet, it uses a software component called a socket. The socket opens the network connection for the program, allowing data to be read and written over the network. It is important to note that these sockets are software, not hardware, like a wall socket. So, yes, you have a much greater chance of being shocked by a wall socket than by a networking socket.

Sockets are a key part of Unix and Windows-based operating systems. They make it easy for software developers to create network-enabled programs. Instead of constructing network connections from scratch for each program they write, developers can just include sockets in their programs. The sockets allow the programs to use the operating system's built-in commands to handle networking functions. Because they are used for a number of different network protocols (i.e. HTTP, FTP, telnet, and e-mail), many sockets can be open at one time.

http://www.techfuels.com/attachments/motherboards-memory/7056d1224763046-motherboard-memory-sockets-details-motherboards-memory-sockets-details.jpg

Chips
- A set of microminiaturized, electronic circuits fabricated on a single piece of semiconducting material. While most chips contain only digital logic functions, some chips are analog only, and some are "mixed mode" analog and digital. Digital chips are designed for use as processors, memory and other logical and information processing functions in computers and countless consumer and industrial products.

Chips are the driving force in this industry. Small ones can hold from a handful to tens of thousands of transistors. They look like tiny chips of aluminum, no more than 1/16" square by 1/30" thick, which is where the term "chip" came from. Large chips, which can be the size of a postage stamp, contain up to hundreds of millions of transistors. It is actually only the top one thousandth of an inch of a chip's surface that holds the circuits. The rest of it is just a substrate. The terms "chip," "silicon chip," "microchip" and "integrated circuit" (IC) are synonymous. Although chips may be formed from semiconducting materials other than silicon, this material is used in the vast majority of chips, and "silicon chip" has become a pervasive term with the general public.

http://blufiles.storage.live.com/y1p0zwNBwPux_fmeYSAcPy0Tkv8uYUJuJUgUqJVIGdevNelF0X9wwVSvgcBzrZ_PVzY

Slots
- An opening in a computer where a circuit board can be inserted to add new capabilities to the computer. Nearly all personal computers except portables contain expansion slots for adding more memory, graphics capabilities, and support for special devices. The boards inserted into the expansion slots are called expansion boards, expansion cards , cards, add-ins, and add-ons.

Expansion slots for PCs come in two basic sizes: half- and full-size. Half-size slots are also called 8-bit slots because they can transfer 8 bits at a time. Full-size slots are sometimes called 16-bit slots. In addition, modern PCs include PCI slots for expansion boards that connect directly to the PCI bus.

http://www.brielcomputers.com/slot.jpg

Buslines
- The bus in a PC is the common pathway between the CPU and peripheral devices. Parallel buses use slots on the motherboard and provide multiple lines for data (32 bits, 64 bits) between the CPU and peripheral card. Cards plug into the bus inside the cabinet. Serial buses have external ports, and the cable that plugs into them can connect to multiple devices.

http://img.tfd.com/cde/NORTBRID.GIF

Serial Port
- A socket on a computer used to connect a modem, data acquisition terminal or other device via a serial interface (one data bit following the other). Serial ports provide very slow speeds and have been superseded by USB and other faster interfaces for peripheral connections to desktop computers. Although still widely used in data acquisition, the serial port is no longer found on new computers. Earlier PCs used the port for the mouse, and earlier Macintoshes used it to attach a printer.

http://techpubs.sgi.com/library/dynaweb_docs/linux/SGI_EndUser/books/SGIconsole_HW_CG/sgi_html/figures/connect.O300.serial.port.gif

Parallel Port
- This interface is found on the back of older PCs and is used for connecting external devices such as printers or a scanners. It uses a 25-pin connector (DB-25) and is rather large compared to most new interfaces. The parallel port is sometimes called a Centronics interface, since Centronics was the company that designed the original parallel port standard. It is sometimes also referred to as a printer port because the printer is the device most commonly attached to the parallel port. The latest parallel port standard, which supports the same connectors as the Centronics interface, is called the Enhanced Parallel Port (EPP). This standard supports bi-directional communication and can transfer data up to ten times faster than the original Centronics port. However, since the parallel port is a rather dated technology, don't be surprised to see USB or Firewire interfaces completely replace parallel ports in the future.

http://www.onlinecomputertips.com/images/parallel.jpg

Universal Serial Bus (USB)
- Abbreviated USB, it is a standard type of connection for many different kinds of devices. Generally, it refers to the types of cables, ports and connectors used to connect these many types of external devices to computers.

The Universal Serial Bus standard is a popular one. USB ports and cables are used to connect devices such as printers, scanners, flash drives, external hard drives and more to a computer. In fact, USB has become so popular, it's even used in nontraditional computer-like devices such as video game consoles, wireless phones and more.

http://www.novopc.com/wp-content/uploads/2008/10/usb.jpg

Firewire Port
- This high-speed interface has become a hot new standard for connecting peripherals (no pun intended). Created by Apple Computer in the mid-1990's, Firewire can be used to connect devices such as digital video cameras, hard drives, audio interfaces, and MP3 players, such as the Apple iPod, to your computer. A standard Firewire connection can transfer data at 400 Mbps, which is roughly 30 times faster than USB 1.1. This blazing speed allows for quick transfers of large video files, which is great for video-editing professionals. If 400 Mbps is still not fast enough, Apple Computer released new PowerMacs with Firewire 800 ports in early 2003. These ports support data transfer rates of 800 Mbps -- twice the speed of the original Firewire standard.

You may see Firewire referred to by its technical name, IEEE 1394, since it was standardized by the Institute of Electrical and Electronics Engineers. Both terms refer to the same technology. If your computer doesn't have Firewire and you wish it did, fear not. As long as your computer has PCI slots, you can purchase a PCI Firewire card to add Firewire ports to your computer.

http://www.vivolive.com/img/firewire.jpg



Blessings,
* Vanessa *

Monday, August 3, 2009

Careers in I.T.

Webmaster
Basically, a webmaster is the person responsible for creating, managing and maintaining websites for companies and individuals on the World Wide Web. A webmaster do not just write computer codes or checking and updating web pages, they can be the ones designing the website pages or layouts as well. The webmasters is ultimately responsible for ensuring that a website is easy to navigate and that it addresses the needs of the clients and its customers. All in all, the webmaster must perform a variety of technical tasks to make sure that a website works properly and can be accessed quickly by as many people as possible.

Computer Support Specialist
Computer support specialists help people with computer problems. They provide technical assistance, support, and advice to customers and other users. Some computer support specialists are called help-desk technicians. To make or answer phone calls and e-mails for people who are having difficulty with a particular piece of computer hardware or software. In other words, computer support specialist are the "troubleshooters".
Technical Writer
A technical writer is often tasked with writing documentation that explains technical issues in ways that non-technical people can understand. A technical writer might be responsible for writing the how-to manual for a software application. Technical writers are often copy writers and vice-versa. A good technical writer can write about a complicated technical subject or task in ways that almost anyone can clearly understand. At the same time, precision in technical writing tends to be critical because if anything is described incorrectly, readers may act improperly on what is said, causing mistakes and problems at work.

Software Engineer
Software Engineering is intended to mean the best-practice processes used to create and/or maintain software, whether for groups or individuals, in attempt to rid ourselves of the usual haphazard methods that have plagued the software industry. This would include subjects like Configuration Management, Project Planning, Project Tracking, Software Quality Assurance, Risk Management, Formal Inspections, etc.

Network Administrator
A network administrator oversees computer networks to ensure that they function smoothly where he or she usually configures and manages an existing network. A network administrator installs the necessary hardware and software to set up a computer network, and customizes it to meet the needs of the company using it.

Database Administrator
A database administrator (DBA) is similar to a database developer or designer except that the DBA's key responsibilities is ensuring that a database is available at all to the users and programs that need it. This includes making backups and archiving data. It also includes on-going monitoring to ensure that the database is responding to requests quickly. Sometimes the DBA has some hardware knowledge so that the appropriate servers can be purchased so that the database's performance is not impacted by hardware bottlenecks.

System Analyst
Computer systems analysts analyze business or scientific tasks and plan and develop the hardware systems and software that allow a computer to complete these tasks. These analysts, sometimes called systems analysts, may also work on improving computer systems already in use. They are employed by a wide variety of organizations, including businesses, universities, hospitals, and government agencies. Consulting firms that contract to develop new computer systems also employ systems analysts.

Programmer
Computer programmers write the step-by-step instructions that direct computers to process information. These instructions, or programs, tell the computer what to do in a series of logical steps. Programmers work on a wide range of projects. The kind of work a programmer does depends on the employer. Programmers work in manufacturing, industry, engineering, government offices, hospitals, and educational institutions. Programmers receive detailed job descriptions that identify the goal of the program. Programmers then may prepare systems flow charts that show diagrammatically how information will flow through the computer and its peripheral, or related, equipment. If much creativity and expertise are demanded at this step, systems analysts or computer software engineers may prepare the systems flow charts. In most medium to large computer installations, programmers receive their instructions from systems analysts or computer software engineers.