PRINTERS

~Printer is used to translated information processed by system unit and present the information on paper. Output from printers is described as hard copy.

FEATURES :

Four basic features:

üResolution

• A measurement of clarity of images produced.

• Measured in dpi( dots per inch). Higher the dpi, better the quality images produced.

üColour capability

• Printers contain black ink or colour ink.

• Colour is used more selectively of report containing graphics and photographs.

üSpeed

• Measured in number of pages printed per minute.

•Single-colour (black) output, 15 to 19 per minute. 13  to 15 pages per minute for colour output.

üMemory

•Used to store printing instructions and documents waiting to be printed.

• The more memory, the faster to create large documents.

It have 4 types of printers :

(1) INK-JET PRINTERS :

-- Although inkjets were available in the 1980s, it was only in the 1990s that prices dropped enough to bring the technology to the high street.
-- A type of printer that works by spraying ionized ink at a sheet of paper.
-- Producing high quality print approaching that produced by laser printers.
-- A typical ink-jet printer provides a resolution of 300 dots per inch, although some newer models offer higher resolutions.

-- Most widely used because:

i.Reliable

ii.Quite

iii.Inexpensive

-- Typical ink-jet printers produce 17 to 19 pages  per minute(black). 13 to 15 pages per minute(colour)

-- For more information, please refer to http://www.webopedia.com/TERM/I/ink_jet_printer.html , http://www.pctechguide.com/53Inkjets.htm

      http://www.desktopclass.com/education/computer-it/what-is-non-impact-printer-discuss-its-different-types.html

(2) LASER PRINTERS :

-- A laser printer is a common type of computer printer that rapidly produces high quality

text and graphics on plain paper.

-- In comparison with the laser printer, most inkjet printers and dot-matrix printers simply

take an incoming stream of data and directly imprint it in a slow lurching process.

-- A laser printer is unable to work this way because such a large amount of data needs to

output to the printing device in a rapid, continuous process.

-- The printer cannot stop the mechanism precisely enough to wait until more data arrives,

without creating a visible gap or misalignment of the dots on the printed page.

-- Laser printers use laser light beam to produce excellent letter and graphics quality images.

It is:

i.More expensive than ink-jet printers

ii.Faster

iii.Used in applications requiring high-quality output.

Another Two categories:

Personal laser printers

§Do not support colour

§Less expensive

§Used by many single player

Shared laser printers

§Support colour

§More expensive

§Used by a group of users

  Shared laser printers typically print over 50 pages a minute

-- For more information, please refer to http://en.wikipedia.org/wiki/Laser_printer

http://www.gadgetvenue.com/samsung-ml-1630-sleek-laser-printer-12222730/

(3) THERMAL PRINTERS :

§Uses heat elements to produce images on heat-sensitive paper.

§Widely used with ATMs and gasoline pumps to print receipts.

§Thermal printers print more quietly and usually faster than impact dot matrix printers.

§They are also smaller, lighter and consume less power, making them ideal for portable and retail applications.

§A thermal printer comprises these key components:

(4) OTHER PRINTERS :

 

Dot-matrix Printers

--Form characters and images using a series of small pins on a printer head.

It is:

I.Inexpensive

II.Quite noisy

Used in task where high-quality output is not required.

--Advantage : The ink ribbon also does not easily dry out, including both the ribbon stored in

the casing as well as the portion that is stretched in front of the print head; this unique
property allows the dot-matrix printer to be used in environments where printer duty can be
rare, for instance, as with a Fire Alarm Control Panel's output.
--For more information, please refer to http://en.wikipedia.org/wiki/Dot_matrix_printer

                                                     http://www.jestineyong.com/?p=2711

Plotters

--Used to produce a wide range of specialized output.

--Plotters used to create:

I.Maps

II.Images

III.Architectural

IV.Engineering drawings

--For more information, please refer to http://en.wikipedia.org/wiki/Plotter  
 
http://www.supplierlist.com/products/category/1003/100328/p-30/Machinery_for_Paper_Wood_and_Furniture.htm
  As my opinion, i think we as a student are more prefer to use laser printer. It is because it is
more easier and convinient are use in printing. This printer have white and black colour, also
have variety of colour. The price are cheaper than other kinds of printer.

Citations:
- http://www.webopedia.com/TERM/I/ink_jet_printer.html , http://www.pctechguide.com/53Inkjets.htm
- http://en.wikipedia.org/wiki/Laser_printer

- http://en.wikipedia.org/wiki/Thermal_printer

- http://en.wikipedia.org/wiki/Dot_matrix_printer

- http://en.wikipedia.org/wiki/Plotter  
-  http://www.sony.com.my/productcategory/di-dpp-photo-printer
-  http://www.smallportableprinter.com/

Photo Printers

§Special-purpose printers designed to print photo-quality images from digital cameras.

§Print 3x5’ or 4x6’ images on glossy, photo-quality paper.
§For more information, please refer to http://www.sony.com.my/productcategory/di-dpp-photo-printer

                                                      http://dutechs.com/products.html

Portable Printers

§Small and lightweight printers( designed to work with notebook computers)

§It may be ink-jet or laser printers

§Print in black and white or colour

§Connect with USB or parallel port connections

§Reduce the power and the features, while raising the price on the product.

§For more information, please refer to http://www.smallportableprinter.com/

                         http://www.coolest-gadgets.com/20080414/canon-pixma-ip100-portable-printer/

• Thermal head — generates heat; prints on paper
• Platen — a rubber roller that feeds paper
• Spring — applies pressure to the thermal head, causing it to contact the thermo-sensitive paper
• Controller boards — for controlling the mechanism

--For more information, please refer to http://en.wikipedia.org/wiki/Thermal_printer

                                                                 http://ean128.co.uk/

CHAPTER 8 = SECONDARY STORAGE

SECONDARY STORAGE 

•        Secondary storage devices are used to save, to back up, and even to transport files consisting of data or programs from one location or computer to another. 

•        Secondary storage devices have always been an indispensable element in any computer system.

•         Secondary storage provides permanent or nonvolatile storage.

•       Some important characteristics of secondary storage include:

1.     Media are actual physical material that holds the data and program.

2.     Capacity measure how much a particular storage medium can hold.

3.     Storage devices are hardware that reads data and programs from storage media.

4.     Access speed measure the amount of time required by the storage device to retrieve data and program. 

 

HARD DISKS

• A hard disk drive (HDD) is a non-volatile , random access device for digital data. It features rotating rigid platters on a motor-driven spindle within a protective enclosure. Data is magnetically read from and written to the platter by read/write heads that float on a film of air above the platters. 

• Introduced by IBM in 1956, hard disk drives have fallen in cost and physical size over the years while dramatically increasing in capacity. Hard disk drives have been the dominant device for secondary storage of data in general purpose computer since the early 1960s. They have maintained this position because advances in their areal recording density have kept pace with the requirements for secondary storage. Today's HDDs operate on high-speed serial interfaces; i.e., serial ATA (SATA) or serial attached SCSI  (SAS).           

Components  

• A typical hard disk drive has two electric motors; a disk motor to spin the disks and an actuator (motor) to position the read/write head assembly across the spinning disks.

• The disk motor has an external rotor attached to the disks; the stator windings are fixed in place.   

• For more information refers to http://en.wikipedia.org/wiki/Hard_disk_drive     

INTERNAL HARD DISK   

• It is located inside the system units. 
• The are designated as C drive. 
• Are able to storage and retrieve large quantities of information quickly. 
• Used to storage program and large data files.                                                
    
   
  http://www.blogger.com/goog_227295440
  
  
  EXTERNAL HARD DRIVE     
  • Provide fast access, they have a fixed amount of storage and cannot be easily removed from the system cabinet. 
  • Typically connect to a USB or FireWire port on the system unit, are easily removed and effectively provide an unlimited amount of storage. 
  • For desktop computers have typically capacities of 20 to 500 GB. 
  •   Credit card-size hard disks cartridges called PC Card hard disks are available for notebook computers with typically capacities up to 5 GB.

 

http://www.build-your-own-computer.net/external-hard-drive.html

Secondary storage are important because can be used to restore a backup of your files if you have to format. It also can be bring it with you if you need to access files at work or somewhere else. Without secondary storage you would lose all of you data every time your computer powered down. In order words , your computer would not have anywhere to save data indefinitely. For more information you can refers to http://wiki.answers.com/Q/Why_secondary_storage_devices_are _important.                                                                                                                            

Citation ~ http://wiki.answers.com/Q?Why_secondary_storage_devices_are_important.       

~http://en.wikipedia_org/wiki/Hard_disk_drive                                       

~Computing Essentials 2010 Books                                                        

CHAPTER 7 : INPUT & OUTPUT

Image Chapturing Devices

Reference Information from Computing Essentials Complete 2010 :

• Optical scanners is tradisional copy mechines, make a copy from an original.
• Exp : digital copy of a photograph
• Image Capturing Device can create & capture original images.
• Exp : digital cameras, digital video cameras
• Captured image data and the time spatial parameter corresponding thereto to be stored in the storage server @ recorded on the recording medium.
• Captured image data and the time spatial parameter corresponding thereto are supplied to the image data processing unit in the holographic stereogram producing device.
• Time spatial parameter is used as a second time spatial parameter which is required at the time of producing a holographic stereogram.
• For more information you can search in http://www.freepatentsonline.com/7256783.html

(1) Digital Camera

• Images are recorded digitally on a disk @ camera's memory and then downloaded @ tranferred to computer.
• View it immediately.
• a camera that takes video or still photographs, or both, digitally by recording images via an electronic image sensor.
• Digital camera can do things film cameras cannot: displaying images on a screen immediately after they are recorded, storing thousands of images on a single small memory device, and deleting images to free storage space.
• Digital cameras are incorporated into many devices ranging from PDAs and mobile phones (called camera phones) to vehicles.
• For more information you can search in http://en.wikipedia.org/wiki/Digital_camera

http://gadgetophilia.com/c/digital-camera/page/4/

 http://www.conita.com/Digital-Cameras/Nikon-Digital-Cameras/

(2) Digital Video Camera

• Record motion digitally on a disk @ camera's memory.
• WebCams : capture images & send to computer for broadcast over the internet. It is designed to be attached to the computer monitor.
• Connected with the computer network via USB port or sometimes with ethernet and wi-fi.
• Its usages are seen in video telephony, recording of video files and still-images which one can access through many software applications and devices.
• Webcam has made possible for internet users to see famous TV , which was quite popular across the globe.
• Webcam is good source for deaf and speech-impaired individuals.
• For more information you can search in http://hubpages.com/hub/Webcam-means-video-capturing-device
  
  
                        http://www.willshops.com/samoon-hd-dv200-high-definition-digital-video-camera-dvc-p-1458.html
  
  
  
  
  
  
  
  http://www.techshout.com/gadgets/2006/24/g-shot-dv815z-a-feature-rich-multi-functional-5-in-1-digital-video-camera-unveiled-by-genius-in-india/
  
  
  
  
  
  Summary :
  Nowaday many people use the digital camera to capture their beautiful picture. Image capturing device is a easy material to use it and it is a convinient to give us to bring it to anywhere, such as go traveling. Image capturing devise is a moden camera, it is have more advantage than the old ones, film camera. 

Citations : - http://www.freepatentsonline.com/7256783.html
                 - http://en.wikipedia.org/wiki/Digital_camera
                 - http://hubpages.com/hub/Webcam-means-video-capturing-device



CHAPTER 5 SYSTEM SOFTWARE

System Software

> Works with end users, application software, and computer hardware to handle the majority of technical details.

> consists of 4 types of programs :

Operating system -  coordinate computer resources, provide an Interface between users and the computer, and run programs.

Utilities - perform specific tasks related to managing computer resources.

Device Drivers - allow particular input or output devices to communicate with the rest of the computer system.

Language Translator - convert programming instructions written by programmers into a language that computers can understand and process.

OPERATING SYSTEM

> The nucleus of all software activity.

> The operating system is the most important program that runs on a computer. Every general-purpose computer must have an operating system to run other programs. Operating systems perform basic tasks, such as

• recognizing input from the keyboard
• sending output to the display screen
• keeping track of files and directories on the disk
• controlling peripheral devices such as disk drives and printers.

                                   

[Operating System] [Image]. (n.d.). Retrieved from http://depts.alverno.edu/cil/mod1/software/system.html

> Function

  - Providing a graphical user interface (GUI) and running applications such as multitasking allows switching between different applications stored in memory. 
  - Managing computer's resources including memory, processing,storage, and devices. They also monitor system performance, schedule tasks, provide security and startup computer.


> Features
  -  Booting starts (cold boots) or restarts (warm boots) a computer system. The desktop provides access to computer resources. Common features include icons, pointers, windows, menus, dialog boxes, and Help. Data programs are stored in a system of files and folders.

> Categories

  - Embedded operating system are used for handheld devices such as smart Phone, PDA. The entire operating system is stored within or embedded in the devices includes ROM (read-only-memory) located on network server.

  - Network operating system are used to control and coordinate networked computer. It only connect a limited number of microcomputers.

> Stand-alone operating system usually called as desktop operating system, control a single desktop or laptop located on local hard disk.

Different Types of Operating System

Window

 - The most widely used operating system, is designed to run with Intel and Intel-compatible microprocessors. There are numerous versions of window. Window 7 is the most recent versions of Window. It provides improved handwriting recognition, taskbar with previews, large icons, and personalization features, and advanced search capabilities.

Mac OS

 - An innovative, powerful, easy to use operating system, runs on Macintosh computers. Recent versions provide Spotlight, an advanced search tool, and Dashboard Widgets, a collection of specialized programs. Some versions of MAC OS X come with Boot Camp, which allows Macintosh computers to run both MAC OS and Window OS.

UNIX and LINUX

 - Under UNIX, the Operating System consists of many programs along with the master control 

   program, the kernel.      

   The kernel provides services to start and stop programs, handles the file system, etc.

 - The original name was UNICS which stands for UNiplexed Information and Computing Services. 

 - UNICS was later renamed to UNIX (UNIX is not an acronym).

 - UNIX was attractive to other organizations and universities for a few reasons [3]:

• It was the only powerful interactive system that could run on the sort of hardware that universities could afford in the mid ’70s.
• It was written in an attractive language, C.
• When UNIX got into the hands of many teachers and students and individuals around the world, it got further improved and became popular since.

EXAMPLE :

  The computer the first UNIX version was created in, model: DEC PDP-7

  Manufacturer: Digital Equipment Corporation
  Year: 1965
  Price: $72,000 USD
  Power: less than a typical cellphone of today

[UNIX] [Image]. (n.d.). Retrieved from 
http://www.unixnewbie.org/what-is-unix-and-linux/

Linux is a UNIX clone. It was created at the University of Helsinki in Finland by a student named Linus Torvalds in 1991.

The Linux operating system is developed under the GNU General Public License (also known as GNU GPL) and its source code is freely available to everyone.

Linus Torvalds

[LINUX] [Image]. (n.d.). Retrieved from 
http://www.unixnewbie.org/what-is-unix-and-linux/

Utilities

 - Utility software is a kind of system software designed to help analyze, configure, optimize and maintain the computer.

 - Utility software should be contrasted with application software, which allows users to do things like creating text documents, playing games, listening to music or surfing the web. Rather than providing these kinds of user-oriented or output-oriented functionality, utility software usually focuses on how the computer infrastructure (including the computer hardware, operating system, application software and data storage) operates.

 - The most essentials are troubleshooting, antivirus, uninstall, backup, restore, and file compressions.

Device Drivers

 - Allow communications between hardware devices. Add a Device Wizard gives step by step guidance to install printer devices drivers. Window update automates the process of updating the devices drivers versions.


*** Information is getting from the book - Computing Essential 2011