CIS070 Fundamentalsof Computing

Theory Unit Part 1

What is a computer?

It is an electronic device that:Receives data (input)Processes data (processing)Stores data (output)Produces a result (storage)

It performs only three operations:Arithmetic operations (+ - / * ^ )Logical comparison of values ( = > < ) Storage and retrieval of operations

Classifying Computers - Supercomputer

Largest and ultrafast computers.Used by government agencies, the scientific community, and large corporations with tremendous volumes of data to be processed.Much faster than any other type of computer.Cost can from $1 million to $20 million.

Classifying Computers – Mainframe

Smaller and less powerful than supercomputers, but still large compared to personal computers.Used by larger institutions and government installations.Used for centralized storage, processing, and management of very large amounts of data. Cost hundreds of thousands of dollars.Usually kept in controlled climate.

Classifying Computers – Minicomputer

Larger than personal microcomputers and basically have the same capabilities.

The cost is much higher.

Would use if there are many users connected to them, and large amounts of data needed to be processed.

In recent years, the minicomputer market has declined.

Classifying Computers – Microcomputer

Also called a PC, personal computer or desktop computer.Type of computer used at home or at the office by one person.Priced anywhere from $300-$3,000.

Notebook (laptop) computer has the same capabilities as the desktop; however, much smaller and usually more expensive.

Because of its size, it is portable and can run on power from an electrical outlet or batteries.Often equipped with wireless connection so they can be used away from a desk.

Classifying Computers – Tablet PC

Type of notebook computer that has an LCD screen that the user can write on using a special-purpose pen or stylus.You can also rotate the screen 180 degrees and lay it flat over the keyboard for a more comfortable reading and writing experience

Other Computing Devices - PDA

PDA (personal digital assistant) – also known as a palm-top.

Smaller than a notebook.

Limited capabilities.

Touch-sensitive screen accepts characters drawn with your finger or a special stylus.

Becoming a common tool for business and professional people, as well as students.

Other Computing Devices

Cell phonesCalculatorsDigital camerasDishwashersRefrigeratorsCars and trucksVarious media players

A computer system consists of 4 parts:

Hardware – the tangible, physical equipment that can be seen and touched.

Software – the intangible set of instructions that tells the computer what to do.

Data – facts entered into a computer (text, numbers, sounds, images)

People – users of the computers who enter data and use the output.

Just about all computers, regardless of size, take raw data and change it into information you can use. The process involves input, process, output, and storage.

You input data with some type of input device.The computer processes it to turn it intoinformation.You output the information to some type of output device.You store it for later retrieval.

Input, output, and processing devices grouped together represent a computer system.

INPUT Devices - KeyboardsMost common input device is a keyboard.Provides a set of alphabetic, numeric, punctuation, symbolic, and control keys.

INPUT Devices – Pointing Devices

Mouse – control the pointer on the screen. Use to have a mechanical ball underneath that rolled on a flat surface. Now, most are optical mouse, which operates with a sensing device in place of the ball. Can be wireless.

Trackball - designed as an alternative to the mouse. It is almost an upside-down mouse; it is stationary and contains a movable ball that you rotate using your fingers to move the mouse cursor on the screen.

Joystick - transfers movements you make with the device into movements on your computer screen. It is used to simulate arcade-style play for computer games.

INPUT Devices – Voice Recognition

Voice recognition devices are used to “speak” commands into the computer and to enter text.To use voice recognition, you will need:

Hardware

Software

Voice recognition technology has

enabled disabled persons to

communicate with a computer using only

voice commands.

INPUT Devices – ScannersScanners are devices that can change images into codes for computer input.There are various sizes and types of scanners.Image scanners – convert images into electronic form that can be stored into a computer’s memory. The image can then be manipulated.

Flatbed scanner is the mostcommon in offices.

Hand-held scanners - device ismoved by hand.

INPUT Devices – Scanners (cont’d)

Bar code scanners – reads bar lines that are printed on products.

Magnetic scanners – read encoded information on the back of credit cards.

INPUT Devices – Other

Graphics Tablets – also called a digitizing tablet – is a flat drawing surface on which the user can draw.

Touch Display Screen – displays shapes or text and you use your finger to “point” to the desired object. Very user friendly.

INPUT Devices – Other (cont’d)

Digital Cameras – pictures are stored in the camera’s memory and can be transferred to the computer’s memory.

Video Input – Images captured with a digital camcorder or from a VCR/DVD player and transferred to a computer.

Capture DVD-quality video from any

camcorder, TV or VCR with Dazzle Digital

Video Creator

INPUT Devices – Other (cont’d)

Digital PenData GloveHead Devices

OUTPUT Devices

Output devices display information.Examples of output are printed text, spoken words, music, pictures, or graphics.

OUTPUT Devices - Monitors

Monitors are called video display screens because images are displayed on the screen.Factors that influence the quality of a monitor are:

CRT versus LCD Screen size Resolution Dot pitch

OUTPUT Devices – Monitors

CRT – Today, one of the most commonly used technologies for computer monitors. CRT, or Cathode Ray Tube, is a technology much like what you will find on most TVs. CRT monitors are bulky and very heavy.

Flat Panel / LCD (Liquid Crystal Display) - monitors are similar to what is found on portable computers. LCD monitors overall generally display much sharper of an image, are lighter and more space efficient; however, they are much more of an expensive solution for desktop displays.

OUTPUT Devices – Monitors

Dimensional Size –Monitors are available in 15",17", and 19“ - larger is generally more expensive. The larger the screen, the more amount of viewable space you will be able to work with. Users who plan on using the computer for graphics should use at least a 21" monitor.

Viewable Size - The viewable size of the monitor is a very important consideration and can varies by manufacturer. The viewable size is the size of viewable area and not the complete monitor.  While a monitor may be labeled a 15- or 17-inch unit, the actual image size ("viewable area") may be an inch or two smaller. The "viewable screen area" measurement is the distance from the top left corner to the bottom right corner of the screen.

When considering purchasing a monitor utilizing the CRT technology it is important to consider the following:

DOT PITCHDot Pitch measurement is found on most monitors - defines the amount of space (in millimeters) that separates two adjacent pixels that are the same color. The smaller the Dot Pitch, the sharper the image. The recommended dot pitch be no bigger than 0.25.

RESOLUTIONThe maximum resolution is the amount of pixels that can be displayed horizontally x vertically. Refers to the sharpness of an image.

These sizes can be debated but are the standard and most easily viewed resolutions.

15" – 800 x 600 / 1,024 x 76817" – 1,280 x 1,02419" – 1,280 x 102421" - 1,600 x 1,200

OUTPUT Devices – Printers

Printers are used to produce a paper or hard copy of the processing results.There are several types of printers with tremendous differences:

Speed - Printer speed is measured in pages per minute (ppm). The number of pages a printer can print per minute varies for text and graphics. Graphics print slower than regular text.Print quality - Print quality if measured in dots per inch (dpi). This refers to resolution.Price – The price includes the original cost of the printer as well as what it costs to maintain the printer. A good quality printer can be purchased very inexpensively; a high-output system can cost thousands of dollars. What is the cost of the ink cartridges or toners?

Two basic types of printers:

LaserProduce images using the same technology as copier machines.The image is made with a powder substance called toner.High-quality output and faster.Cost more than inkjet.

InkjetLeast expensive.Produce excellent color printing.Color is sprayed onto the paper in the form of dots.Slower than laser printers.

All-in-one Printers

Combines printer, scanner, copier, and fax capabilities.

OUTPUT DEVICES: Plotters

Plotters are printers that produce high-quality images by physically moving ink pens over the surface of the paper.They can draw complex line art, including text, but do so very slowly because of the mechanical movement of the pens. Great for creating computer-generated maps, charts, and architectural plans.

OUTPUT DEVICES: Other

Speakers – used to listen to computer-generated sound.

LCD projectors – enables a presenter to project the computer’s screen display onto a screen similar to one used with a slide projector.

White board (also call a smart board) - The touch-sensitive display connects to your computer and digital projector to show your computer image. You can then control computer applications directly from the display, write notes in digital ink and save your work to share later.

Storage Devices

If you want to keep a permanent copy of your data, you must store it on some type of storage medium.

Device is capable of retaining data even when electrical power is switched off.

Storage devices are categorized by the method they use to store date.

Storage Devices – Floppy Diskette

Usually called diskettes.Most are 3 ½” in size.They have a storage capacity to hold 1.44 MB or more of data.

A megabyte (MB) is 1,048,576 bytes.A kilobyte (KB) is 1,024 bytes.These measurements are often rounded off so that a kilobyte is defined as 1000 bytes and a megabyte as 1,000 kilobytes.

Storage Devices – Zip Disk/Drive

A Zip disk can hold as much as 70 floppy diskettes.

Holds about 100-750 MB of data.They costs approximately $10-$15 each.Size is 3 inches.

Zip drive houses a zip disk. You must have a zip drive to use a zip disk.

The drive cost approximately $80-$180 each.

Storage Devices – Compact Disc

CD-ROM ( compact disc read only memory) data recorded on them can be read many times, but it cannot be changed.CD-R (Compact Disc-Recordable) – “write-once” technology; you can’t erase or write over it.

10-pack runs approximately $7700MB - 80 minutes

CD-RW (Compact Disc ReWritable) – allows data that have been saved to be erased and rewritten.

10-pack runs approximately $13650-700MB and 74-80 minutes

CD-RW Drive (also called burners)Internal CD-RW drive – approximately $40External CD-RW drive – approximately $79

Storage Devices – DVD (digital versatile

disk) DVDs come in two standards:

DVD+ (plus)DVD+R – recordable one time; read many times ($9-$12)DVD+RW – can be rewritten many times ($18-$21)4.7GB and 120 minutes; 10-pack approx. $9-$11Supported by Philips, Sony, Dell, Ricoh, Hewlett-Packard, Yamaha

DVD– (dash) DVD-R you can write one time; read many times ($9-$12)DVD-RW – can write, erase, and read many times ($18-$21)4.7GB and 120 minutesSupported by Panasonic, Toshiba, Apple, Hitachi, NEC, Pioneer, Samsung, and Sharp

Storage Devices – DVD-RAMEnables computer users to burn DVDs containing up to nearly 5 GB of data.Can be recorded and erased repeatedly but are only compatible with devices manufactured by the companies that support the DVD-RAM format. Can be rewritten 100,000 times (100 times more than either DVD-RW or DVD+RW)Costs approximately $5-$7 each

Storage Devices – JUMP Drive

Also called flash drive, thumb drive, pen driveUSB connection - Memory size from 64 MB-4 GBRange in price from $10 - $100 (depending on memory size)

Storage Devices – Network Drive

A network drive is located on another computer or sever that provides space you can use for storage.It might appear as the Q:\ drive or S:\ drive.

This is a “picture” of the network drives available here on the CCC campus.

Students have access only to the “J” drive. This is where instructors sometimes put files for students.

The “K” and “L” drives are for the faculty and staff here on campus.

Note the icon for a network drive.

Storage Devices Virtual and Internet Storage

Some companies provide internet-based storage (also called remote file storage or virtual hard drive). Internet storage is a simple means of sharing files.It is also used for off-site backups of data.Most sites that offer this service charge a modest fee; and some will provide either a more restricted free service or a limited free trial. Example: Drive HQ - http://www.drivehq.com/

Storage Devices Virtual and Internet Storage (cont’d)

Example: http://www.i2drive.com