Recap of Lecture 02 v Generations of Computer

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Recap of Lecture 02 v Generations of Computer v Types of Computers v Classifications

Recap of Lecture 02 v Generations of Computer v Types of Computers v Classifications of Computers

INTRODUCTION TO Computer Lecture No 3 Computer Hardware Manual & Automatic Input Devices Output

INTRODUCTION TO Computer Lecture No 3 Computer Hardware Manual & Automatic Input Devices Output Devices

Computer Hardware v Hardware the electronic and mechanical components of a computer systems. v

Computer Hardware v Hardware the electronic and mechanical components of a computer systems. v Physical components and which can be touched, handle or seen physically. v Despite the difference in performance among the different kinds of computers, every digital computer is made up of four basic units, v Input Unit (Input Devices are used to enter data into the Computer) v Out Put Unit (Out Devices are used to see the result of Processed Data ) v Central Processing Unit (CPU) v Secondary Storage

Organization of Computer. Auxiliary Storage Input Units Main Memory & CPU (Central Processing Unit)

Organization of Computer. Auxiliary Storage Input Units Main Memory & CPU (Central Processing Unit) Output Units

Input Unit The initial unit which provides communications between the user and the computer

Input Unit The initial unit which provides communications between the user and the computer is the input unit. This unit describes a device used to transfer information into a computing system. The devices used to give data or commands to computer are called Input devices.

Input & Output Devices

Input & Output Devices

Input Devices Data or information can be fed into computer by using different peripherals

Input Devices Data or information can be fed into computer by using different peripherals i. e. types of input devices. Two types of input devices ◦ Manual Input Devices ◦ Automatic Input Devices

Manual Input Devices § A manual input device requires a human hand to control

Manual Input Devices § A manual input device requires a human hand to control it… Keyboard Mouse Camera Scanner

Manual Input Devices § A manual input device requires a human hand to control

Manual Input Devices § A manual input device requires a human hand to control it… Tracker ball Joystick

Manual Input Devices Device Keyboard Uses Advantages Disadvantages The most common input device People

Manual Input Devices Device Keyboard Uses Advantages Disadvantages The most common input device People are familiar with keyboards, so they don’t need to be trained Many people cannot type and look at the screen at the same time, so typing can be time consuming You press keys to input data into the computer The most common type of keyboard is the QWERTY keyboard Skilled typists can work very quickly They are very reliable and cheap

Manual Input Devices Device Mouse Uses Advantages Most common pointing device Combines well with

Manual Input Devices Device Mouse Uses Advantages Most common pointing device Combines well with a keyboard Used to point and click on icons or menus Fast and accurate A tracker ball is basically an Tracker ball upside down ball mouse. The user runs their thumb over the ball to control the onscreen pointer Useful where desk space is limited Disadvantages Need a flat surface to use them Some people find that the thumb gets painful with prolonged use Ball can get greasy and dirty

Manual Input Devices Device Joystick Uses Originally designed for pilots to control aeroplanes Used

Manual Input Devices Device Joystick Uses Originally designed for pilots to control aeroplanes Used to control wheelchairs and for playing games Scanner Used to convert printed images or text into a file of digital data Advantages They give a more realistic gaming experience when playing games such as flight simulators Disadvantages Some people find them difficult to operate. Many different types available Images can be edited before use The quality of the final image is dependent on the original image

Manual Input Devices Device Digital Camera Uses Used for taking still images which can

Manual Input Devices Device Digital Camera Uses Used for taking still images which can be uploaded to a computer for permanent storage Advantages Disadvantages You can preview the image before pressing the shutter button No film needed or development costs When the drive is full, images need to be uploaded to a computer or deleted Unwanted images can be deleted Touchpad or Fingerpad A pointing device, built into a laptop for convenience Portable - built into the laptop Small movements needed to move the cursor Takes practice to master

Automatic Input Devices § An automatic input device inputs data without the need for

Automatic Input Devices § An automatic input device inputs data without the need for human intervention (once the device has been set up), e. g. MICR, OMR, barcode reader, webcam, microphone. Microphone Barcode reader Webcam

Automatic Input Devices Device Uses Banks print important data on the bottom of cheques

Automatic Input Devices Device Uses Banks print important data on the bottom of cheques using magnetic ink MICR Magnetic Ink Character Recognition This ink is then read by a computer Advantages Disadvantages Very quick and accurate processing of data – very low error rate. Expensive to produce and print magnetic ink, and the reader is also expensive Very secure as any attempt to change the numbers on a cheque will be ignored as the reader only recognises magnetic ink in the same font Banks are the main user – very few other applications

Automatic Input Devices Device Uses Advantages Used to mark Very fast method multiple choice

Automatic Input Devices Device Uses Advantages Used to mark Very fast method multiple choice examof reading data, Optical papers, National which save time. Mark Testing Service Recognition (NTS) use OMR for More accurate than human paper checking. data entry OMR Disadvantages Sometimes incomplete marks are not read correctly

Automatic Input Devices Device Barcode Readers Uses Advantages Used to identify products in shops

Automatic Input Devices Device Barcode Readers Uses Advantages Used to identify products in shops Disadvantages Very quick and accurate way to The code is read by enter data – suits busy shops a barcode scanner which identifies the Prices changes are product name, made on the product size/weight database, not the manufacturer name barcode All barcodes need to be programme into the compute in advance

Automatic Input Devices Device Uses Used to input Microphone sound into the computer Used

Automatic Input Devices Device Uses Used to input Microphone sound into the computer Used to give the computer commands, or to dictate letters directly to a word processor Webcam Used to input moving images into the computer for use in online communication Advantages Very cheap piece of equipment Helpful for people with additional needs or for busy people who need very quick letters Very cheap piece of equipment Disadvantages Computer can misread voice instructions due to natural variations in people’s voices The moving picture tends to flicker due to Enables people to current limitations see each other in data transfer

Output Devices

Output Devices

Output Devices § An output device is used to display or use information that

Output Devices § An output device is used to display or use information that comes out of a computer system. § Output devices convert electrical signals from a computer system into… ü Sound (speakers or headphones) ü Images , video & Text (screen or printer)

Output Devices Monitor Speakers Printer Headphones Plotter

Output Devices Monitor Speakers Printer Headphones Plotter

Output Devices Device Uses Advantages Disadvantages Take up very little Easy to damage TFT

Output Devices Device Uses Advantages Disadvantages Take up very little Easy to damage TFT Monitor. Thin Film Transistor space monitors are more commonly known as flat screens or LCD screens Run very quietly and produce little heat Colour contrast on cheaper models is not as good as CRT monitors Use about a third of the energy of a CRT monitor CRT Monitor Cathode Ray Tube is very old technology. Almost completely replaced by flat screen monitors Reliable Large Last for a very long time Can be heavy Produce a lot of heat Old technology

Output Devices Device Uses When connected to a computer through a sound card, music

Output Devices Device Uses When connected to a computer through a sound card, music can be played Speakers & Headphones Gives feedback to user during general computer use Plotter These are specialist printers that can produce high quality printouts on large pieces of paper Advantages Disadvantages Games are a lot more involving and realistic with sound Speakers are not useful in a network room, as everyone would disturb each other Headphones can be uncomfortable with extended use Very high quality printouts Slower than normal printers Almost any size Expensive paper can be used

Printers There are 3 main types of printer… Device Inkjet Laser Dot Matrix Uses

Printers There are 3 main types of printer… Device Inkjet Laser Dot Matrix Uses Advantages Disadvantages General purpose Cheap to buy use for family or Latest models home office can be very fast Ink cartridges can be very expensive Business use for Quality printing letters, Good for large stationery and areas of colour images Quiet & Quick More expensive to buy than inkjets Business use for duplicate documents Can make a carbon copy Can print on continuous rolls of paper Toner cartridges are expensive Noisy and rather oldfashioned technology Poor quality and only prints in black ink

Soft copy The result (text/graphics ) appear on displayed screen are known as soft

Soft copy The result (text/graphics ) appear on displayed screen are known as soft copy and will disappear if display is switched off. Therefore this form of output is not permanent and can be removed, changed or corrected. Output devices used for soft copy: Visual display unit (monitor or TV screen)

Hard copy The results (text/graphics) printed on paper is known as Hard Copy. It

Hard copy The results (text/graphics) printed on paper is known as Hard Copy. It is considered as permanent copy and can be retained even computer is turned off. Output devices used for Hard copy: ◦ Printer ◦ Plotters

Summary v Introduction to Computer Hardware v Input Unit , Out Put Devices. v

Summary v Introduction to Computer Hardware v Input Unit , Out Put Devices. v Different Types of Manual & Automatic Input Devices v Out Put Devices v Soft Copy v Hard Copy