1. Input to the Computer * Input * Keyboard * Pointing Devices
* Source Data Automation
* Terminals
* Multimedia Input Devices
* Data Accuracy
Input to Computer

2. Components of a Computer System
Second Memory
Input
Device
Output
Device
CPU CU
ALU
Primary Memory
Market Share
Input Processing Output
CPU: Central Processing Unit
ALU: Arithmetic Logic Unit
CU : Control Unit
Overview of Computer Concepts

3. Input
* Input
Input refers to the process of entering data, programs, commands, and user responses into main memory of the computer.
* Types of Input
- Data: raw facts, including numbers, letters, words, images, and sounds.
- Programs: instructions that direct the computer.
- Commands: key words and phrases that the user inputs to direct the computer to perform certain activities.
- User responses: the data that a user inputs to respond to a question or message from the software.
Input to Computer

4. Keyboard * Keyboard is a common input device of computers.
* Traditional Keyboard
similar to a typewriter
* Untraditional Keyboards
- McDonald’s Keyboard
- Chinese character keyboard
* Data Entry Operators
who use computer terminals to enter large amounts of data from source documents.
Input to Computer

5. Pointing Devices (1) * Mouse * Trackball * Joystick
* Pen Input Devices
* Touch Screen
* Light Pen
* Digitizer
* Graphics Tablet
Input to Computer

6. Pointing Devices (2) * Mouse
a computer input devices that actually looks a little bit like a mouse.
* Pointer (Cursor)
a flashing indicator on a screen that shows where the next user-computer interaction will take place.
* Icon
a pictorial symbol on a screen. A computer user can interact with an icon by using a mouse.
Input to Computer

7. Pointing Devices (3) * Trackball
a variation of the mouse. To move the cursor, the user rolls a ball that is embedded in the top of the trackball devices.
* Joystick
A Joystick uses the movement of a vertical stem to direct the pointer.
* Pen Input Devices
Pen input devices allow the user to use the pen to input hand-printed letters and numbers to record information.
* Touch Screen
A touch screen allows users to touch areas of the screen to enter data.
Input to Computer

8. Pointing Devices (4) * Light Pen
A light pen is used to touching it on the display screen to create or modify graphics.
* Digitizer
A digitizer converts points, lines, and curves from a sketch, drawing, or photograph to digital signals and transmits them to a computer.
* Graphics Tablet
A graphics tablet converts points, lines, and curves from a sketch, drawing, or photograph to digital signals and transmits them to a computer. It also contains unique characters and commands that can be automatically generated by the person using the tablet.
Input to Computer

9. Source Data Automation (1)
* Image Scanner
* Optical Recognition
- Optical Mark Recognition (OMR)
- Optical Character Recognition (OCR)
- Handwritten Characters
- Bar Codes
* Magnetic-Ink Character Recognition ( MICR)
* Data Collection Devices
* Voice Input ( Speech Recognition)
Input to Computer

10. Source Data Automation (2)
the use of special equipment
to collect data at the source and
send it directly to the computer.
Input to Computer

11. Image Scanner - Source Data Automation (3)
* What is an image scanner?
An image scanner, also called Page Scanner, is an input device that electronically captures an entire page of text or image such as photographs or art work.
* How does an image scanner work?
The scanner converts the text or image on the original document into digital information that can be stores on a disk and processed by the computer (Image Processing System).
Input to Computer

12. Optical Recognition- Source Data Automation (4)
Optical Mark Recognition (OMR)
* What is Optical Mark Recognition?
Optical Mark Recognition (OMR) uses a light beam to recognize marks on paper.
* What are OMR used for?
OMR devices are often used to process questionnaires or test answer sheets.
Input to Computer

13. Optical Recognition- Source Data Automation (5)
Optical Character Recognition (OCR)
* OCR Device
OCR device uses a light beam to read special characters.
* OCR-A
OCR-A is a common standard font for optical character recognition.
* Wand Reader
Wand Read is a popular input device for reading OCR-A.
Input to Computer

14. Optical Recognition- Source Data Automation (6)
Handwritten Characters
* Handwritten Characters Devices
Handwritten Characters devices can read handwritten characters by optical recognition techniques.
* Legibility of Handwritten Characters
- Make your letters big
- Use simple shapes
- Use block printing
- Connect lines
- Close loops
- Do not link characters
Input to Computer

15. Optical Recognition- Source Data Automation (7)
Bar Code Reader
* Optical Codes
Optical codes use a pattern or symbols to represent data.
* Bar Code (the most common optical code)
A bar code consists of a set of vertical lines and spaces of different widths.
* Bar Code Reader
Bar Code Reader is a stationary photoelectric scanner used to input a bar code, the pattern of vertical marks that represents the Universal Product Code (UPC) that identifies a product.
Input to Computer

16. MICR - Source Data Automation (8)
Magnetic-Ink Character Recognition (MICR)
Magnetic-Ink Character Recognition (MICR) involves
characters made of magnetized particles. The characters are
put on documents (bank checks) by MICR inscribers and are
read by MICR reader/sorters.
Input to Computer

17. Data Collection Devices - Source Data Automation (9)
* Data Collection Devices allow direct, accurate data entry in places.
* Data Collection Devices are designed and used for obtaining data at the site (factories) where the transaction or event being reported takes place.
Input to Computer

18. Voice Input (Speech Recognition)
Voice is the process of presenting input data to the computer through the spoken word
* Speech Recognition Devices
Speech Recognition Devices convert spoken words into a digital code that a computer can understand.
* Digital Signal Processor (DSP)
DSP changes sound into the digital form understood by computer.
* Discrete Word Systems require speakers to pause between words.
* Continuous Word Systems allow a normal rate of speaking.
Input to Computer

19. Terminals
*Terminals
Terminals (display terminals, or video display terminals) consist of a keyboard and a screen.
* Dumb Terminal
Dumb terminal does not process data.
* Smart Terminal
Smart terminal can do some processing, usually to edit data it receives.
* Intelligent Terminals
Intelligent terminals can be programmed to perform a variety of processing functions. Intelligent terminals have built-in processing capabilities and have also secondary storage devices such as disk drives.
Input to Computer

20. Multimedia Input Devices
Multimedia is the combination of sound and image with text and graphics.
* Sound Input
such as Electronic music keyboard
* Voice Input
such as Speech-to-text system
* Digital Camera
Captures digital image
* Video Input
Converts video into digital data
Input to Computer

21. Data Accuracy * GIGO GIGO stands for Garbage In , Garbage Out.
Because inaccurate information caused by inaccurate data is often worse than no information at all.
* Data Tests before Processing
- Tests for data type and format
- Tests for data reasonableness
- Tests for data consistency
- Tests for transcription and transposition errors
Input to Computer