Case Study 5–The keyboard as a collection device for information systems

1 Information Processing and Technology © Cambridge University Press 2001

Case study 5 The keyboard as a collection device forinformation systems

The keyboard is a common device with a similar format to a typewriter. It is used to input data andinstructions into the computer system. When the keys are pressed they send a code to the next stageof the computer system that electronically registers the particular key (or key combination) used. A keyboard collects data following these steps.

1 Each key has a digital codewhich identifies the char-acter to be input.

2 When a key is pressed thespring makes contact withthe wires under the key.

3 When the key is up thewires are not in contactunder the key.

4 When the key is down thewires form a circuit alongwhich an electrical signaltravels.

6 The binary code for the character is then sent to thecentral processing unitwhere it is processedbefore being displayed onthe monitor.

5 The signal travels to a circuit board in thekeyboard which recognisesthe character represented bythe digital signal.

Case Study 5–The keyboard as a collection device for information systems

2 Information Processing and Technology © Cambridge University Press 2001

Keyboards vary in the health risk they pose to participants who use information systems regularly.The standard qwerty keyboard in use today is not efficient and requires the weaker fingers to regis-ter some of the most commonly used letters. This can lead to health problems such as cumulativetrauma disorders.

Answer the following questions

1 List the steps taken by a keyboard in the collection of data up to the point the data is receivedby the CPU.

2 Explain the way in which the keyboard converts data from analog to digital form.

3 Describe the role of each of the following in collecting data via the keyboard:

a the participant

b the key interface

c circuits

d the keyboard circuit board

e the buses

4 Research the reasons why a Qwerty keyboard is an inefficient keyboard.

5 Find the names of at least three alternative keyboards and explain how they are more efficientthan the Qwerty keyboard.

6 Explain the consequences to participants from overuse of keyboards for data collection.

7 Research two alternative methods of collecting text other than a keyboard and explain theadvantages of each method.