This document provides information on tools for information processes, focusing on transmitting and receiving data, and displaying data. It discusses key concepts such as parallel vs serial transmission, synchronous vs asynchronous transmission, hardware such as modems and networks, software such as communication programs and protocols, and social and ethical issues regarding data transmission and display. Parallel transmission sends data simultaneously along multiple channels but only works over short distances, while serial transmission sends data bits one after another along a single channel but can work over longer distances. Communication concepts like direction of data flow and transmission speed are also defined.

1. ZARKOVIC
TOOLS, Part 4
Tools for Information Processes

2.  In this lesson we will concentrate on the
final two information processes:
– Transmitting and receiving data
– Displaying data

3. Transmitting and receiving
data
 This is an important area of study as it
forms the basis of the Year 12 core unit
Communications
 It is highly theoretical and involves the
explanation of a lot of technical terms

4. Communication Concepts
 There are a few basic concepts in the
syllabus that need to be carefully defined
and explained to students

5. Parallel vs Serial data
transmission
 Parallel – the data bits are transmitted simultaneously along multiple
(‘parallel’) channels
– Used extensively inside the computer system e.g. data bus, address bus, etc
– Quick
– Can only be used over short distances(<1m) as the signals begin to decay or
channels get out of sync
 Serial – the data bits are transmitted one after the other (in single file)
along a single channel
– Slower than parallel
– Good for long distances e.g. networking

6. Parallel vs Serial data transmission
Parallel Serial
Transmission Transmission
0 0 1 0 0 1 0 1
0 0 0 0 0 0 0 0
To CPU ….
To server…

7. Direction of data flow
 Can be classified as simplex, half duplex, full
duplex
 Simplex – data flows in one direction only e.g.
Free to air television
 Half Duplex – data can flow in both directions, but
not simultaneously e.g. Walkie Talkie
 Full Duplex - data can flow simultaneously in
both directions e.g. telephone

8. Synchronous vs
Asynchronous
 Refers to the method used to transmit serial data
 Asynchronous – Each byte of data is sent one at a time
– It is encapsulated within a ‘packet’ of 10 to 12 bits which may
have 1 or 2 start bits and stop bits
– A parity bit is included to aid in error checking (if used)
– Most common method used outside of the computer
 Synchronous – A collection of data is stored as a single
unit called a frame
– The complete frame of data (1024 bytes or more) is transmitted to
the computer
– Faster, more efficient than asynchronous but expensive
– Mostly restricted to use on large computer systems

9. Asynchronous Communication
Parity bit
Start bit
(used for error
checking) 11110111010
A single character of
Stop bit data
Every character of data is transmitted with the start bit,
stop bit and parity bit

10. Synchronous Communication
Groups of characters are transmitted for processing by a
mainframe computer
Individual
Characters
11000001110111010110110000001110
Frame of data
The client and the server computer must synchronise their internal
system clocks. When this occurs the data fame is sent as a block
to the server for processing.

11. Speed of transmission
 Speed of transmission is given as bits per second (bps) or
baud
 A speed of 56000 bps means 56000 bits of data is
transmitted per second
 Baud refers to the number of electrical signals used to
transmit data i.e. timing intervals per second
 More than one data bit may be able to be transmitted per
time interval
 Therefore, a transmission speed of 56000 baud would, in
most circumstances, be considered faster than a speed of
56000 bps

12. Hardware
 Busses – these are the links used within the computer to transmit data from
one part of the computer to the other
 The most important ones are the
– Data bus
– Address bus
 The data bus is the set of parallel links used to move data between RAM
and the CPU = the ‘wider’ the bus the faster data is moved
 The address bus is used to send data request signals to the various memory
locations in RAM
 The ‘width’ of the address bus is important because it determines the
number of addressable memory locations (ie memory size)
e.g. 16 bit address bus => 216 = 65536 (=64kb) addressable memory locations

13. Hardware
 There is also a control bus which is used to transmit
control signals to various computer components
 As well, there are expansion buses, which enable
peripheral devices to talk to the CPU, once the correct
expansion card has been installed

14. Hardware
 Students need to know the general operational principles of a modem
 Since the standard telephone system still uses analogue signals to transmit a
lot of its data, signals from the computer must be converted from digital to
analogue
 This is done by the modem
 The term MODEM is derived from MOdulate / DEModulate
 MODulation occurs when a digital signal is converted into an analogue
signal
 DEModulation occurs when an analogue signal is converted into a digital
signal
 Modems can be internal (built into the system) or external
 Modern modems have additional capabilities e.g. used to send faxes

15. Hardware
 Networks are also a major part of the Year 12 topic
Communications but it only has to touched on lightly here
 Students need to know the difference between a Wide Area
Network (WAN) and a Local Area Network (LAN)
 If you want (and you have time) other network concepts
can also be introduced e.g. ethernet, telecommunications

16. Software
 Basically students need to learn the following
– Types of communications software
 Browsers
 FTP
 Telnet, etc
– The role of protocols in enabling communication to occur
– Electronic mail (although 99% of all students I’ve taught already
know it) e.g. they need to be clear about what CC: and BCC: mean
and how to add an attachment to an e-mail
– Compression software (like WinZip) and what it does
– Encryption of data – why is this necessary?

17. Social & ethical
A lot of scope in this topic to explore social and ethical issues:
 How do we protect against the transmission of viruses?
 What is netiquette and why is it important?
 What copyright issues relate to using the internet?
 How has work changed since the explosion in
communications technology?

18. Displaying

19. Displaying data….
 Involves the output of data/information to meet
the purpose for which the system was originally
developed
 How data/information is displayed depends on the
context e.g. data from a CAD program can be
displayed on a screen in the engineers office,
however, it can also be displayed using a
computerised lathe in the workshop

20. Display Hardware
 Students need to know the basic operating
principles for a number of output devices e.g.
– Monitor
– Printer
– Speaker
– Plotter
 Power’s book covers this fairly well, although
Ware & Grover’s book does a better job outlining
the operational principles of display hardware

21. Display Hardware
 At many schools the industrial arts faculty will
have a plotter and they are usually quite keen to
demonstrate its use to students
 Students should also be shown:
 the operation of a data projector
 laser printer v bubble-jet
 CRT v LCD v plasma screens
 Investigate newer display technologies
e.g. interactive whiteboards, virtual reality, touch
sensitive screens, etc

22. Display Software
 All application software displays data in
some way
 An application may be able to display data
in more than one way
e.g. In the Access database data can be displayed
as a table, using a form, as a result of a query or
as a report

23. Non-Computer Tools
 E.g. a story board is diagrammatic way of
showing how data files can be linked
together - a very important skill as it is of
particular use when developing multimedia
 E.g. old v new animation techniques (jargon
is still the same though)

24. Social and Ethical Issues
 Inclusivity issues e.g. can computer screens can be
adjusted for visually impaired users?
 Investigate assistive technologies available for the
disabled e.g. are web designers providing suitable
display alternatives for disabled users?
 Offensive and pornographic material on the web.
Should free speech be limited?
 Whatever happened to the ‘paperless office’?

25. end