Give 1 advantage of computerising a system a vector device Name a raster device A screen has a...
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Transcript of Give 1 advantage of computerising a system a vector device Name a raster device A screen has a...
Give 1 advantage of computerising a system
Computers are more consistent and reliable than humans
Computers can process and store vast amounts of data very fast
Computers deal with data
A defrag utility rids our system of viruses
Computers are better suited than humans at jobs requiring creativity
MS Windows is a GUI
CLI is less user-friendly
The Internet gives an infrastructure for the WWW
Computers deal with data (T)
A defrag utility rids our system of viruses (F)
Computers are better suited than humans at jobs requiring creativity (F)
MS Windows is a GUI (T)
CLI is less user-friendly than GUI (T)
The Internet gives an infrastructure for the WWW (T)
People with visual impairment
Braille Keyboard
CAD
Graphics tablet
Correcting multiple choice exam papers
OMR
Processing Bank cheques
MICR
Name a vector device
Name a raster device
A screen has a resolution of 1024 x 768. How many pixels
does the screen have in all?
If the screen uses 8-bit representation. What is its colour depth?
How many bits are needed to draw this screen once?
What do you understand by ‘refresh rate’?
Name a vector device Plotter
Name a raster device Screen, Inkjet Printer, Laser Printer, Dot Matrix Printer
A screen has a resolution of 1024 x 768. How many pixels does the
screen have in all? 1024 x 768
If the screen uses 8-bit representation. What is its colour depth? 28 = 256
How many bits are needed to draw this screen once? 1024 x 768 x 8
What do you understand by ‘refresh rate’? The number of times the screen is drawn per second
A double-sided disk has 10 tracks, each having 12 sectors. A sector can contain 100 bytes. ◦ How many sectors are there on the disk,
assuming it is double sided?
◦ How many records each 30bytes can fit in a sector? (whole records only)
◦ How much wasted space would there be on the disk?
◦ How many sectors are there on the disk, assuming it is double sided?
◦ 10 x 12 = 120 sectors
◦ How many records each 30bytes can fit in a sector? (whole records only)
◦ 100/3 = 3 records
◦ How much wasted space would there be on the disk?
◦ 100 – (30 x 3) = 10 bytes wasted per sector
◦ 120 x 10 = 1200 total bytes wasted
Application software used to locate and display web pages
Application software used to create and edit documents
Application software used for handling and displaying statistical information and datasheets
Application software used to locate and display web pages – Web Browser
Application software used to create and edit documents - Wordprocessor
Application software used for handling and displaying statistical information and datasheets - Spreadsheet
1 magnetic storage device
1 electronic storage device
1 volatile storage device
1 storage device which only allows serial access
1 magnetic storage device
Floppy disk, hard disk, magnetic tape
1 electronic storage device
RAM, ROM
1 volatile storage device
RAM, Cache Memory
1 storage device which only allows serial access
Magnetic Tape
MIPS – Millions of Instructions per Second
DPI – Dots Per Inch
OMR – Optical Mark Reader
CPU – Central Processing Unit
MB - Megabyte
Suggest a record structure for the Student File
Field Name Field type
Student ID Autonumber
Name Text
Surname Text
etc
Dot matrix printer – printing of bills
Laser printer – printing of documents in a
networked office
Ink jet printer – printing of user documents in
a home
Plotter – printing of maps
Graphics tablet - CAD
OMR – correction of multiple choice exams
MICR – processing of bank cheques
OCR – digitising of business papers (eg in an insurance agency)
Barcode reader – bill production at a POS
Image scanner – digitising images for online publication
a. Holds a single data item of a
specified type
b. Is a collection of data items
referring to a particular object
c. Uniquely identifies a record
d. A collection of organised data
structured in such a way that
link between the data allows
for easy access to the data
1. Record
2. Database
3. Keyfield
4. Field
a. Holds a single data item of a
specified type
b. Is a collection of data items
referring to a particular object
c. Uniquely identifies a record
d. A collection of organised data
structured in such a way that
links between the data allow
for easy access to the data
1. Record
2. Database
3. Keyfield
4. Field
1. Raster Device
2. CD-R
3. Vector Device
4. Floppy Disk
5. Hardcopy
6. Softcopy
a. Tangible
b. Pen Plotter
c. 1.44MB
d. Temporary, not tangible
e. Dot matrix printer
f. 650MB
1. Raster Device
2. CD-R
3. Vector Device
4. Floppy Disk
5. Hardcopy
6. Softcopy
a. Tangible
b. Pen Plotter
c. 1.44MB
d. Temporary, not tangible
e. Dot matrix printer
f. 650MB
3 algorithm constructs
Sequence – a number of instructions executed in
succession
Decision – a branching instruction
Loop – a number of instructions that are executed
repeatedly usually until a certain condition is met.
3 ways of representing an algorithm
Flowchart, pseudocode, structure diagram
Textual method of representing algorithms
Diagrammatic method of representing algorithms
Area of memory used to hold data temporarily in order to copy items between applications or locations
Textual method of representing algorithms
flowchart
Diagrammatic method of representing algorithms
Pseudocode
Area of memory used to hold data temporarily in order to copy items between applications or locations
Clipboard
1. Decision
2. Terminator
3. Input/output
4. Process
5. connector
Process Input
output
Terminator
Decision
A small hardware item that is capable of decision making
Gives the expected output for all possible combinations of inputs of a logic gate or logic circuit
An inverter gate
A number system that acts as a shorthand way of representing binary numbers
A small hardware item that is capable of decision making – Logic Gate
Gives the expected output for all possible combinations of inputs of a logic gate or logic circuit – truth table
An inverter gate – not gate
A number system that acts as a shorthand way of representing binary numbers - Hexadecimal