Past Paper Thursday 13th June 2013 - Afternoon Flashcards
State how many bytes are in a kilobyte? (1)
1 Kilobyte = 1024 bytes.
State how many kilobytes are in a gigabyte? (1)
1 gigabyte = 1024 kilobytes.
Describe the purpose of the ROM in a computer? (2)
- Stores the boot program which is used to start the computer and load the operating system.
Describe the purpose of the RAM in a computer? (2)
- Stores the parts of the OS programs that are running.
- Stores the data which is currently in use for access by the CPU.
State one difference between ROM and RAM, other than the size and the purpose? (1)
- ROM is non-volatile and RAM is volatile.
A game console and a desktop computer are two different types of computer system. Describe how a game console is similar to a desktop computer, with reference to input, output and storage. (6)
Points may include: • Game console has input devices, usually specialised controllers but also keyboards, microphones etc similar to desktop computer • Output is similar to desktop computer on a screen and speakers (sometimes using the same standards eg HDMI, DVI) • Game console usually has an optical drive so that the software to be run can be inserted. Many also have a hard disk drive which is the same as that used on a desktop computer.
State the purpose of an input device in a computer system. (1)
To enter data from outside the system for processing.
State the purpose of an output device in a computer system. (1)
To return the results of processing
Describe two ways that the hardware in the computer terminal can be adapted so that blind customers can use it. (4)
Braille keyboard/input device
• As this is a familiar entry method for blind users
• Braille print out of transaction
• so that customer can review it.
• Use loudspeakers
• To provide audio feedback of actions taken (but not when entering card
details).
Explain why the technicians prefer to use hexidecimal. (2)
- it is 4 bits per hex digit / straightforward to convert
• shorter number to remember/quicker to enter/less susceptible to error.
Display the most appropriate data type for each of these. (4)
- Song
- Length
- TimesPlayed
- Protected
- Song - String
- Length - Real
- TimesPlayed - Interger
- Protected - Boolean
The mp3 player can be connected to a computer from which songs can be added. The computer has a relational database with many tables. Explain, using an example, what is meant by an entity and how entities relate to the tables. (4)
An entity is a type of real world object (about which data is to be stored)
• e.g. Songs/albums/singers etc
• In the relational database each entity is modelled as a table
• Instances/examples/individuals of an entity are represented by
records/rows of the table
• Entities can have attributes
• .. valid example of attributes e.g. length of song
• Attributes of an entity are represented by fields/columns of the table
This is a computer program that simulates a 100m race. Each time the space bar is pressed the position of the player moves up by 1. When the position reaches 100, then the player has one.
CONST PlayerKey = " " Position = 0 REPEAT INPUT KeyPressed If KeyPressed = PlayerKey THEN Position = Position + 1 END If UNTIL Position = 100
State an example of a constant and variable in the algorithm above? (2)
- Constant = PlayerKey
- Variable = Position or KeyPressed
CONST PlayerKey = " " Position = 0 REPEAT INPUT KeyPressed If KeyPressed = PlayerKey THEN Position = Position + 1 END If UNTIL Position = 100
State what is meant by selection and iteration using examples from the algorithm. (4)
Selection -
• A condition is used to decide whether code should be executed.
Example -
• Position = Position + 1 is only run if the IF condition is met.
Iteration - • Code is executed repeatedly. Example - • The code in the repeat loop will be run several times (until Position = 100).
CONST PlayerKey = " " Position = 0 REPEAT INPUT KeyPressed If KeyPressed = PlayerKey THEN Position = Position + 1 END If UNTIL Position = 100
To make the game more interesting, the rules have been changed. Each time the spacebar is pressed, the postion of the player will now move up by a random number. State two changes that need to be made to include this new rule and justify. (4)
Point
• Position = Position + 1 should be changed
• …so the increment is a random number
Justify
• The random number should be relatively small
• …so the game remains interesting
Point
• The end condition of the loop should be changed to UNTIL Position >
100 / check if position > 100 and if so change to 100
• … as the position may not reach exactly 100 due to the random number.
Justify
• seed/initialise random number generation
• … so that numbers generated appear random