OCR GCSE Computing May 2012  exam paper can be downloaded here



OCR GCSE Computing May 2012  mark scheme can be downloaded here

1A Answer

More help here - Input/Output devices

1B answer

e.g
Touch screen
… respond to fingers / stylus on specified icons
… for example a software keyboard
… eg converts handwriting to text

Hardware buttons
… a small number around the edge of the tablet
… for most common commands
… eg bring up menu / next / previous / play / pause etc…

Microphone
… captures user’s speech and analyses it to match known patterns for commands
… or speech recognition for typing documents
… can be made to learn new commands / macros

Camera
... used to capture user’s image / for webcam applications
... used to capture user’s movement eg as input to games
... used to capture text for processing by OCR

Accelerometer / tilt sensor
... used to determine the position in which the tablet is held
...to change screen orientation automatically (eg movie image)
... used as in input to games
(1 mark for identifying device and 1 mark for use)

2a answer

Bus

More help here - Bus network

2b answer

Router / Modem / ADSL adapter

More help here - Modems and routers explained

2c answer

e.g.

• Controls access to the network / verify passwords entered on any computer
• Provides files to the other computers on the network
• Installs software on workstations
• Make the printer accessible to the other computers
• Controls the access of computers to the Internet/to each other
• Stores, delivers and sends emails for all users on the network

More help here -  Server

2d answer

• All computers have equal status/no server controlling
• To share data/files/devices between each other

More help here -  Peer to peer

3 answer

1
1
1
1


More help here - Logic gates

4 answer

More help here - More file types

5 answer

System cleanup

• (Searches for and) deletes files/programs which are no longer used
• e.g. deletes temporary files / installation files
• deletes settings / registry values which are no longer used

Automatic update

• Checks on the (software manufacturer's site on the) Internet for newer versions of programs which are installed
• If found it download / installs the software

6a answer

0011 0111
(1 mark per nibble) 

More help here -  Denary to binary

6b answer

37
(1 mark per digit)

More help here -  Denary to hex

7a answer

• Fetches instructions (from memory)
• Fetches data (from memory)
• Decodes instructions
• Executes instructions

More help here -  F-E-D cycle

7b answer

Clock Speed:

• The higher the clock speed the faster the CPU will run
• Represents the number of fetch execute cycles / instructions the CPU can process in a given time

Cache size

• the more cache the CPU has the less time is spent accessing memory / programs run faster…
• cache is faster than memory/ built into the CPU/contains frequently accessed data

(max 2 each)

More help here - Clock speed
More help here - Cache

8a answer

• Username: 2012johnsonm
• year 2012, surname: Johnson, initial m
• As there are no other johnsons (so the answer to the decision will be NO)

8b answer

• The pupil joined in 2010
• The pupil's surname is Ali
• The pupil's initial is M
• There were (at least) 3 other pupils called M. Ali in the same year

9a answer

Database management system

9b answer

Points may include:
Features

• Provides a set of tools for accessing/maintaining the database, eg to define/create tables, run queries or define reports
• The application is independent from the data base itself
• Provides data integrity control (eg integrity checks, validation checks)
• Controls access to data, including security and multiple user access

Why desirable

• These can be set up before hand by expert and used by end user
• Separating application and database means the database can be accessed separately by other means eg a desktop application and web application accessing the same data / other suitable example

Data is protected from corruption eg by multiple access


More help here - What is a DBMS

10a answer

• So that computers can be based on logic circuits.
• … ( each part of the circuit) can be in one of two states
• ... 0 and 1/true or false

More help here - Introducing binary

10b answer

• The instruction consists of an operator/op code
• ... and an operand
• both stored as bit patterns
• (op code) from a given instruction set
• Each op code has a unique bit pattern

More help here - Opcodes explained

11a answer

eg

• In high level code Instructions use words
• In machine code instructions are in binary code
• High-level code is designed to be read by human programmers
• Machine code is to be read/executed by the computer
• High level code can be portable/translated for different machines
• Machine code is specific to a particular machine

(marks in pairs)
More help here - HLL explained

11bi answer

• Translates one line of HL code at a time…
• … and executes it
• … stops when it finds an error
• … can be resumed

11bii answer

Compiler

More help here - Compilers explained

11c answer

Points may include:
Programmers need to understand each other's code

• so need clear commenting / consistent formats eg for variable names
• suitable examples

Programmers need to ensure that their code will work with the code written by others

• agree clear interfaces between modules
• and stick to agreed interfaces/ protocols
• suitable examples

The success of one programmer's work depends on the others

• so a need for professionalism
• suitable examples

12a answer

Sequence
Iteration
Selection

More help here - Sequence etc

12b answer

A number which can contain a fractional part
A whole number

12c answer

EXAMPLE:

INPUT Distance
INPUT Passengers
Extra = Distance – 1
CostofExtra = Extra * 2
Cost = 3 + CostofExtra
IF Passengers > 4 THEN
    Surcharge = Cost / 2
    Cost = Cost + Surcharge
END IF
OUTPUT COST

Award marks for:
Inputs distance and passengers
Calculates distance – 1 (or equivalent)
Calculates previous answer * 2(or equivalent)
Calculates previous answer + 3
Checks if more than 4 passengers…
… and adds 50% correctly
Outputs cost