MATSEC Past Papers May 2010 Paper 1 Paper

MATSEC Past Papers May 2010 • • Paper 1 Paper 2 A

10 What is the difference between each of the following pairs of items? Syntax Error �Caused by forgetting certain codes and statement structures �Not obeying the programming language’s rules �The compiler will find these errors Logical Error �A mistake found in the actual design of a program �Use of the wrong mathematical operation �Found by gaining the wrong results Ex. Average = 10+11+2/3

What is the difference between each of the following pairs of items? Byte �A byte is a group of 8 bits Compiler �Compiler translates a high level language source code into Word �A word is a group of bits that are handled as a unit by the instruction set of the CPU Assembler �Assembler translates Assembly language into machine code.

What is the difference between each of the following pairs of items? Integer data type �Can only store whole numbers CAD �computer aided design � 3 D sketches of an object Real data type �Can store numbers with decimal places CAM �computer aided manufacturing �Processes models from CAD and manufactures them using machines

Give one reason why: 4 Passwords are required �To prevent unauthorised access to files and other resources The Data Protection Act as established �To protect sensitive data of the individual and prevent unauthorised distribution and access of data. Backups are made �So that if the original files are corrupted they can be replaced with their backups. Software is copyrighted � it’s the right of the author which states that software cannot be copied or modified

5 Fill in the missing terms; �The ALU performs arithmetic and logical operations �A character code that is widely used in computers is ASCII or UNICODE �Two types of optical storage media are CD and DVD �A computers main memory stores both data and addresses �A parity bit is an extra bit that is added to a byte to help detect errors

1 Which communication medium transfers data as pulses of light? �Fibre 3 optic cables List another 3 types of communication media �Telephone �Cable line �Satellite line

4 Identify Two advantages and two disadvantages of using a wireless network at home Advantages: Computers can be placed anywhere There is no need for cables. Disadvantages: More security risk, Sometimes signal doesn’t reach all places.

2 A computer currently has 512 MB of main memory and the owner wishes to upgrade it to 1 GB. If the memory chips available have a capacity of 256 MB, how many of these chips are needed? � 512 2 / 256 = 2 Mention two advantages of having a larger memory �The computer will be much faster �Multitasking will not slow down the computer

3 Describe a problem for which a computer simulation would be a suitable method of solution and explain why a computer simulation would be the most suitable method in this case �Training an airplane pilot, since an airplane is dangerous to fly without any experience since it can cause a lot of damage, the pilot has to be trained in a safe environment first. (Other simulations: space exploration, soldier training)

4 Briefly describe two methods of validating data and for each method give an example of invalid data �Method 1: Range check, if a month is inputted, it has to be checked if it’s between 1 and 12. �Method 2: Check digit, if a number is inputted (such as credit card number) a special algorithm is carried out and it checks if the

6 Mention 3 types of documentation that are produced during software development and state why each is needed �User: helps the user on how to use the basic functionality of a program. �Technical: helps the technician solve problems using troubleshooting and how to conduct any changes to the program. �Programmer: Helps programmer understand the program through graphical representations such as flowcharts and comments.

2 Write the binary equivalent of the hexadecimal number 4 A 4 A = 10 8 4 2 1 0 1 0 1 0

2 If the ASCII code equivalent to the letter A is 65. Which letter does the binary number 01001010 represent 01001010 = 74 65 66 67 68 69 70 71 72 73 74 A B C D E F G H I J 74 J

2 What is the largest number that can be stored in an 8 -bit register 128 64 32 16 8 4 2 1 1 1 1 128 + 64 + 32 + 16 + 8 + 4 + 2 + 1 = 255

4 Consider the terms below : flash memory, scanner, mouse, modem, RAM Which of the above is a form of volatile storage? � RAM of the above can translate drawings and Which photos into digital format? �Scanner Which of the above allows digital data to be transmitted over telephone lines? �modem Which of the above is a form of non-volatile storage? �Flash memory

Consider the truth table below A B C X Y Z 0 0 0 1 0 0 0 1 1 0 1 0 1 0 1 1 1 0

9 Draw the logic circuit corresponding to the truth table A B X Y C Z

Paper 2 A We will be doing a class correction of paper 2 A together tomorrow so please bring this paper worked out