State the functions of the following registers
Program counter // PC
• Stores the address of the next instruction to be fetched
Memory address register // MAR
• Stores the address where data/instruction is to be read from or saved to
Memory data register // MDR
• Stores data that is about to be written to memory // Stores data that has just been read from memory
Current instruction register // CIR
• Stores the instruction that is currently being decoded/executed
State advantages of star network topology
Give one advantage of a star network when compared to a ring network.
– if one station/cable fails, others are not affected
– easier to identify faults when using star topologies
– it is easier to expand this type of network
– performance doesn’t deteriorate under load
Students are using their wireless notebooks to complete their work in a classroom. They will need to connect wirelessly to a printer to print their answers at the end of the lesson.
Describe how CSMA/CA (Carrier-sense multiple access with collision avoidance) operates in the above scenario.
Give any three advantages of computer networks
Explain the difference between
(i) serial and parallel,
(ii) simplex and duplex
modes of data transmission.
Clearly define a computer
Describe the role of the registers and system clock within the fetch-execute cycle.
Differentiate between logical and physical network topology
Physical topology - the physical arrangement of nodes of a computer network
Examples
Logical topology- the way data flows in a network
Examples
State two reasons for the increased use of computers in offices (2 marks)
State the differences between a hub and a switch
The Acme company stores data for a private scientific research group. It has recently upgraded its storage capacity and needs to dispose of its existing hard drives securely. Outline two methods for the secure disposal of the data on the hard drives.
Acme company needs to ensure that if they are reselling the drives they wipe the drive (this should be done regardless of the destruction of the drive) to the DoD standard.
This would ensure that any software cannot be used to locate files.
Differentiate between modulation and demodulation as used in data communication
Modulation refers to the process of converting a digital signal to analog signal at the transmission end while demodulation is to converting analog signal to digital signal at the receiving end
State the type of software that is needed for logging onto the Internet and finding websites selling goods and services.
logging on
finding websites
Briefly describe three types of database models
What situations are likely to call for the use of Direct Changed Over?
Describe the purpose of the
(i) control unit
(ii) memory unit
(iii) arithmetic logic unit
in a computer.
i) To manage the execution of instructions
By running a clock
To decode instructions
(ii) To store OS
To store those parts of applications programs currently running
To store data currently in use
(iii) Part of the processor where data is processed/manipulated
All I/O must pass through here
Compare the use of a compiler with the use of an interpreter to translate code
Both translate source code written in high level programming languages into machine code.
Compiler: Produces a single executable file that is portable between machines
Interpreter: Source code needs a special environment to run
Compiler: Needs to be compiled for a particular architecture
Interpreter: Can run on any architecture that has the translator/interpreter
Complier: Entire source code file is translated at once
Interpreter: Code is translated line by line
Compiler: Provides error report at the end of the compilation
Interpreter: Errors more obvious in the sequence
Compiler: The program source code is not available (so helps protect IP)
Interpreter: Source code is available
Compiler: Only has to be translated once (affecting the speed of execution)
Interpreter: Has to be translated each time, therefore (affecting the speed of execution)
Compiler: Requires two files to be maintained (one for execution and for editing purposes)
Interpreter: Requires only one file to be maintained
Distinguish between a client-server and a peer-to-peer network