Advanced level 2024 CASPA mock computer science 2
Advanced level 2024 CASPA mock computer science 2
A computer system is designed using the basic Von Neumann model.
(i) Describe what is meant by Von Neumann architecture. [2 marks]
(ii) Describe the role of the registers in the Fetch-Decode-Execute cycle. [5 marks]
(iii) The CPU uses pipelining to improve efficiency.
(b) Explain what is meant by the term ‘pipelining’. [2 marks]
(c) Identify one factor that can affect the performance of the computer system and state how it
impacts the performance. [2 marks]
(d) A virtual machine is used to emulate a new computer system.
Describe one benefit and one limitation of using a virtual machine for this purpose. [2 marks]
(e) State one piece of software which must be stored in a computer’s ROM and RAM. Justifying
your answer. [4 marks]
2. (a) (i) Convert the denary number -23.25 to 8-bit two’s complement format. [4 marks]
The floating point number 0011010100 is stored using 6 bits for the mantissa and 4 bits for the
exponent, both in two’s complement. This number is not normalised.
(ii) Give the normalised version of this number, showing your working. [3 marks]
(iii) Convert your answer to part (ii) to denary, showing your working. [3 marks]
(b) The table shows part of the instruction set for a processor. The processor has one general
purpose register, the Accumulator (ACC)
