Edexcel GCSE Computer Science (1CP2) Exam Questions

• A Embedded system (1)
• The only correct answer is A. The correct answer is embedded system.
• B is not correct because a general purpose computer can run many different application programs
• C is not correct because a networked computer is connected to other computers to share resources
• D is not correct because a server computer provides services or resources to other computers on a network

Award up to two marks for a linked description such as:

• Data is stored on (flash) memory chips/cells (1) as a pattern of electrical charges (1)
• A current/voltage forces electrons through a barrier (1) so that they are trapped (or not trapped) to hold/represent a value (1)
• Cells with a trapped charge and cells with no trapped charge (1) represent 1s and 0s/binary (1)
• The trapped charge remains when the power is turned off (1) so the data is not lost/it is non-volatile (1)

Do not accept responses that describe magnetic storage, e.g. magnetised platters, spinning disks or read/write heads, or optical storage, e.g. lasers, pits and lands.

Do not award a mark for 'it is solid state' or 'it has no moving parts' without a description of how the data is stored.

Do not award a mark for restating the stem, e.g. 'a laptop uses an SSD' or 'an SSD uses flash memory'.

'Data is stored as electrical charges' on its own, with no reference to memory chips/cells or to how the charge is held, earns a maximum of one mark (1).

A response that only describes electrons being trapped, with no link to how the value/data is represented, earns one mark (1). The second mark needs a link such as trapped and not trapped charge representing 1s and 0s, or the trapped charge being kept so the data is not lost.

Award up to two marks for a linked explanation such as:

• The battery lasts longer/needs charging less often (1) because embedded systems have low power consumption/use less power (1)
• It can be made small/light enough to wear on the wrist (1) because the processor, memory and input/output are combined on a single chip/microcontroller (1)
• It can carry out the step-counting function reliably (1) because it runs a single/dedicated program and cannot install other software (1)
• It has a low cost per unit (1) because it uses fewer/less powerful components than a general purpose computer (1)

For both marks, the expansion must follow/associate with the statement.

Award one mark for a valid point stated on its own, e.g. 'it is small/light enough to wear on the wrist' (1) or 'its battery lasts longer before it needs charging' (1).

Accept the same linked ideas in either order, e.g. 'it uses less power (1) so the battery lasts longer (1)'.

Do not accept 'it uses less power'/'low power' on its own as a complete explanation; it must be linked to the battery lasting longer/needing charging less often for the second mark.

Do not accept an expansion that simply restates the point, e.g. 'it is small (1) so it fits on the wrist' earns only the point mark; 'fits on the wrist' is not a linked cause and is not enough for the second mark.

Do not accept 'the battery is small' as the linked reason for low power consumption.

Do not accept responses that say other software/apps can be installed on an embedded system (0); embedded systems have a single/dedicated function and cannot install new software.

Award up to two marks for a linked explanation such as:

• Decodes/interprets/translates the instruction (1) to work out what the instruction is/what operation is required (1)
• Sends control signals to the other components (1) so that the correct component carries out the instruction (1), e.g. the ALU/main memory
• Controls the fetch of the instruction from main memory (1) because the address of the next instruction is sent via the address bus (1)
• Controls the fetch of the next instruction from main memory (1) by sending a control signal/read signal to main memory (1)

For both marks, the expansion must follow/associate with the statement.

For the decode point, 'decodes the instruction' alone gains 1 mark; a second mark needs the purpose of decoding, i.e. working out what the instruction is/what operation is required.

Do not accept 'it controls the CPU' on its own, without naming a task in the cycle.

Do not accept 'it fetches the instruction from memory' on its own, as this describes the fetch step rather than the control unit's role; credit only if linked to controlling/signalling the fetch.

Do not accept carrying out arithmetic/logical operations, as these are carried out by the ALU, or holding the address of the next instruction, as this is the program counter.

Do not accept storing the instruction in a register (e.g. MAR/MDR), as this is not the role of the control unit.