Edexcel GCSE Computer Science (1CP2) Exam Questions

• A Address bus (1)
• The only correct answer is A. The correct answer is address bus. Do not accept 'address' on its own.
• B is not correct because the control bus carries control signals in both directions between the CPU and other components
• C is not correct because the data bus carries data in both directions between the CPU and main memory
• D is not correct because the system bus is the collection of all three buses

• B 7 (1)
• The only correct answer is B. The correct answer is 7 bits.
• A is not correct because 6 bits give only 64 different characters
• C is not correct because 8 bits are used by extended ASCII to give 256 characters
• D is not correct because 16 bits give 65 536 different characters, which is far more than the 128 in ASCII

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

• Makes a file/files smaller (1) so less storage space is needed on the disk (1)
• Reduces the size of the data (1) so it takes less time to upload/download/transfer the file (1)
• Compresses files/folders into a single file (1) so an attachment is under the size limit for email (1)
• Reduces the size of the files (1) so more of them fit onto a storage device/backup media (1)

Do not accept 'it compresses the files' on its own, as this repeats the question.

Do not accept responses about protecting files from malware/viruses or about deleting files.

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

• Instructions can manipulate/control the hardware/memory/registers directly (1) so the driver can control the specific device it is written for (1)
• The code is written for one specific processor/architecture (1) so it works with the exact hardware it will control (1)
• The programmer controls exactly how memory/registers are used (1) so the code is efficient and needs little memory, which suits a device that has limited memory (1)
• Each instruction maps to one machine code instruction (1) so the driver code is small enough to fit in the memory of the device (1)

Extra detail, such as naming the device the driver controls, is not needed to earn the marks.

Do not accept 'it is closer to machine code' on its own: it must be developed to show how this helps the driver, e.g. it can control the hardware directly.

Do not accept 'it is faster/quicker' with no link to the hardware/device, e.g. the device responds quickly.

Do not accept 'it is easier to learn', 'it is easier to debug' or 'it takes less time to write'.

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

• Devices (can) understand/interpret the data they receive (1) because they follow the same set of rules for communication (1)
• Data is sent in an agreed format/structure (1) so the receiving device can interpret/understand it correctly (1)
• Devices (can) connect/communicate successfully (1) because they agree how the data is transmitted, such as the type of signal used (1)
• Errors (can) be detected/handled (1) because both devices follow the same rules for checking the data (1)

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

Do not accept 'so devices can talk/communicate with each other' or 'so they can understand each other' without saying they follow the same rules/agreed format.

Do not accept an answer that only states protocols are a set of rules, without saying what this allows (e.g. the data can be understood/interpreted).

Do not accept a faster connection/speed as a reason why protocols are needed.

Do not accept naming a protocol (e.g. TCP/IP, HTTP, Wi-Fi) without an explanation of why it is needed.

Do not accept a description of what a protocol does (e.g. 'TCP splits data into packets') without saying why this is needed.

Award one mark for each correct nibble in the correct order:

• 1011 (1)
• 0111 (1)

0 marks if the response is not 8-bit binary.

Ignore a carry shown beyond the eighth bit.

Award one mark for:

• overflow (error) (1)