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J277 1 Paper 1 systems and data assessment practice 2

Part 7 of 7 · J277 Paper 1 · Exam transition

A second independent fifty-mark systems and data assessment with fresh values and contexts.

Students will:

  • explain CPU operation and justify a processor choice
  • identify embedded-system features
  • apply units, number conversions, binary carries and shifts
  • explain character, image and sound representation
  • choose compression for a preview and an editable master copy

Inside: 15 text sections, 6 completion activities, 7 number activities, 12 written answers. 50 marks. Suggested time: 60–75 minutes. 1 diagram.

Includes a teacher guide with sections, timings, misconceptions and repair routes. Objective marks and answers are held for teacher review.

Series: J277 Paper 1 · Exam transition, part 7 of 7.

Shared by Coding PathwayVerified teacher

  • 40 cells
  • About 70 minutes
  • CC BY-SA 4.0
  • Shared 26 Oct 2026

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The whole resource, exactly as a class sees it. Answers and marking are held back.

Paper 1 assessment practice 2: systems architecture and data

Answer all questions. The total mark for this worksheet is 50.

  • Work independently.
  • Do not use a calculator.
  • Show all working for calculations and binary addition.
  • Read each command word carefully.
  • Marks and marking guidance will be released by your teacher.

The questions provide a second assessment of OCR J277 1.1, 1.2.3, 1.2.4 and 1.2.5 using new values and contexts.

Section A: systems architecture

Question 1

Complete the description of CPU components.

Do not use the same term more than once.

[5 marks]

Fill in the blanks5 marks
The Answer 1 carries out arithmetic and logical operations. Results from these operations may be stored in the Answer 2. The Answer 3 sends control signals to coordinate the computer. Frequently used data and instructions can be stored in Answer 4, which can be accessed more quickly than RAM. Small, fast storage locations inside the CPU are called Answer 5.

Question 2

Complete the table by identifying the register that matches each purpose.

[4 marks]

Fill in the blanks4 marks
PurposeRegister
Address of the next instructionAnswer 1
Address being accessed in memoryAnswer 2
Data or instruction being transferredAnswer 3
Result of calculations or data currently being processedAnswer 4

Question 3

(a) Describe what happens during the fetch-execute cycle. [2]

(b) Explain the roles of the Control Unit (CU) and Arithmetic Logic Unit (ALU) during the cycle. [3]

Written answer2 marks

(a) Describe what happens during the fetch-execute cycle.

Students type their answer here.

Written answer3 marks

(b) Explain the roles of the Control Unit and Arithmetic Logic Unit during the fetch-execute cycle.

Students type their answer here.

Question 4

Two processors are being considered for a computer used to export videos.

ProcessorClock speedCoresCache
P3.0 GHz812 MB
Q3.6 GHz424 MB

Recommend processor P or processor Q for the computer.

Justify your recommendation using two characteristics from the table.

[4 marks]

Written answer4 marks

Recommend processor P or Q for exporting videos and justify your choice using two characteristics.

Students type their answer here.

Question 5

A greenhouse contains an automatic irrigation controller. It reads soil sensors and opens water valves when needed.

Give three reasons why this controller can be considered an embedded system.

[3 marks]

Written answer3 marks

Give three reasons why the greenhouse irrigation controller is an embedded system.

Students type their answer here.

Section B: units and number representation

Question 6

A set of 750 files has a mean file size of 4 MB.

(a) Calculate the total storage required in GB, using 1000 MB = 1 GB. Show your working. [2]

(b) State the smallest data unit in each pair. [2]

  1. nibble or byte
  2. terabyte or petabyte
Written answer2 marks

(a) Calculate the total storage for the 750 files in GB. Show your working.

Students type their answer here.

Fill in the blanks2 marks
(b) Smallest data unit in each pair

1. nibble or byte: Answer 1

2. terabyte or petabyte: Answer 2

Question 7

Complete parts (a) to (f).

[6 marks]

Number systems1 mark

(a) State the largest denary value represented by 5 bits.

What is the largest denary number 5 bits can hold?

AnswerNot answered
Fill in the blanks1 mark
(b) Minimum number of bits needed for 100 values: Answer 1
Number systems1 mark

(c) State the denary value of 10110110.

What is 10110110 in denary?

Binary
10110110
DenaryNot answered
Number systems1 mark

(d) Give the 8-bit binary value of 147.

Convert 147 to 8-bit binary.

Binary
Number systems1 mark

(e) Give the 2-digit hexadecimal value of denary 58.

Convert 58 to hexadecimal.

Hexadecimal
Number systems1 mark

(f) State the denary value of hexadecimal A7.

What is A7 in denary?

Hexadecimal
A7
DenaryNot answered

Question 8

(a) Complete the 8-bit binary addition. Show all carries. [2]

  01100110
+ 00011011

(b)(i) State the mathematical effect of shifting an unsigned value two places to the right. [1]

(b)(ii) Give the result when 10110100 is shifted two places to the right. [1]

Number systems2 marks

(a) Complete the 8-bit binary addition and show all carries.

Add these 8-bit binary numbers: 01100110 + 00011011.

Carries
First number
01100110
Second number
00011011
Total
Fill in the blanks1 mark
(b)(i) Mathematical effect: Answer 1
Number systems1 mark

(b)(ii) Apply a logical right shift of two places to 10110100.

Apply a logical shift right of 2 places to 10110100.

Before
10110100
After

Section C: characters, images, sound and compression

Question 9

(a) Define the term pixel. [1]

(b) Identify one item of metadata that could be stored with a bitmap image, other than its resolution. [1]

(c) Give one benefit and one drawback of using Unicode instead of ASCII. [2]

Written answer1 mark

(a) Define the term pixel in a bitmap image.

Students type their answer here.

Written answer1 mark

(b) Identify one item of metadata stored with a bitmap image, other than its resolution.

Students type their answer here.

Written answer2 marks

(c) Give one benefit and one possible drawback of using Unicode instead of ASCII.

Students type their answer here.

Question 10

An uncompressed mono sound recording uses a sample rate of 22,000 Hz and a bit depth of 8 bits. It lasts 40 seconds.

(a) Calculate the estimated file size in KB, using 1000 bytes = 1 KB. Show your working. [2]

(b) The sample rate is reduced to 11,000 Hz. Bit depth and duration stay the same. Describe two impacts this has on the recording and the file. [4]

Written answer2 marks

(a) Calculate the estimated file size of the sound recording in KB. Show your working.

Students type their answer here.

Written answer4 marks

(b) Describe two impacts of halving the sample rate on the recording and its file.

Students type their answer here.

Question 11

The diagram shows two ways of compressing an image file.

Two compression methodsAn 18 MB photograph gives a 3 MB file with method A and an 8 MB file with method B. Decompression of A cannot restore the exact original; B can. Both methods start from the original photograph.Original photograph18 MBMethod A: 3 MBAfter decompression:Exact original cannotbe restoredMethod B: 8 MBAfter decompression:Exact original canbe restored

(a) Identify the type of compression used by method A and method B. [2]

(b) Explain one advantage and one disadvantage of using method A for a web preview of the photograph. The original file will be kept separately. [2]

(c) State one reason why method B would be more suitable for a master copy that must be edited later. [1]

Fill in the blanks2 marks
(a) Method A: Answer 1

Method B: Answer 2
Written answer2 marks

(b) Explain one advantage and one disadvantage of method A for the web preview.

Students type their answer here.

Written answer1 mark

(c) State why method B is suitable for an editable master copy.

Students type their answer here.