9618/11 Paper 1 – October/November 2023

Define each vector graphic term:

Drawing list

Drawing object

Property

• Drawing list → Property data required to create all components in the graphic

• Drawing Object→ A component created using a formula

• Property → Defines one characteristic of a component

Define bit depth in a bitmap image and explain how changing it affects the image.

• Definition: The number of bits used to represent each colour.

• Effect:

  • Increasing bit depth allows more colours, making the image more realistic.

  • Decreasing bit depth reduces colours, making the image less detailed/realistic.

Why is a bitmap image usually compressed before emailing?

• Reduces bandwidth usage and transmission time.

• Reduces file size to meet email attachment limits.

• Saves storage space on email servers.

Describe the function of a router in a network.

• Receives packets from external networks (e.g., the internet).

• Analyses destination IP addresses and forwards packets accordingly.

• Uses routing tables and may perform Network Address Translation (NAT).

State the purpose of each device used to support a network.

• Switch:

• Wireless Access Point (WAP):

• Bridge

• Switch: Connects multiple devices, forwards data to correct destination.

• Wireless Access Point (WAP): Enables devices to connect to a network using Wi-Fi.

• Bridge: Connects two LAN segments using the same protocol.

Identify two drawbacks of storing files on the public cloud.

• Files are inaccessible without a stable internet connection.

• Free storage is limited; more space requires payment.

One advantage of using a star topology over a bus topology.

Less disruption when a cable fails because devices connect directly to a switch, not a single cable, improving fault tolerance.

Give three advantages of relational databases over file-based systems.

1. Reduced data redundancy.

2. Improved data integrity and referential integrity.

3. Allows program-data independence, complex queries, and improved data privacy.

Write SQL to create a database named SHOP.

CREATE DATABASE SHOP;

Identify two special purpose registers used in the CPU and describe their roles.

• Program Counter (PC): Stores the address of the next instruction to be fetched from memory.

• Memory Address Register (MAR): Holds the address of the memory location (or I/O device) currently being accessed.
  (Also valid: CIR – holds current instruction; SR – holds status flags like overflow, etc.)

Describe the role of the Immediate Access Store (IAS) in a computer system. (VIP)

• Volatile Memory

• (Holds) In-use data/insruction/programs

• Prompt (fast) access times

Explain how increasing the clock speed from 2.1 GHz to 4 GHz improves CPU performance.

• CPU performs nearly twice as many F-E cycles per second.

• From 2.1 billion to 4 billion F-E cycles per second.

Explain why a dual-core CPU is not always twice as fast.

• Additional overhead due to core communication.

• Software may not support multi-core → one core idle.

• Memory speed may limit performance.

• Other differences like RAM or GPU may affect speed.

Describe interpreter advantages over a compiler.

• An interpreter translates and executes the program line by line, whereas a compiler translates the entire program at once.

• An interpreter stops when it finds an error, while a compiler reports all errors after the entire program is compiled.

• Errors can be corrected immediately with an interpreter, unlike with a compiler, which requires recompilation after changes.

• The effect of any change can be seen immediately when using an interpreter, whereas with a compiler, changes only show after the program is re-run.

• An interpreter can translate partial programs, while a compiler requires the full program to be correct before it can compile.

Why are some languages compiled and interpreted?

• Platform-independent via interpretation.

• Code optimised for CPU at runtime.

• Faster as no need to recompile.

Identify two presentation features in an IDE.

• Prettyprint

• Auto-indentation / formatting
  (Also accepted: expand/collapse code blocks)

Identify two debugging features in an IDE.

• Single stepping

• Breakpoints
  (Also valid: variable expressions, report window)

Describe principal operations of a 3D printer.

• Additive manufacturing.

• Builds from CAD/digital model.

• Constructs one layer at a time starting from the bottom

• Uses x, y, z coordinates.

Purpose of a temperature sensor in a 3D printer.

• Prevent overheating.

• Detect temperature of object/material.

Two advantages of DRAM over SRAM in a 3D printer.

• Lower cost per unit.

• Higher bit density (stores more per chip).
  (Also valid: fast access not required.)

Purpose of first pass in a two-pass assembler.

To Create symbol table.

Instruction examples from each group.:

• Data movement:

• Arithmetic:

• Conditional:

• Data movement: LDR #50 or STO 201

• Arithmetic: ADD 100 or INC IX

• Conditional: JPE 96

One similarity and one difference between direct and indexed addressing.

• Similarity: Both load contents of address to ACC.

• Difference:

  • Direct: Uses operand as address.

  • Indexed: Adds IX to operand to calculate address.

One other addressing mode besides direct and indexed addressing.

Indirect or Relative

Explain importance of feedback in control systems

• Ensures system stays within criteria.

• Output affects input.

• Conditions adjusted automatically.

Example of an embedded system and why it qualifies

Example: Washing machine.
Explanation:

• It is dedicated to one task: managing washing cycles.

• It is built into a larger system (the appliance).

• It does not need much processing power to perform its functions.

• It contains firmware that isn’t easily updated.

• It has its own processor, memory, and I/O, but does not run a general-purpose OS.