What is computer aided design?

It is the use of software to create, modify and analyse a design, producing an accurate model of a product or structure in place of a hand-drawn plan.

Give two advantages of being able to rotate a model on screen.

The designer can check the appearance and fit from any angle without building anything, and a client can be shown the product realistically before it is made.

What is clash detection in a design package?

The software checks whether any two parts occupy the same space or foul one another when they move, finding errors that would otherwise appear only when the parts were assembled.

WJEC A-Level Computer Science 601-5345-3

Hardware: Architecture, Memory and Storage

Topic overview Components of a computer system and how they connect Von Neumann architecture and the CPU The fetch-execute cycle Memory and caching Parallel processing Input and output devices and their uses Secondary storage, fragmentation and defragmentation

Networks and Data Transmission

Topic overview Serial and parallel transmission Simplex, half duplex and full duplex Multiplexing and switching Packets and the TCP/IP protocol stack Networks, standards and protocols Collisions and shared media Routing, addressing and the internet

Logic Gates and Boolean Algebra

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Data Representation and Data Types

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Data Structures

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Organisation of Data: Files and Records

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Database Systems

Topic overview Flat files and the relational model Relational and other contemporary database systems Primary, foreign, composite and candidate keys Indexes and links between tables Entity relationship modelling Normalisation to third normal form The database management system, queries and user views

The Operating System

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Algorithms and Programs

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Principles of Programming

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Systems Analysis

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Software Engineering and Program Construction

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Types of Software System

Topic overview Off-the-shelf, bespoke and custom software Open source and proprietary software Computers in weather forecasting Computer aided design and manufacture Robotics in industry Computer generated graphics and animation Expert systems

Practical Programming

Topic overview Designing data structures: fields, records and data types Key fields and methods of access Validation of input data Designing routines with pseudocode Tracing code and test data Prototyping and evaluating a solution Annotated listings and readable code

Data Security and Integrity

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Computing, Society and the Law

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Advanced Data Structures and Logic

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Recursion, Sorting and Searching

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Programming Paradigms and Translators

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System Design and Human-Computer Interaction

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Software Engineering Tools and Professional Practice

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Advanced Architecture and Assembly Language

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Communication Networks and File Organisation

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Number Representation and Floating Point

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Databases and Distributed Systems

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Operating System Management

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Software Systems and Applications

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Data Security, Cryptography and Attack

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Types of Software System

Computer aided design and manufacture

3 things to know
AS Unit 1

Overview

Computer aided design, clash detection in a design package and how simulation within a design package reduces cost.

What you need to know

Answer each one before you reveal it.

Your recallNot started

Key term

Distinguish a wireframe model from a solid model.

Key term

Why are libraries of standard components valuable in a design package?

Key term

How are layers used in a design drawing?

Questions from this subtopic

Each one with the model answer underneath.

1
What is computer aided design?
Model answer
It is the use of software to create, modify and analyse a design, producing an accurate model of a product or structure in place of a hand-drawn plan.
2
Distinguish a wireframe model from a solid model.
Model answer
A wireframe records only the edges of an object, so it is quick to display but ambiguous; a solid model records the volume the object occupies, so weight, strength and clashes can be calculated from it.
3
Why are libraries of standard components valuable in a design package?
Model answer
Parts such as bolts, valves and door frames are already drawn to their exact dimensions, so a designer inserts a correct component instead of redrawing it and risking an error.
4
How are layers used in a design drawing?
Model answer
Different aspects such as the structure, the wiring and the plumbing are drawn on separate layers that can be shown or hidden, so one drawing serves several trades without becoming unreadable.
5
Give two advantages of being able to rotate a model on screen.
Model answer
The designer can check the appearance and fit from any angle without building anything, and a client can be shown the product realistically before it is made.
6
What is clash detection in a design package?
Model answer
The software checks whether any two parts occupy the same space or foul one another when they move, finding errors that would otherwise appear only when the parts were assembled.

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Hardware: Architecture, Memory and Storage

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