Contents

About this Chapter

Key Terms in this Chapter

Hardware and Software Overview

CADD Hardware

• System Unit
• Central Processing Unit (CPU)
• Memory
• Hard Disk, Floppy Disk, CD-ROM
• External Storage Devices
• The Monitor
• Printers and Plotters
• Digitizer, Puck and Mouse

A Typical CADD Network

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CADD Software

• Draw
• Edit
• Data Output
• Data Storage and Management
• System Control
• Special Features

CADD User Interface

• Using the CADD Menus
• Entering Commands in the Command Window
• Using the Tool Buttons
• Using the Dialog Boxes
• Working in the Drawing Window

   
About this Chapter 

• CADD Hardware
• CADD Software
• CADD User Interface

Hardware and Software Overview

• Mainframe
• Minicomputer
• Microcomputers, for example personal computers (PCs)

• System software
• Application program

The following are the main hardware components of CADD:

System unit

Central processing unit

Memory

Hard disk, floppy disk, CD-ROM

External storage devices

Monitor

Printers and plotters

Keyboard

Digitizer, puck and mouse

Note: The above topics are described in detail in CADD PRINTER.

A CADD program contains hundreds of functions that enable you to accomplish specific drawing tasks. A task may involve drawing an object, editing an existing drawing, displaying a view of the drawing, printing or saving it, or controlling any other operation of the computer. The functions contain a number of commands that enable you to specify exactly what you want to do and how you want to do it.

The functions are organized into modules that provide easy access to all the commands. The CADD program is divided into modules such as draw, edit, data output, function control, data storage and management. A program may also have a number of specialized functions such as layers, database and 3D. Let's have a look at the CADD modules:

• Draw
• Edit
• Data output
• System control
• Data storage and management
• Special features

Draw

The draw module provides access to all the drawing functions of CADD. Whenever you need to draw something this group of functions is used. The draw module enables you to draw lines, arcs, circles, ellipses, text, dimensions, symbols, borders and many other drawing components.

Draw is CADD's most frequently used module because all drawing work is accomplished using it.

Edit

The edit module lets you change existing drawing elements and manipulate them in a number of ways. You can move, copy or erase drawing components. You can enlarge or reduce the sizes of diagrams or change the color and line type of drawing components. You can also change the size and style of text and dimensions, as well as edit a dimension to show different units of measurement. A good CADD program is designed to change the appearance of all drawing elements created with CADD.

The edit functions also act as convenient drawing-aid tools. They enable you to join missing corners of lines, trim drawing components along a line, stretch them to fit a new shape, etc. The list of editing capabilities goes on and on. The edit functions make CADD a dynamic drawing tool.
 

Data Output

The data output module enables you to display drawings on the screen and then print them on paper. There are two separate sets of functions that help accomplish this:

* View-display functions
* Print/plot functions

The view-display functions allow you to display different views of a drawing on the screen. These functions are used quite often, because every time you need to draw something or edit something, you need to focus on that portion of the drawing. With the help of view-display functions, you can zoom in on a specific portion of the drawing.

The print and plot functions allow you to print drawings using a printer or a plotter. You can control many aspects of printing and plotting. You can print the same drawing in different sizes by applying the appropriate scale factor. You can plot the drawings with specific colors, pen thickness, and line types.

Data Storage and Management

The data storage and management module allows you to store and manage drawing data. Through the use of the functions in this module, you can store drawings as files on the hard disk. You can manage the files in directories and sub-directories, and move, copy or delete them as needed.

CADD data management functions also let you translate drawings created by other CADD programs. These functions convert drawing data to a generic format that can be read by any CADD program. Data exchange format (DXF) is one of the common data translation formats used by CADD programs. There are a number of data exchange formats available.

System Control

The system control module (also known as system defaults) allows you to control how CADD works. CADD programs are designed for a broad range of professionals, including architects, designers, engineers and surveyors. With the help of system control functions, you can set the working environment of CADD to suit your needs.

Example: You can set the type of units that you will be using, the accuracy of the units, a style for dimensions and text, colors, layers, line type in a drawing, etc. Additionally, you can customize screen menus, the display of colors on the screen, resolution of the screen, size, the speed of the cursor, etc.

You can also specify whether the selected defaults should apply to a single drawing, to a specific project, or to all the projects in a specific category. The defaults can be set on a temporary or permanent basis.
 

Special Features

CADD programs usually offer a number of special features that make working with CADD easier and allow you to automate many drawing tasks. For example, you can create layers in a drawing that allow you to segregate drawing components. You can develop spreadsheets and databases that can be used to create many types of project reports. You can create three-dimensional (3D) drawings, such as isometrics and perspectives, with the help of 3D functions. You can also accomplish many other automated tasks with the help of macros.

The number of special features a CADD program has or how elaborate they are varies from one program to another. Some vendors sell specialized features as separate packages, while others include them in a single package. It all depends how a program is written, how big or small it is, and how it is sold.

Important Tip:

The functions of CADD are like the tools of a handyman. All of the tools are essential for working. Some are used more frequently than others are, but each has its own importance.
 

CADD user interface provides the environment and the tools that allow you and the computer to communicate. Each CADD program establishes an environment that best suits its purpose. The goal is to make working with CADD efficient. Most programs use a Graphic User Interface (GUI) to communicate with the user. The GUI provides visual aids for quick data entry. You are given tools to select functions, enter textual or mathematical data, locate points in the drawing window, select objects in the drawing window, etc.

The following are the most common ways to communicate with CADD:

• Using the CADD menus
• Entering commands in the command window
• Using the tool buttons
• Using the dialog boxes
• Working in the drawing area

Note: The above topics are described in detail in CADD PRIMER.

Note: CADD PRIMER is illustrated with more than 100 diagrams. The above diagram is an example from CADD PRIMER showing CAD tool buttons.