AutoCAD 2005 for Dummies

the sole operating system for AutoCAD. (AutoCAD 2005 works with Windows XP — both the Professional and Home versions — and Windows 2000.) Because of AutoCAD’s MS-DOS heritage and its emphasis on efficiency for production drafters, it’s not the easiest program to master, but it’s gotten easier and more consistent. AutoCAD is pretty well integrated into the Windows environment now, but you still bump into some vestiges of its MS-DOS legacy — especially the command line (that text area lurking at the bottom of the AutoCAD screen — see Chapter 2 for details). This book guides you around the bumps and minimizes the bruises.

Why AutoCAD?

AutoCAD has been around a long time — since 1982. AutoCAD ushered in the transition from really expensive mainframe and minicomputer CAD systems costing tens of thousands of dollars to merely expensive microcomputer CAD programs costing a few thousand dollars.

AutoCAD is, first and foremost, a program to create technical drawings; drawings in which measurements and precision are important, because these kinds of drawings often get used to build something. The drawings you create with AutoCAD must adhere to standards established long ago for handdrafted drawings. The up-front investment to use AutoCAD is certainly more expensive than the investment needed to use pencil and paper, and the learning curve is much steeper, too. Why bother? The key reasons for using AutoCAD rather than pencil and paper are

• Precision: Creating lines, circles, and other shapes of the exactly correct dimensions is easier with AutoCAD than with pencils.

• Modifiability: Drawings are much easier to modify on the computer screen than on paper. CAD modifications are a lot cleaner, too.

• Efficiency: Creating many kinds of drawings is faster with a CAD program — especially drawings that involve repetition, such as floor plans in a multistory building. But that efficiency takes skill and practice. If you’re an accomplished pencil-and-paper drafter, don’t expect CAD to be faster at first!

Figure 1-1 shows several kinds of drawings in AutoCAD 2005.

Figure 1-1: Tower, bridge, and plan — what do you want to draw today?

Why choose AutoCAD? AutoCAD is just the starting point of a whole industry of software products designed to work with AutoCAD. Autodesk has helped this process along immensely by designing a series of programming interfaces to AutoCAD that other companies — and Autodesk itself — have used to extend the application. Some of the add-on products have become such winners that Autodesk acquired them and incorporated them into its own products. When you compare all the resources — including the add-ons, extensions, training courses, books, and so on — AutoCAD doesn’t have much PC CAD competition.

The Importance of Being DWG

To take full advantage of AutoCAD in your work environment, you need to be aware of the DWG file format, the format in which AutoCAD saves drawings. In some cases an older version of AutoCAD can’t open a DWG file that’s been saved by a newer version of AutoCAD.

? A newer version of AutoCAD always can open files saved by an older version.

? Some previous versions of AutoCAD can open files saved by the subsequent one or two versions. For example, AutoCAD 2004 can open DWG files saved by AutoCAD 2005. That’s because Autodesk didn’t change the DWG file format between AutoCAD 2004 and AutoCAD 2005.

? You can use the “save as” option in newer versions to save the file to some older DWG formats.

Table 1-1 shows which versions (described later in this chapter) use which DWG file formats. 

Table 1-1 AutoCAD Versions and DWG File Formats

AutoCAD Version	AutoCAD LT Version	Release Year	DWG File Format
AutoCAD 2005 (“A2k5”)	AutoCAD LT 2005	2004	Acad 2004
AutoCAD 2004 (“A2k4”)	AutoCAD LT 2004	2003	Acad 2004
AutoCAD 2002 (“A2k2”)	AutoCAD LT 2002	2001	Acad 2000
AutoCAD 2000i (“A2ki”)	AutoCAD LT 2000i	2000	Acad 2000
AutoCAD 2000 (“A2k”)	AutoCAD LT 2000	1999	Acad 2000
AutoCAD Release 14 (“R14”)	AutoCAD LT 98 & 97	1997	Acad R14