Before you upgrade to any new version of CAD software, check the minimum system requirements to make sure you meet them, or can budget for a hardware upgrade as well. Otherwise, you may find yourself underpowered or over budget. The minimum requirements for 32-bit AutoCAD 2011 running on Windows Vista or 7 are a 3GHz or higher Intel Pentium 4 or AMD Athlon dual-core processor with SSE2 technology. For Windows XP, you’ll need at least a 1.6GHz processor. In addition, the software requires at least 2GB RAM, 1.8GB disk space for installation, and a 1,024x768 true-color display. If you’re planning to do any 3D work, you’ll also need an additional 2GB hard disk space and a 128MB or more Direct3D-capable graphics card.

Whenever you’ve lost your bearings, type Plan at the command line, followed by two Enters. This will return you to the drawing’s plan view.

If you want to turn off Selection Preview, perhaps because it makes it harder to snap accurately, go to the Selection tab of the Options command (found in the Tools menu).

Caption: Turn off Selection Preview by unchecking the boxes under Selection Preview.

Uncheck the selections in the Selection Preview panel on the left middle side of the tab. If you don’t turn Selection Preview off completely, click on the Visual Effects Settings buttons for additional selection preview features to change.

Caption: In the Visual Effects Setting dialog box, you can change how the selection preview is shown on screen.

Under Selection Preview Effect are options for how the selection preview appears on screen. You can select dashed lines, thickened lines, or both. Finally, click on Advanced Options to exclude certain types of objects from Selection Preview. The main benefit to excluding certain types is to speed up the preview.

Caption: In the advanced box, you can exclude certain object types from selection preview to speed things up.

Alternatively, you can change the settings of the following system variables directly at the command line.

SELECTIONPREVIEW controls the display of selection previewing. Its settings are:

0 = Off
1 = On when no command is active
2 = On when a command prompts to select an object
3 = Always on (default setting)

PREVIEWEFFECT controls the visual effect used to preview object selection. Options are:

0 = Dashed lines
1 =  Thickened lines
2 = Dashed thickened lines (default setting)

PREVIEWFILTER excludes certain object types from selection previewing. Its settings are:

0 = Exclude nothing
1 = Exclude objects on locked layers
2 = Exclude objects in xrefs
4 = Exclude tables
8 = Exclude mtext objects
16 = Exclude hatch objects
32 = Exclude objects in groups

Add values to exclude more than one object type. For example, enter 12 to exclude both tables and mtext objects, but nothing else.

The system variables DIMCLRD and DIMCLRE control the colors of your dimension lines and extension lines, respectively. Their values override any colors assigned in the dimension style. The default setting for both variables is 0, for Byblock. If your dimension and extension lines start appearing in a color other than that assigned in the dimension style, check to make sure these variables haven’t been changed from the default setting.

When you have multiple files with multiple xrefs that have similar file names and identical layer names, you can use some tricks to speed up repetitive tasks. Here’s an example from the AEC world that can be applied to similar situations (sorry, I couldn’t think of a better example). Suppose you’re designing a 12-story building. You have a drawing for each floor. The file names follow the convention Floor-xx.dwg, where xx is the floor. Layer names are the same in all of the drawings. You want the layer states for each design to be the same. You can’t just export and load the layer states from one drawing to another because the xref-dependent layer names also contain the floor number, so those names are different in each drawing. Go ahead and set up the layers as you want them in one of the drawings—let’s use Floor-01 for our example. Name and save the layer state in Floor-01. Export the layer state to an external file (Floor-01.fas).

Caption: Use the Layer States Manager to create new layers states as well as to import and export them.

Open a copy of Floor-01.fas in a text editor such as Notepad. Replace the floor numbers as needed throughout the file (you may want to do this with Change/Find rather than Change All to avoid creating unexpected problems).

Caption: FAS file as it appears in Notepad.

In the example above, the xrefs use the format xth floor to designate the different stories, so you might change 1st to 2nd (then to 3rd, 4th, etc.) Save the file as Floor-02.las. Now import and apply Floor-02.las to the Floor-02.dwg file. Continue on through all your floors. It can get a bit tedious, but not so tedious as changing the layers in each drawing.