Auto Saves

You save drawing files for later use just as you do with other Windows applications. AutoCAD also provides automatic saving, backup files, and other options for saving.

When you are working on a drawing, you should save it frequently. Saving protects you from losing work in the event of a power failure or other unexpected event. If you want to create a new version of a drawing without affecting the original drawing, you can save it under another name.

The file extension for AutoCAD drawing files is .dwg, and unless you change the default file format in which drawings are saved, drawings are saved in the AutoCAD LT 2004 drawing-file format. This format is optimized for file compression and for use on a network.

Save Your Drawing Automatically
If you turn on the automatic saving option, AutoCAD saves your drawing at specified time intervals. By default, files saved automatically are temporarily assigned the name filename_a_b_nnnn.sv$. The file name is the current drawing name, a is the number of open instances of the same drawing file in the same AutoCAD session, b is the number of open instances of the same drawing in different sessions of AutoCAD, and nnnn is a random number generated by AutoCAD.

Files that are automatically saved are deleted when AutoCAD closes a drawing in the normal way. Saved files remain in the event of a crash or power failure. To recover a previous version of your drawing from the automatically saved file, rename the file using a .dwg extension.

Use Backup Files
If you turn on automatic backups, AutoCAD saves the previous version of your drawing files to a file with the same name and a .bak file extension. To recover the previous version of your drawing from a backup file, rename the file using a .dwg extension.

Save Part of a Drawing File
If you want to create a new drawing file from part of an existing drawing, you can use BLOCK or WBLOCK. With either command, you can select objects or specify a block definition in your current drawing and save them in a new drawing file. You can also save a description along with the new drawing.

Save to a Different Type of Drawing File
You can save a drawing to an earlier version of the DWG or DXF format or save a drawing as a template file. Choose the format from Files of Type in the Save Drawing As dialog box.

Reduce the Time Required to Save a Drawing File
You can reduce the time required to save a drawing file if you specify incremental saves rather than full saves. An incremental save updates only those portions of the saved drawing file that you changed.

When you use incremental saves, drawing files will contain a percentage of potentially wasted space. This percentage increases after each incremental save until it reaches a specified maximum, at which time a full save is performed instead. You can set the incremental save percentage in the Open and Save tab of the Options dialog box or by setting the value of the system variable ISAVEPERCENT. If you set the value of ISAVEPERCENT to 0, all saves are full saves.

To reduce the size of drawing files, it is recommended that you perform a full save (with IPERCENTSAVE set to 0) before transmitting or archiving a drawing.

To save a drawing automatically

1. On the Tools menu, click Options.

2. In the Options dialog box, on the Open and Save tab, select Automatic Save and enter a number in Minutes Between Saves.

3. Click OK.