Viewing the Memory/Versions Pane in Classic Preferences

The Memory/Versions pane shows details about the state of the Classic environment, including active applications, memory usage, and the version of Mac OS 9. This pane's information is similar to that provided by the "About This Mac" menu item in the Finder for Mac OS 9.

In the Active Applications area, all of the currently running Classic applications are listed with memory usage and allocations. In Mac OS 9, applications are assigned a fixed amount of memory in the Get Info window in the Finder, and that behavior persists in Classic. While native Mac OS X applications are able to use additional memory as needed, Classic applications cannot use more memory than they have been assigned. Symptoms of a Classic application running out of memory are out-of-memory errors, poor performance, erratic behavior, or crashes. If you see these symptoms, check the Memory/Versions pane to see if the application has used all of its memory allocation. If it has, you can quit the application, assign it more memory, and restart it.

Some Classic applications and drivers use background processes to provide their functionality. Selecting the "Show background applications" checkbox will add these processes to the list, helping you determine if you want to set Classic sleep time in the Advanced pane to Never.