System file

The System file is a special file, or suitcase, usually stored within the root level of the System Folder.

System file before HFS
Before System 2.1, which introduced the Hierarchical File System (HFS), the System file just lay on the root level of the MFS volume; any folders were cosmetic and could not be nested. Its contents were not accessible to the user except through Font/DA Mover (for consumers) or ResEdit (for developers).

System file before System 7
The System file appeared as a classic Macintosh icon and was typically stored in a System Folder which would indicate whether it was "blessed" by showing a small System icon on the folder icon. It contents were still inaccessible except through Font/DA Mover (for consumers) or ResEdit (for developers).

The System file in System 7 to Mac OS 9
With the release of System 7, the System file was displayed as a user-accessible suitcase. The following items could be dropped onto the System file (or be rerouted to the System file if it was dropped on a closed System Folder icon in Mac OS 8 through Mac OS 9):


 * Keyboard layouts
 * Fonts (until System 7.1)
 * Function keys or Fkeys
 * WorldScript files
 * System 7 Sounds

The System file in Mac OS X
The System file in Mac OS X was relocated to System > Library > CoreServices, and is no longer openable. A double-click will result in the error dialogue box, stating "Item "System" is used by Mac OS X and cannot be opened".

The System file in list views
In Mac OS X, the System file appears in list views as a document icon with the upper-right hand corner folded down.

Before Mac OS X, however, the System file appeared in list views as a document icon with the upper-left hand corner folded down.