Menu: Edit > Undo
Default Shortcut Key: Ctrl+Z
Macro function: Undo()
The Undo command can be used to reverse the effect of the most recent change to the current file. Successive Undo commands will have the effect of stepping back in time, with each command undoing the previous change, until the limits of Undo become exhausted. If a change is undone which you'd like to get back, the Redo command can be used to 'undo undo'.
By default, cursor motion changes will also be undone. For example, if you're editing mid-file and then jump to start of file to check something, Undo can be used to return you to your previous location. If you prefer that cursor motion commands not be stored for Undo, uncheck the relevant option on the Configure | Preferences | Editing dialog page.
The Undo command does not affect the content of the current clipboard.
The size of the Undo buffer (in bytes) can be controlled on the Configure | Preferences | Editing options page. The option is titled Undo buffer size. Values between 2048 and 65535 may be entered. The default value is 65535, which is also the maximum. There is little reason to select smaller values, as the memory cost is small compared to the utility that Undo provides.
Undo information is stored separately for each file, so there is no chance that excessive editing within one file can exhaust the undo capacity in another file.
An option is also provided to control whether or not Undo is allowed after the Save command. This option is titled Allow Undo after File Save