In general when saving or loading a file the following prompt appear in a top right window:
SAVE [or LOAD] [type] - filename (no ext) .[extension] will be added
(change drive or dir-d) [current path]
list-?, quit-q, default [ filename]
For example, if you are running DDLab from the directory
``c: 
ddlab'' and loading a screen image the prompt will
appear as follows,
LOAD SCREEN - filename (no ext) .NAT will be added
(change drive
or dir-d) C: DDLAB
list-?, quit-q, default myimage
To load (or save) enter a legal filename (without the filename extension, which is automatically added), or enter ``return'' to accept the default filename ``myimage``. If the file is not found, the following message appears,
No such file or directory, RETURN-continue