(1) Root No, Tree No This, the default configuration, is known as full logging. All directories and files on the disk are logged, which takes a finite time. This is the best method if your total number of files is such that you have no memory or time problems.
(2) Root No, Tree Yes Displays the full directory tree, with a + against each entry to indicate that it has not been logged. Uses very little memory, but offers virtually no time saving over (1), as each directory on the disk still has to be read.
(3) Root Yes, Tree No This displays only the first level of subdirectories below the root, with a + against each, and the files in the root directory. Uses very little memory and no time, as only the root directory is read.
(4) Root Yes, Tree Yes This is similar to option (3) except that the files in the root directory are not logged.
If you have a large number of files on your disk, I would recommend either (3), which I use, or (4).
Having achieved partial logging, the next step is to fully log a disk when needed, and then to revert to partial logging when the memory is required for other purposes. These can be achieved with the Alt-L command, but as there are short cuts for all its options I will describe only these. They involve the four keys Home, +, - and *.
* fully logs a branch. To fully log a complete disc, first move to the root directory with Home, then key *. Expect the logging to take a finite time on a well-filled large disk.
- releases, i.e. unlogs, a branch. Only the directory name will then be displayed, with a + alongside to indicate that it is not logged.
+ will log a branch to first level only, with a + alongside every directory.
Thus to revert from a fully logged disk to 1st-level directory logging only, equivalent to (3), go to the directory window and key Home, -, +.
An alternative way to achieve this is with the Release Disk command, Alt-R D. Select the current disk to release and to switch to; e.g. if currently logged to C, key Alt-R D C C. The Release Disk command is probably more useful for releasing discs other than the current one to free as much memory as possible.
Postscript
Sometimes a lack of memory can be helpful. Normally when you View a .ZIP archive file, XTree will display the directory of the files in the archive. The other day, with the DISK box showing 6010 memory blocks free, I tried to view a .ZIP file and received an "Error: Insufficient memory viewing file" message. When I then hit Esc I found that XTree had entered the normal View mode, showing the contents of the file in the normal Dump display. With adequate memory, the only way to achieve this would be to change the file extension to something other than ZIP before Viewing.
Tom Ruben