How MS-DOS 6.22 TREE Displays Directories

The TREE command in MS-DOS 6.22 is an external command-line utility used to generate a visual, hierarchical diagram of the folders on a disk. This article explains how the command renders directory levels on the screen, how it handles branch structures, and how its primary switches—/F and /A—alter the displayed output.

Default Visual Structure

When executed without parameters, the TREE command displays the directory structure of the current drive and working directory. It represents folder hierarchies using IBM Extended ASCII box-drawing characters (Code Page 437).

Subdirectories branch out from their parent folders using vertical lines, horizontal lines, and corner connectors. Each subsequent level of nesting is indented to the right, showing parent-child relationships clearly:

  • A vertical line indicates a path continuing to deeper or adjacent folders.
  • A tee connector branches off to a sibling folder.
  • A corner connector indicates the last subdirectory within a given branch.

By default, the command ignores files completely and displays only the directory names.

Command Syntax and Targeting

The basic syntax for the utility in MS-DOS 6.22 is:

TREE [drive:][path] [/F] [/A]

If a drive letter or specific directory path is provided (for example, TREE C:\DOS), the command begins rendering from that specified root or directory rather than the current working path.

Displaying Files with the /F Switch

To view both the directory layout and the files contained within each directory, the /F switch is used:

TREE C:\ /F

When this flag is active, TREE lists all files located in a folder immediately below that folder's name before rendering any subordinate directories. The filenames are indented under the folder header, preserving the visual flow of the tree while giving a complete file listing.

Changing Character Sets with the /A Switch

MS-DOS 6.22 includes the /A switch to replace Extended ASCII line-drawing symbols with standard 7-bit ASCII characters:

TREE /A

When /A is specified, the graphical lines are converted to basic characters:

  • Hyphens (---) represent horizontal branches.
  • Backslashes (\) represent terminal branches.
  • Plus signs (+) represent intermediate branching nodes.
  • Vertical bars (|) represent vertical continuity lines.

This mode is designed primarily for redirecting tree output to legacy printers, serial terminals, or non-IBM compatible displays that cannot render high-order ASCII box characters correctly.

Managing Long Outputs

Because the TREE command outputs its diagram continuously to standard output, viewing large directory structures on a standard 80x25 character display often causes the output to scroll off the screen. To control this, users typically pipe the output through the MORE filter:

TREE C:\ /F | MORE

Alternatively, the output can be redirected to a text file for review in the MS-DOS Editor:

TREE C:\ /F /A > DIRLIST.TXT