Technical Note OV05

The Desktop File's Outer Limits

CONTENTS Introduction References Downloadables

There is a limit to the number of applications/files that the Finder can "see" on a single volume. This limitation is imposed by the Desktop file. The Desktop file is a resource file that the Finder uses to keep track of information about files and applications, including Finder file comments (Get Info comments), and how these files and applications relate to each other. [Aug 01 1988]

Introduction

Because the Desktop file is a resource file, the maximum number of resources it may contain is currently 2727 (refer to M.TB.MaxResInFile). To illustrate this limitation of the Desktop file, here are some example applications and how their entries currently affect the Desktop file.

• The Finder puts a single resource into the Desktop file (the Finder is not on the disk).
• MacWrite puts 10 resources into the Desktop file.
• MacPaint puts 9 resources into the Desktop file.
• MacDraw puts 8 resources into the Desktop file.
• MacWrite and MacPaint together put 20 resources into the Desktop file.
• MacWrite and MacDraw together put 19 resources into the Desktop file.
• A generic application (no BNDL resource) or a file without any Finder file comments does not put any resources into the Desktop file.
• Finder file comments put a single resource into the Desktop file.

As you can see, it is difficult to accurately predict how many applications/files will fit on any single volume. Clearly, the more information an application or file carries with it, the larger its "entry" in the Desktop file. This is normally not a problem, but with the advent of very large capacity media, it is possible to reach this limitation by creating a single volume with too many applications/files.

Back to top

References

Inside Macintosh Volume 3, Page 10

Inside Macintosh Volume 4, Page 243

M.TB.DeskTopFile

M.TB.Bundles

M.TB.MaxResInFile

Back to top

Downloadables