You can change encoding of an existing repository location. This encoding will be used to translate file paths and commit messages from the client encoding to the server encoding and vice versa. The encoding does not affect the contents of file. You may use the editor encoding (available from the Workbench>Editors preference page) or resource encodings (available from the Properties>Info page of resources) to configure the Workbench to use the proper file encodings.
To change the server encoding of a CVS repository location:
Team programming with CVS
CVS Repositories
Creating a CVS repository location