DEFAULT_FILESYSTEM specifies the default file system to be used for all file I/O. The default value on HP e3000 machines is MPE. If you want to use ACUCOBOL-GT's Vision file system instead, add the following to the cblconfig file:
DEFAULT_FILESYSTEM Vision
This tells the runtime to use Vision files instead of MPE KSAM files. In addition, if you specify Vision, the relative and sequential files will be in bytestream format instead of MPE format.