The latest version of Iomega software is 5.5.1. This extension allows you to read files from a Zip or Jaz disk, write files to a Zip or Jaz disk, and run the Tools or other software from your Zip or Jaz disks. The only difference is that when using the Guest program to provide access to your drive, the Iomega Driver does not load automatically each time you start or restart the Macintosh.