I have several zips that I use to transfer file from my Macbook Pro (Lion) to System 6.0.8 and System 7 boxes. Some of them work great but some of them are locked on the Lion machine while the work on System 6. Some of them work on Lion but will not mount on System 6 or 7.

Does anyone know how to format a Zip disk so it mounts unlocked on Lion, System 6, and System 7?