Normally the file is called XFDMaster.lha
the .lha at the end means it's an archive,
just like a zip for windows. You need the Lha
executable in order to decrunch it.
The command to decrunch using lha is, from a shell :
lha -x x xfdmaster.lha RAM:
The check in your ram disk, there should be an
installer.
Good luck!
