EXECUTE source

* Executes the ZShell script file of name "source". All ZShell
  commands, as well as commands from disk are valid within a
  script file.
* If the S-protection-bit (see  PROTECT ) of "source" is set, you do
  not need to type EXECUTE, just use "source" like a command.
* You can break scripts by pressing CTRL-D.

eg.   execute install_hard_disk