EXECUTE [ZSHELL] source

* "EXECUTE source" executes the AmigaDOS script file of name "source"
  using an AmigaDOS shell, so no compatibility problems should occur.
  However in AmigaDOS scripts you cannot use ZShell-internal commands.

* To execute a ZShell script you have to set the  S-protection flag 
  and then you can execute it treating like a normal  command 
  or you have to use "EXECUTE ZSHELL scriptname".
  All ZShell commands, as well as commands from disk are valid within a
  ZShell script file.

* You can break scripts by pressing CTRL-D.

eg.   execute install_hard_disk
      execute zshell s:zstart