[NTG-pdftex] Urgent help needed (Document open settings)

Dear Colleagues -- I am being driven to distraction by my inability to persuade PdfTeX to set the default "Document open" option to "Fit Visible". I know that Hyperref can accomplish this, but I am working in TeX, not LaTeX. I assume that an appropriate incantation to \pdfliteral will be all that is required, but so far Google has failed to throw up any useful hints as to what to pass to \pdfliteral to accomplish this. Your help will be much appreciated. Philip Taylor