The Portobello & District Directories for 1889-90, 1892-93 and 1894-95 have been digitised by the Internet Archive and National Library of Scotland and are available to view online:
http://www.nls.uk/family-history/direct ... Portobello
http://www.archive.org/search.php?query ... tobello%22
Various formats on the archive.org page - view online, PDF plus various ebook formats. The digitised versions are available under a licence; PDFs attached.