Aleppo Codex

A wonderful description of the Aleppo Codex and its history is on the website of the Shrine of the Book in Jerusalem. Click on “A Wandering Bible: The Aleppo Codex” at the left.
 
You can view the entire Aleppo Codex online here, a digitization made by Ardon Bar-Hama. Unfortunately, there is no index to let you know at what part of the Bible you are looking.