via http://www.planetvb.com/modules/news...hp?storyid=358

Guy Perfect has made available the first public release of his "VB Sacred Tech Scroll", which is currently the most accurate and up-to-date inofficial Virtual Boy hardware documentation. The current version (0.9 WIP) is, according to the author, a rough draft that is more or less done, but still needs some revisions. Find the document under Development -> Documents in the main menu or directly by following the above link.