March 1, 2010 Patch (Portal)

{{Patch layout
 * game = portal
 * source      = http://store.steampowered.com/news/3533/
 * source-title = Portal Update Released
 * before      = June 23, 2009 Patch (Portal)
 * after       = March 3, 2010 Patch (Portal)
 * notes       =

Portal
}}
 * Changed radio transmission frequency to comply with federal and state spectrum management regulations