Jameco (www.jameco.com) still lists the 6551 at about US$4.00 a pop; granted: it is the 1MHz rated ACIA... but perhaps all that's needed for a given CoCo project. -- RP On Wed, Dec 15, 2010 at 6:13 AM, Mark Ormond <markormond at mtxsystems.com>wrote: It would be nice if you could offer the board with the 6551A, that's the > only hard to come by part. >