http://bleaklow.com:80/2011/01/21/optiboot_on_arduino_pro_mini.html The newer Arduino boards such as the Uno include a new bootloader that takes up about 1/4 of the size of the old one. That means some extra memory can be freed up for applications. The new bootloader is known as Optiboot, and the site says "Compatible ... en Alan Burlison Fri, 21 Jan 2011 14:17:50 GMT Alan Burlison 2011-01-21T14:17:50Z en Alan Burlison http://bleaklow.com:80/