This page is dedicated to information about the CoCo 3. My own CoCo 3 has the stock processor (the Motorola 6809E), a 512K upgrade, using a Disto SuperController II, with a 5 1/4" single sided drive, as well as a double sided drive of the same size.
I've been doing nothing CoCo-related for ages. My CoCo's packed away somewhere, and I've found I'm more interested in things that don't relate to computers.