Quote Originally Posted by curious aardvark View Post
what does it do ?
I run my machines on the AT Mega2560 + a 1.4 Ramps board.

You can buy both for about $30 now, including drivers... so yeah it's a very cheap option to buy the essential brain of your 3D printer. The Ramps board fits on top of the AT mega

You download the marlin or similar firmware, flash the AT mega chip with it, and then it's a matter of tweaking the code for your printer and RAMPs / endstops, limits etc.

example

http://www.ebay.com.au/itm/Mega-2560...item1e839b5b06