Already asked this question here (http://"http://www.diystompboxes.com/smfforum/index.php?topic=75235.0"), but may be someone interested in this section, too:
Is ist necessary to program the PIC 12C508 to work as needed in this schematic of R.G.Keen?
Or just solder and everything's well?
(http://www.geofex.com/Article_Folders/footswitch_pancake/uc_pancakes.gif)
You need to give it a program to run. You always do with microcontrollers.