Alfons3/Generation_7_Electronics — comment on commit 1e0f96d3a5e5320c3f7c8d44f04c6388ad298e91
File:  line 0
By Alfons3:

It's more then I need for a SD card and I don't know what else should go up to the Extension board.
If you place the pins far away from the ATmega the extension board will cover some jumpers. I don't know if this is a problem but I tried to avoid it. For routing of course a bigger board would be better.