The Rev2 build instructions are now available on my blog:

http://sweetlilmre.blogspot.com/2015/03/building-tapuino-r2.html

Rev 2 is a simplification of the build and has fewer parts. Additionally the code is significantly more capable now.

I have also provided a schematic and board file for single layer home etching and in partnership with a great bloke from Spain who goes by the name of spcbm, provided a really nice dual layer board that includes muxing capability and a connector for a physical Commodore Datasette.

You can find code and layout files here: https://github.com/sweetlilmre/tapuino

With muxing you are able to use the Tapuino as a source / target for a real Datasette allowing you to archive tapes to .tap format and even restore .tap file to a physical tape! (pretty awesome, I had to find some tapes to try this out :))

If you want to buy a Tapuino, please support spcbm, he is selling kits and boards with my blessing. Currently he is out of stock (who knew this would be so popular!), but check the forum thread here, and perhaps PM him:

http://www.amibay.com/showthread.php?70457-Tapuino-C64-Tape-Emulator-PCBs-kit-2nd-batch

You can follow the development thread here:

http://www.amibay.com/showthread.php?63166-Tapuino-the-20-C64-Tape-Emulator