Here is a guy that has videos of him building a TPU:

https://www.youtube.com/user/TPUBruce/videos

Here's the calculations and stuff:

http://www.overunity.com/12000/bruces-sm-tpu-engineering-information-for-repl

And here's a thread:

http://www.overunity.com/index.php?topic=2300.0


Interesting stuff.  I don't know if he ever finished it though...

Here is the list of videos in order:

part 1 - https://www.youtube.com/watch?v=b6GxysnuJMI
part 2 - https://www.youtube.com/watch?v=ihSlPkbpPwg
part 3 - https://www.youtube.com/watch?v=oy71bXcoveE
part 4 - https://www.youtube.com/watch?v=6eCXniDnjjk
part 5 - https://www.youtube.com/watch?v=jb_Pd-whgLE
part 6 - https://www.youtube.com/watch?v=m-iPCVf0f1M
part 7 - https://www.youtube.com/watch?v=9_IE4R0LPQE
part 8 - https://www.youtube.com/watch?v=X7kO8GRmXs4
part 9a - https://www.youtube.com/watch?v=1DLklFp-xDI
part 9b - https://www.youtube.com/watch?v=VG_4SHX-POU

does this help?

THE BOB BOYCE TPU

http://ebookbrowse.com/bob-boyce-tpu-pdf-d167793919

INFO ON THE HEX CONTROLLER

http://www.overunity.com/8289/bob-boyce-hex-controller/15/

Quote from Total Psychonaut on May 24th, 2012, 10:54 PM

does this help?

THE BOB BOYCE TPU

http://ebookbrowse.com/bob-boyce-tpu-pdf-d167793919

INFO ON THE HEX CONTROLLER

http://www.overunity.com/8289/bob-boyce-hex-controller/15/

Every bit helps!