There was a mechanical Turing machine shown at Makers Faire UK. Supposedly it was built only using hand tools and scrap parts. I'd say that's close enough to a

There was a mechanical Turing machine shown at Makers Faire UK. Supposedly it was built only using hand tools and scrap parts. I'd say that's close enough to a hand-built computer. http://hackaday.com/2011/03/25/mechanical-turing-machine-can-compute-anything-slowly/ http://hackaday.com/2011/03/25/mechanical-turing-machine-can...