Comment by gioele

I hoped the article had a look at which parts of those ISAs were reversible, and thus did not dissipate energy.

For those interested, there is a master thesis from the '90 that discussed a prototype reversible ISA + RTL that wasted (in theory) no power for the logic (non-IO) parts [2].

[1] http://en.wikipedia.org/wiki/Reversible_computing [2] http://dspace.mit.edu/bitstream/handle/1721.1/36039/33342527...