Fri Jan 30 15:41:47 EET 2015

Looped circuit solving math problem? (clockLESS)

This might be gross nonsense, but at best might be crazy opportunistic idea.
Take a combinatorial circuit (NO CLOCK), loop the inputs so it has neither inputs nor inputs and power it on. If it reaches stable state and it is logically consistent, this will represent some boolean formula.
An example of significant importance is if the circuits computes the MD5 hash function restricted to 128 bits of inputs. Connect INPUT_i to OUTPUT_i for 0 < i <= 127. Logically consistent stable state is MD5(x)=x.
There is math obstruction (check SE link) about which I don't care since it just makes the idea "Monte Carlo". There is technical obstruction too (SE and cpunks links).
A very simple technical experiment will be of interest to me:
Take n-bit full adder (addition modulo 2^n) and one or more inverters. Loop many inputs to a single output using the inverters between if necessary until the creature is fully looped. Loop in a way a solution exists. The inverter is to avoid the trivial all zeros solution.
Power on.
On cpunks "coderman" called this "adiabatic bruteforce" and suggested it fails on current circuit technology.
Bounty 2 liters beers at local prices for the adder experiment whatever the result is.
SE link
cpunks link

Posted by j | Permanent link