Bitcoin mining on a calculator? :)

[Dave Britten]

(05-27-2015 08:21 AM)Les Bell Wrote:  

(05-26-2015 06:19 PM)Dave Britten Wrote:  Yeah, heavy emphasis on the difference between "theory" and "practice" on this one.

Given that specialised ASIC BitCoin mining rigs run at 1.15 TeraHashes per second - and the serious miners run clusters of them - it's going to be pretty hard to win the race and be first to find the right nonce in order to claim the 25 BitCoins reward.

Mere details! One need not take first place to finish a marathon. Though it certainly helps with obtaining sponsors.

I've (partially) implemented the SHA256 routine on my 48SX by following what he's doing in the "by-hand" video, and it's running 64 rounds in 47.44 s without any really tight optimization. It's not really a complete program, as his video doesn't explain how to obtain the final output, and I didn't bother finding the 64 values of K for each round, so I'm just using the first one over and over, but in terms of pure speed, it's not bad. If there were any practical use to this, I might get all the values of K and figure out some of the other details.

If your system has bitwise functions, then you can easily calculate the majority, choose, and parity functions as follows:

Maj(a,b,c) = A and B or A and C or B and C
Ch(a,b,c) = A and B or not A and C
Par(a,b,c) = A xor B xor C

No need to waste cycles manually looping and comparing each bit individually.