Wow it worked, i'm very impressed!

I can't for the life of me understand how the payments made their way to my sms account. 

First I made a registration with my email and a username / password.

Then, since I had the bitcoin client on another computer, I made a payment to the bitcoin address at smsz.net

How could smsz know how to credit my specific account? 

Did anyone see that movie "Mickey Blueeyes"?

One of the gangsters is in therapy and makes lousy paintings of his worst deads.

Then the other gangster sells them at an auction, the presumed bidder is one of their associates, which needs a legal way to deduct his payments for "services".

Only prob. is now that the painter is famous, other people starts bidding fantasy prices for the pictures as well.

Hillarious, and educative.

Personally I don't think I'd ever have to explain where I got black money from, there are plenty of spending-holes that don't show to stuff them in :-)

Wow thats some really impressive calculations.

$9k... to bad xmas is over for this time :-)

Smart idea to pipeline the adders, does it mean you spend more flip-flops but not more gates?

I was thinking of getting an old-fashioned xc3s500 for a reasonable price, at 1k-1.5k flip flops maybe it would be possible to fit one out of the 64 of these
pipelined sha modules into one chip?

So, if I'm lucky I could get it running at 60-70 MHz meaning a full sha would take about 1us and that would give me 0.5 MHash/sec, right?

Its almost as fast as my old computer which runs at 0.7 MHash/s :-)

aha, so in general any given block with the nonce as the only variable is not likely to have a solution at all?

Are there some statistics on how often the non-nonce parts of the current block changes?

hehe now I know why I like this so much, its like the original gold-rush, few of the miners got rich, but many of the providers of the pots an' pans did :-)

hello!

am I rightly informed that the nonce is only 32 bits?

Does this in turn mean that there are "only" 2^32 or about 4 billion (4E9) combinations to try for each block?

If so, then when network hashing capacity reaches 4 000 000 kHash/sec the block would be solved in one second on average?

This contradicts the onlïne hash-rate calculator, which states about 4 hours, at present difficulty.

Sorry if this has been up before, but I'm really puzzled..

Maybe this is not a new use of bitcoins, but I thought before of using stamps for emails. (Stamps as in old-fashioned letter stamps).

If we could have our emails stamped in some way with bitcoins, then one could configure ones mail reader to show stamped (and payed for) emails with a priority.

Suppose we payed maybe only a fraction of a cent per email, that would make it more expensive for spammers to reach out.

(You could still send your emails free but that would mean it would end up in the junkmail folder of the receiver)

Having a few billion emails stamped a year would mean a huge turnaround for the bitcoin systems.

As said before, this is not a new use, but the cheapness of bitcoin transactions might make it practical and possible.

60 MHz

Hmm, yes I discovered that myself today.. .really...

The numbers where though of as a maximum possible with-all-the-luck-you-can-have.

Unfortunately 11 MHash/sec is not to impressive either...

But then one has to remember that this is not the final implementation, it isn't even runable as it is.

Please correct me if I'm wrong but I thought that the maximum clock inside the spartan was about 300 MHz?

Also I'm confused about the hash definition, do we define the bitcoin hash as two regular hashes?

Another thing that really puzzels me is the nounce, will it always be at offset 12 and never be more than 32 bits ?

It's amazing the we have so many knowledgable people on this board.

Yeah that seems about right, that altera board contains 12 times as many 4 input lut's as an xc3s500 spartan module in the GOP module. 12 x 27 = 324 times the 11 MHash in my calcs => 3564000 khash/sec input in the calculator gives you 4 hours for a block. Counting at 2000 blocks per year you get 100000 BTC or $25k a year assuming moderate difficulty increase.

So I guess the graphics cards beat the crap out of the fpga's. But what about power consumption? Also the graphics cards need a motherboard, host cpu etc.

Wonder how far you could optimize the gate count?

Putting a few hundreds of these DIP formfactor boards together would also give you a priceless 80's feeling :-)

http://shop.trenz-electronic.de/catalog/product_info.php?products_id=81

hello again!

Just to clarify, I did run the program under simulation only, but I also compiled the module into the Xilinx synthesis tool (ISE) just to see how much space it would take in the chip. (I don't even own a spartan fpga :-)

A full implementation.. well I'm just trying to understand the criteria for a found block, not being an expert in cryptography. This will also need to be in hardware, I think, so the fpga only reports back when it has found something.

I just checked in at the calculator (http://www.alloscomp.com/bitcoin/calculator.php).
What is the correlation between the "difficulty factor" and the "hash target"? Why do we use two concepts?

I also checked in to the bitcoin code, but it seems that the routine I'm trying to accelerate (ScanHash_CryptoPP) is only checking for a certain number of zeroes and then returning.

Where is the code that checks if you've found a block? I guess it would only be a simple less-than compare in the hardware.

The code would also need to contain some uart comms or similar, I thought of broadcasting the request to all devices and then daisy-chaining the results back so that the "winning" device could break the chain and report back to the host computer.

Hello!

I converted the sha256 available in opencores.org into vhdl, just to see what to expect.

I got an xc3s500E about 1/3 full on the logic gates, so with a shoe horn one could maybe fit 3 cores into one of these. That does not include the communications with the host, nor the "less than" compare if the result is below the current threshhold.

 (I used an antique ISE (8.something) so maybe newer versions will compute better).

Assuming a maximum of 300 MHz and about 80 cycles to read in, process and output the result (8 + 64 +

You'd get 3*300/80 ~= 11 Mhash/s

This device can be had on a nice DIP socket (GOP modules) at about 60 EUR.

If you want to run this simulation (only tried on Linus), you need ghdl and gtkwave packages (and probably some more stuff that I forgot).

The tar in the attachement contains the synthable file sha256.vhd and the test_sha256.vhd and a simple Makefile.

bar codes combined with printed hex numbers for backup?

But do you still (on average) get bitcoins proportional to the amount of CPU that you chip in?

Or do the fastest node always "win" ?

Can one really change the algorithm on-the-fly like that?

Doesn't it require a majority of the nodes agreeing to run the new software?