Print Page - Programmer Question: How to get the initial nonce ?

Hello, I am a newbie here trying to get my head around the hashes mechanism, I am able to call getwork and gotten the:

id
data
hash1
target
midstate

I was looking at an example by "Taro Kudo & friends", and I have two questions:

My question is
1: Why does he do "2809801765-1000000" ?
2: Where did he even get those numbers, how does he "know" the answer of the stnonce before any calculation even began ?

This is his example data:

Code:

var midstate:String = "d9dcb3f73ba7083619c3d080e85dace2590fe00398dbbf388579e281cacf233f";
var data:String = "00000001041044ce884d97e1eb77e893d2fa6fdce53faaee42784297000007330000000052c68b98b11cefa06739f5d3a8ffddad25adfac6e0d360a496b8d82f3b40301c4e2581741a0abbcf00000000000000800000000000000000000000000000000000000000000000000000000000000000000000000000000080020000";
var hash1:String = "00000000000000000000000000000000000000000000000000000000000000000000008000000000000000000000000000000000000000000000000000010000";
var target:String = "ffffffffffffffffffffffffffffffffffffffffffffffffffffffff00000000";

This is his example code:

Code:

import myClass.BitCoin_Judge;
stop();

var Judge0:BitCoin_Judge = new BitCoin_Judge(midstate,data,target);
var start_time:uint = (new Date().time)/100;

var nonce:uint =　2809801765-1000000;
var stnonce:uint = nonce;

status.text = "Start:" + stnonce;

var timer:Timer = new Timer(1000/12);
timer.addEventListener(TimerEvent.TIMER, onTimer);
var repeat:int = 3000;
var scannedunit:int = 0;


function onTimer(evt:TimerEvent):void
{
	for (var ii:int=0; ii<repeat; ii++)
	{

		if (Judge0.judgement(nonce))
		{
			hps.text = "solve";
			current.text = "nonce= " + nonce;
			timer.stop();
			removeEventListener(Event.ENTER_FRAME, update);
			break;
		}

		if (nonce == 4294967295)
		{
			hps.text = "over flow";
			timer.stop();
			removeEventListener(Event.ENTER_FRAME, update);
			break;
		}


		// Status report for browser
		if (nonce % (repeat*10) == 0)
		{
			var total_time:uint = (new Date().time)/100 - start_time;
			hps.text = ((((nonce - stnonce) * 10) / total_time) / 1000).toFixed(2) + " KH/S";
			current.text = "Scanned hashes " + Math.round((nonce-stnonce)/1000) + "K";
		}

		nonce++;
	}


}
timer.start();


function zPad(num:String, len:int)
{
	var out:String = "" + num;
	while (out.length != len)
	{
		out = "0" + out;
	}
	return out;
}

addEventListener(Event.ENTER_FRAME, update);
var ms_prev:uint;
var ms_prevS:uint;
var fps:uint;
var timer_c:uint;
var repeatControll:Boolean = true;
var fr:int=(1000/(stage.frameRate*0.5));


function update(e : Event):void
{

	timer_c = getTimer();
	if (repeatControll)
	{
		var num:int = repeat * (fr / (timer_c - ms_prev));
		if (num>1000)
		{
			repeat = repeat - (repeat - num) * 0.1;
		}
		else
		{
			repeat = 1000;
		}
		repeatControll = false;
	}
	else
	{
		repeatControll = true;
	}

	if ( timer_c - 1000 > ms_prevS )
	{
		ms_prevS = timer_c;
		fpstx.text = "FPS: " + fps + " / " + stage.frameRate + " X repeat " + repeat;
		fps = 0;
	}

	fps++;
	ms_prev = timer_c;
}

Bitcoin Forum

Other => Beginners & Help => Topic started by: Toddler on April 10, 2013, 09:26:13 AM