Sunday, December 29, 2013

Sarah Kay Quotes (Author of B)

"...She’s gonna learn that this life will hit you, hard, in the face, wait for you to get back up so it can kick you in the stomach. But getting the wind knocked out of you is the only way to remind your lungs how much they like the taste of air. There is hurt, here, that cannot be fixed by band-aids or poetry, so the first time she realizes that Wonder-woman isn’t coming, I’ll make sure she knows she doesn’t have to wear the cape all by herself. Because no matter how wide you stretch your fingers, your hands will always be too small to catch all the pain you want to heal. Believe me, I’ve tried...."

Saturday, December 28, 2013

Official statement about the maintenance fee : CEX.IO

Jeffrey told this on Nov 01 13:05
Below is the official statement about the maintenance fee:
The fee will be implemented on November 12th 2013.

The maintenance fee is estimated as $0.30 / kW*hour: 
$0.17/kW electricity cost + $0.09 data centre upkeep + $0.04 hardware repair/maintenance. 

(The power consumption of 1 GHS is 1.5W per hour)

The fee will be billed in BTC per mining share. The estimated fee is 0.000000002695 BTC/share, which makes it ~4% of total mining profit.

The fee will be adjusted according to the BTC/USD exchange rate.

About the hardware maintenance:
We will charge $0.09 for the data centre upkeep + $0.04 for hardware repair/maintenance.

Handling 600+ kW mining equipment is quite challenging. This involves MANY people working at the backend, who: 
Replace dead chips
Fix PCB issues 
Upgrade electricity links 
Improve mining software to reduce stale shares (we have stopped delivering stale shares for purchased GHS).

The maintenance fee is only applied to GHS purchased at CEX.IO. (Personal miners are not affected)
More details can be found here: https://cex.io/maintenance

In case of any questions or issues - feel free to contact the support team, via support@cexio.zendesk.com 

We will be glad to help. 

CEX.IO will keep you informed about all the future updates as soon as they come.
Thank you for being with us.

Best Regards,
CEX.IO Team

Friday, December 27, 2013

A Treatise on CUDA Miner : Dogecoinmining

A Treatise on CUDAMiner
Thanks CBuchner for creating Cudaminer!
If this helped please upvote for other puppy miners!
I've added popular cards and configs to the bottom.
Disclaimer: I'm like every other shibe.. I can make mistakes, if something doesn't look right, please, please correct me! Thanks!
Some edits: A Minor Observation. -c 1 performs better than -c 2 generally.
Update: Place:
setx GPU_MAX_ALLOC_PERCENT 100
on a line before the cudaminer.exe line, you may get a little more performance out of the miner.
Hi! So you're looking to Mine using your Nvidia Card, don't know how to setup CUDA Miner?
The basic format for CUDA Miner's .bat file will be.
Stratum (For HTTP: Replace stratum+tcp with http):
Ex: cudaminer -H 0 -i 1 -l auto -C 2 -o stratum+tcp://xyz.yourpool.com:porthere -u username.worker -p password
What each flag does:
[-H] scrypt also has a small SHA256 component to it: 0 hashes this single threaded on the CPU. 1 to enable multithreaded hashing on the CPU. 2 offloads everything to the GPU (default)
[-i] list of flags (0 or 1) to enable interactive desktop performance on individual cards. Use this to remove lag at the cost of some hashing performance. Do not use large launch configs for devices that shall run in interactive mode - it's best to use autotune!
This setting set at 0 will cause your GPU to run at 100% and most likely will cause lag while even tabbing through your browser! Set at 1 if you're trying to use your PC while mining.
[-l] specify the kernel launch configuration per device. This replaces autotune or heuristic selection. You can pass the strings "auto" or just a kernel prefix like L or F or K or T to autotune for a specific card generation or a kernel prefix plus a lauch configuration like F28x8 if you know what kernel runs best (from a previous autotune).
[-C] list of flags (0 or 1 or 2) to enable use of the texture cache for reading from the scrypt scratchpad. 1 uses a 1D cache, whereas 2 uses a 2D texture layout. Cached operation has proven to be slightly faster than noncached operation on most GPUs.
In Depth & Getting the most out of your card:
Well, let me start off with a checklist.
Do you have the latest version of CUDA Miner?
If Yes then Move on.. If no (Or you're not sure), then go here:https://bitcointalk.org/index.php?topic=167229.0[1]
Do you have the latest drivers installed for your video card? You must have R331 or newer for latest CUDA Miner
If yes.. carry on! If not.. http://www.nvidia.com/Download/index.aspx[2]
Well then, now that that's done...
A few things you'll need to know before going on..
What video card do you have?
If you know.. Carry on. If you're not sure.. Then Install GPU-Z to find out!
Now that you know what video card you have, you'll have to find out what compute version it is using. Find your video card on this chart. (For ease, use ctrl + F on windows and then type in the # of your card)
Compute Version:
1.0
G80, G92, G92b, G94, G94b GeForce GT 420, GeForce 8800 Ultra, GeForce 8800 GTX, GeForce GT 340, GeForce GT 330, GeForce GT 320, GeForce 315, GeForce 310, GeForce 9800 GT, GeForce 9600 GT, GeForce 9400GT, Quadro FX 5600, Quadro FX 4600, Quadro Plex 2100 S4, Tesla C870, Tesla D870, Tesla S870 1.1
G86, G84, G98, G96, G96b, G94, G94b, G92, G92b GeForce G110M, GeForce 9300M GS, GeForce 9200M GS, GeForce 9100M G, GeForce 8400M GT, GeForce G105M, Quadro FX 4700 X2, Quadro FX 3700, Quadro FX 1800, Quadro FX 1700, Quadro FX 580, Quadro FX 570, Quadro FX 470, Quadro FX 380, Quadro FX 370, Quadro FX 370 Low Profile, Quadro NVS 450, Quadro NVS 420, Quadro NVS 290, Quadro NVS 295, Quadro Plex 2100 D4, Quadro FX 3800M, Quadro FX 3700M, Quadro FX 3600M, Quadro FX 2800M, Quadro FX 2700M, Quadro FX 1700M, Quadro FX 1600M, Quadro FX 770M, Quadro FX 570M, Quadro FX 370M, Quadro FX 360M, Quadro NVS 320M, Quadro NVS 160M, Quadro NVS 150M, Quadro NVS 140M, Quadro NVS 135M, Quadro NVS 130M, Quadro NVS 450, Quadro NVS 420, Quadro NVS 295
1.2
GT218, GT216, GT215 GeForce GT 240, GeForce GT 220, GeForce 210, GeForce GTS 360M, GeForce GTS 350M, GeForce GT 335M, GeForce GT 330M, GeForce GT 325M, GeForce GT 240M, GeForce G210M, GeForce 310M, GeForce 305M, Quadro FX 380 Low Profile, NVIDIA NVS 300, Quadro FX 1800M, Quadro FX 880M, Quadro FX 380M, NVIDIA NVS 300, NVS 5100M, NVS 3100M, NVS 2100M
1.3
GT200, GT200b GeForce GTX 280, GeForce GTX 275, GeForce GTX 260, Quadro FX 5800, Quadro FX 4800, Quadro FX 4800 for Mac, Quadro FX 3800, Quadro CX, Quadro Plex 2200 D2, Tesla C1060, Tesla S1070, Tesla M1060
2.0
GF100, GF110 GeForce GTX 590, GeForce GTX 580, GeForce GTX 570, GeForce GTX 480, GeForce GTX 470, GeForce GTX 465, GeForce GTX 480M, Quadro 6000, Quadro 5000, Quadro 4000, Quadro 4000 for Mac, Quadro Plex 7000, Quadro 5010M, Quadro 5000M, Tesla C2075, Tesla C2050/C2070, Tesla M2050/M2070/M2075/M2090
2.1
GF104, GF106 GF108,GF114, GF116, GF119 GeForce GTX 560 Ti, GeForce GTX 550 Ti, GeForce GTX 460, GeForce GTS 450, GeForce GTS 450, GeForce GT 640 (GDDR3), GeForce GT 630, GeForce GT 620, GeForce GT 610, GeForce GT 520, GeForce GT 440, GeForce GT 440, GeForce GT 430, GeForce GT 430*, GeForce GTX 675M, GeForce GTX 670M, GeForce GT 635M, GeForce GT 630M, GeForce GT 625M, GeForce GT 720M, GeForce GT 620M, GeForce 710M, GeForce 610M, GeForce GTX 580M, GeForce GTX 570M, GeForce GTX 560M, GeForce GT 555M, GeForce GT 550M, GeForce GT 540M, GeForce GT 525M, GeForce GT 520MX, GeForce GT 520M, GeForce GTX 485M, GeForce GTX 470M, GeForce GTX 460M, GeForce GT 445M, GeForce GT 435M, GeForce GT 420M, GeForce GT 415M, GeForce 710M, GeForce 410M, Quadro 2000, Quadro 2000D, Quadro 600, Quadro 410, Quadro 4000M, Quadro 3000M, Quadro 2000M, Quadro 1000M, NVS 5400M, NVS 5200M, NVS 4200M
3.0
GK104, GK106, GK107 GeForce GTX 770, GeForce GTX 760, GeForce GTX 690, GeForce GTX 680, GeForce GTX 670, GeForce GTX 660 Ti, GeForce GTX 660, GeForce GTX 650 Ti BOOST, GeForce GTX 650 Ti, GeForce GTX 650, GeForce GTX 780M, GeForce GTX 770M, GeForce GTX 765M, GeForce GTX 760M, GeForce GTX 680MX, GeForce GTX 680M, GeForce GTX 675MX, GeForce GTX 670MX, GeForce GTX 660M, GeForce GT 750M, GeForce GT 650M, GeForce GT 745M, GeForce GT 645M, GeForce GT 740M, GeForce GT 730M, GeForce GT 640M, GeForce GT 640M LE, GeForce GT 735M, GeForce GT 730M, Quadro K5000, Quadro K4000, Quadro K2000, Quadro K2000D, Quadro K600, Quadro K500M, Tesla K10
3.5
GK110, GK208 GeForce GTX TITAN, GeForce GTX 780, GeForce GT 640 (GDDR5), Quadro K6000, Tesla K20 '*' - OEM-only products (Thanks Wikipedia!)
Now.. Moving on and now that you know what version you have..
We now can find out what Kernel CUDA Miner is best suited to using!
Available kernel prefixes are:
L - Legacy cards (compute 1.x)
F - Fermi cards (Compute 2.x)
S - Kepler cards (currently compiled for Compute 1.2) - formerly best for Kepler
K - Kepler cards (Compute 3.0) - based on Dave Andersen's work. Now best for Kepler.
T - Titan, GTX 780 and GK208 based cards (Compute 3.5)
X - Experimental kernel. Currently requires Compute 3.5
(Copied from the CUDAMiner Readme)
For Legacy Cards you're best off using auto.
Now find the # of SM(X) units for your card here:http://en.wikipedia.org/wiki/Comparison_of_Nvidia_graphics_processing_units[4]
Fermi is limited to 16 Warps per SM Unit Kepler is limited to 32 Warps per SMX Unit.
If you're on Fermi, with The 560 Ti which has 8 SM units your .bat file will look something like: cudaminer -H 0 -i 1 -l F8x16 -C 2 -o stratum+tcp://xyz.yourpool.com:porthere -u username.worker -p password
If you're using Kepler, with the 660 (Seems to be a popular card), which has 5 SMX Units your .bat will look like: cudaminer -H 0 -i 1 -l K5x32 -C 2 -o stratum+tcp://xyz.yourpool.com:porthere -u username.worker -p password
Titan should be the same as Kepler. (Although someone else may know more on this topic..)
Ta-Da!
To get the most out of your card, you can tweak the -H and -C with 0 1 or 2. I would not recommend using -i 0 if you are trying to browse the web while using your computer, things can stutter, a lot, and annoy you.
General Mining Tips:
  1. Be sure to find a good pool of course! Try to find a PPLNS Pool with 0-1% fee. I'm not going to suggest any, I don't want to seem biased. There are many good pools! (Thanks Crazypotatoes on doges.org for suggesting this)
  2. Use GPU-Z to monitor temperatures on your card. If it gets too hot you may want to shut it down. Mining doges isn't worth it at the expense of your computer and or video card. (Crazypotatoes again)
  3. Use MSI Afterburner to increase your fan speeds. (Don't Overclock if you're not sure about what you're doing. There are many guides on this but I don't think its worth it if you're not sure what you're touching.) (Yep Crazypotatoes)
Some cards and configs:
560 Ti: -H 0 -i 1 -l F8x16 -C 1 -m 1
660: -H 0 -i 1 -l K5x32 -C 1 -m 1
670:-H 0 -i 1 -l K7x32 -C 1 -m 1
780: -H 1 -i 1 -l T9x20 -C 2 or -H 1 -i 1 -l T12x32 -c 1

Thursday, December 26, 2013

soft question - On "familiarity" (or How to avoid "going down the Math Rabbit Hole"?) - Mathematics Stack Exchange

Anyone trying to learn mathematics on his/her own has had the experience of "going down the Math Rabbit Hole". 
For example, suppose you come across the novel term vector space, and want to learn more about it. You look up various definitions, and they all refer to something called a field. So now you're off to learn what a field is, but it's the same story all over again: all the definitions you find refer to something called a group. Off to learn about what a group is. Ad infinitum. That's what I'm calling here "to go down the Math Rabbit Hole."...

Wednesday, December 18, 2013

How to: Create a BSoD-like 404 page | CatsWhoCode.com


- ooops! -
body {
background:#0000aa;
color:#ffffff;
font-family:courier;
font-size:12pt;
text-align:center;
margin:100px;
}

blink {
color:yellow;
}

.neg {
background:#fff;
color:#0000aa;
padding:2px 8px;
font-weight:bold;
}

p {
margin:30px 100px;
text-align:left;
}

a,a:hover {
color:inherit;
font:inherit;
}

.menu {
text-align:center;
margin-top:50px;
}


ERROR 404
The page is missing or never was written. You can wait and

see if it becomes available again, or you can restart your computer.

* Send us an e-mail to notify this and try it later.


* Press CTRL+ALT+DEL to restart your computer. You will

  lose unsaved information in any programs that are running.

Press any link to continue _

Microsoft urges Windows 7 users to uninstall 'Blue Screen of Death' patch - Computerworld

FWIW

How to tell HTML from HTML5 – catalint.ro


  • Try it out on Internet Explorer.
  • Did it work?
  • No?
  • It's HTML5.
lol !

Tuesday, December 17, 2013

[ANN] [MΣC] Megacoin.co.nz - Forum, Github, Website Now in 14 Languages

Yes! Of course! August 28, 2013!
That was the day I invented time-dilated difficulty gravitational wells. The black holes of difficulty formulas! I remember it vividly.
I was standing on the edge of my toilet about to upload a standard fork, the porcelain was wet, I slipped, hit my head on the sink, and when I came to I had a revelation!
A vision! A picture in my head! A picture of this!



This is what makes time-dilated difficulty formulas possible: the Kimoto Gravity Well! It's taken me nearly sixty six years and my entire family fortune to realize the vision of that day.
KGW = 1 + (0.7084 * pow((double(PastBlocksMass)/double(144)), -1.228));

Marty, we don't have much time, we must release it upon the universe today.
The future of Megacoin depends on it.

Monday, December 16, 2013

Middlecoin Usage Example

Middlecoin

This pool automatically mines the most profitable scrypt coin, automatically exchanges those coins for bitcoins, and pays out entirely in bitcoins.
There is no registration. Simply connect your scrypt miner to middlecoin.com:3333 or 8080 with your bitcoin address as your username, and any password. Payouts are automatic, and occur once a day, if your balance is greater than 0.001 BTC.

Example Usage:

cgminer --scrypt -o stratum+tcp://middlecoin.com:3333 -u 1MpfkH1vDyGrmtykodJmzBNWi81KqXa8SE -p hunter2

Nvidia exploit could turn render farms into password crackers, bitcoin miners, researchers claim | PCWorld

How it works
"...On Windows, Nvidia Mental Ray runs as a system service and listens for incoming connections on port 7520, the ReVuln researchers said. To exploit the vulnerability, an attacker just needs to send a malicious packet to the affected systems from a compromised computer on the same network, they said..."

Review: Ematic EM63 7" Android Tablet - The Digital Reader

Review: Ematic EM63 7" Android Tablet - The Digital Reader:

'via Blog this'

Jarred's Tech Blog: LTC4You: Fun with uLTC

"You've been warned. Now all of you go play off my referral link so I can earn another $0.10 for this awesome post!"

:)

Sunday, December 15, 2013

Why Bitcoin Will Never Be a Currency—in 2 Charts - Matthew O'Brien - The Atlantic

Wow, what a load of crap, misinformation, and weasel words.

Crapbytes:
"though this time central banks have at least kept prices from falling, just barely"
"there's actually a currency designed to create these kind of economic calamities"
"the virtual currency you can theoretically use to buy things online"
"bitcoins that will only grow at a low rate until 2040—and then stop"
"As point of comparison"
" it doesn't hurt the real economy"
"It's hard to see any pattern here"
"Bitcoin won't work as a currency as long as it's so deflationary"
"The only reason would be to buy or do things online that you can't buy or do something illegal."
"What Bitcoin really needs is a central bank to stabilize its value"
"they want Bitcoin to be a Ponzi scheme"
"it's just a dotcom stock"

Saturday, December 14, 2013

Bitcoin happyness.

"Money can't buy happiness, but bitcoins can." - a Protiguous platitude.

Thursday, December 12, 2013

“416d65726963612043616e20436f646520!” | Congressman Tony Cardenas

Dec 12, 2013 
Press Release

Today, U.S. Rep. Tony Cárdenas (D-San Fernando Valley) introduced the 416d65726963612043616e20436f646520 Act of 2013, also known as the America Can Code Act. This legislation would designate computer programming languages as “critical foreign languages” and provide incentives for state and local schools to teach more computer science beginning as early as Kindergarten.
Thursday, December 12, 2013

CÁRDENAS: “416d65726963612043616e20436f646520!”
(Washington, DC) -- Today, U.S. Rep. Tony Cárdenas (D-San Fernando Valley) introduced the 416d65726963612043616e20436f646520 Act of 2013, also known as the America Can Code Act. This legislation would designate computer programming languages as “critical foreign languages” and provide incentives for state and local schools to teach more computer science beginning as early as Kindergarten.
The official short title of the name is believed to be unique among Congressional legislation. “416d65726963612043616e20436f646520” is the hexadecimal code translation of “America Can Code.”
“The very name of this law demonstrates that programming is simply another language,” said Cárdenas. “Learning and communicating in a foreign language can have a tremendous impact on a student, both culturally and educationally. Computer programming creates a similar impact, while also providing a critical skill in today’s global economy.”
Cárdenas was joined in introducing the bill by original co-sponsor Rep. Mike Honda, also of California.
Cárdenas introduced the America Can Code Act after noting that the growth of computer programming jobs at nearly twice the national average rate. According to the Bureau of Labor Statistics, the median annual wage in 2010 for computer programmers was $71,380, while the median annual wage for all workers was $33,840.
By 2020, there will be an estimated 1.4 million computer programming jobs, with only 400,000 American computer science students to fill those jobs. Nine out of 10 schools in the United States do not even offer computer programming classes and in 36 states, computer coding classes do not count towards high school STEM graduation requirements.
“American students should continue to receive the understanding of other cultures that foreign language learning creates, but we should also be preparing American kids to compete in the world marketplace,” continued Cárdenas. “Millions of jobs are being created in America, and all over the globe, requiring some level of coding knowledge. Let’s get American kids ready to compete for American jobs.”
Along with redefining computer programming as a critical foreign language, the 416d65726963612043616e20436f646520 Act would create a competitive matching grant program for schools, particularly those in low-income areas, to create new ways to teach computer science and engineering, in tandem with universities and non-profits.

Tuesday, December 10, 2013

Stupid newbie question about the bitcoin nonce

Post by: anewbie on May 23, 2011, 03:24:05 AM

This is definitely a newbie question.  It has probably been answered before, but I can't find it with the searches I've done.

I have come to bitcoin with the slashdot post last week and have tried to educate myself before asking stupid questions.  I started bitcoin mining solo and after about a day and a half realized I should join a pool.

I'm using the poclbm client.

As I understand bitcoin mining (in a pool or solo), I am grabbing the hash of the previous block, possibly some transactions, my (or the pool's) address and randomly trying different nonce's to get a hash of all of that smaller than a specified value based on the current difficulty.

But here's where I am confused.  My miner (solo or pooled) using my Radeon 5770 card reports around 170 - 175 Mhashes/sec.

The nonce on block 125907 found as I began writing this was 150,035,635 (comma's added for readabilty).  If the Mhashes reported by my miner are checking blocks by playing with the nonce, that should have been found in a second.

As I've written this, block 125908 has been found with a nonce of 3,787,138,861.  At 170M/s that would have taken just under 22 seconds.

Obviously, I'm missing something.  Technically, I do realize that a block hash is the hash of a hash, but still, I do not understand what is being reported as hashes/second when trying to find a block.

Technical discussions over my head are welcome as are pointers to threads where this has already been asked.  But, in a nutshell, if the only thing that a miner program is playing with is the nonce, why is the nonce so small compared to the hashes/sec or the time to find a block?




Title: Re: Stupid newbie question about the nonce
Post by: theymos on May 23, 2011, 03:33:53 AM

The nonce is reset from time to time. With pooled mining, you ask the pool for new work when this happens. With solo mining, you modify the coinbase transaction to get a new set of hashes to try.


Title: Re: Stupid newbie question about the nonce
Post by: kjj on May 23, 2011, 03:34:50 AM

There is another one in the Merkle root.

If a miner burns through every possible nonce in the block header without success (which is most of the time), it reports that to the node, which updates the Merkle nonce and hash (it might also reconsider which transactions to include and possibly a new timestamp), and starts over.


Title: Re: Stupid newbie question about the nonce
Post by: anewbie on May 23, 2011, 03:43:55 AM

Then what is the upper limit on the nonce?  Is there one in the protocol?

On transactions, if I'm solo mining, are those being assigned to my miner, or is it picking them out of the pool of transactions on its own? 


Title: Re: Stupid newbie question about the nonce
Post by: theymos on May 23, 2011, 03:47:50 AM

The upper limit is 4294967295, but Bitcoin resets the nonce long before you reach that. The reset is based on time, I believe. Edit: Actually, it looks like the nonce does go right up to the limit before being reset. ExtraNonce is the one that is reset based on time.

On transactions, if I'm solo mining, are those being assigned to my miner, or is it picking them out of the pool of transactions on its own?  

Are you talking about transactions in blocks? Solo miners pick them according to their own rules.


Title: Re: Stupid newbie question about the nonce
Post by: anewbie on May 23, 2011, 03:52:30 AM

Thanks to both of you for the quick answers.  One final question and I'm done for the night.

Theymos talks about the node resetting the nonce. kjj talks about the node making changes in the merkle root and possibly the timestamp.  Are you both talking about the same thing?  Merkle root nonces?  I thought that a miner was playing with the nonce itself to get a block.  Is my inderstanding incorrect.

Thanks again, and I promise I'm done for the night.

I may come back with more newbie questions tomorrow, though.


Title: Re: Stupid newbie question about the nonce
Post by: Meni Rosenfeld on May 23, 2011, 04:26:32 AM

Thanks to both of you for the quick answers.  One final question and I'm done for the night.

Theymos talks about the node resetting the nonce. kjj talks about the node making changes in the merkle root and possibly the timestamp.  Are you both talking about the same thing?  Merkle root nonces?  I thought that a miner was playing with the nonce itself to get a block.  Is my inderstanding incorrect.

Thanks again, and I promise I'm done for the night.

I may come back with more newbie questions tomorrow, though.
The miner plays with the nonce to get a block, up to a point. Since nonce is a 32-bit integer which only allows for 4B values, eventually it will need to ask the server (whether locally or on a pool) for a new merkle root to work on (where things like the extra nonce have been changed).


Title: Re: Stupid newbie question about the nonce
Post by: theymos on May 23, 2011, 04:33:41 AM

A solo miner increments Nonce until it overflows. Then it increments extraNonce and resets Nonce. extraNonce is located in the coinbase transaction, so changing it alters the Merkle root. extraNonce is reset based on the time.


Title: Re: Stupid newbie question about the nonce
Post by: kjj on May 23, 2011, 04:51:56 AM

I think that a lot of the confusion comes from thinking that there is just the one true next block and everyone is trying to find the one.

That isn't how it works.  There are many blocks that could be the next one.  The difficult part is finding one out of the much huger number of blocks that aren't difficult enough.

Each node builds up a list of pending transactions, and they pick some or all of them to go into the new block.  Once they have their list of accepted transaction, they calculate the hash of a Merkle tree for that list.  One of these transactions is unique to that node too, because it is the generation transaction, and everyone gets to pick their own account for the reward.  So, even if everyone had the same rules for picking and ordering transactions, they would all be starting from different places anyway.

For many potential blocks, there is no value of the nonce that will give a hash less than the target.  When that happens, the node must alter something in the block header and try again.  The timestamp is a good candidate, since it usually takes some time to try all 2^32 nonces.  New transactions may have come in across the network that can be added to the tree too.

I could have sworn there was also a nonce in the Merkle tree calculations, but I can't find any references to it now.  Ahh, theymos found it while I was typing.  It is in the generation transaction, which changes the Merkle hash.

In a pool, the pool server will hand out unique headers to each worker/request, by using the extraNonce and rehashing the tree, to prevent duplication of work and get better odds of finding a valid block.


Title: Re: Stupid newbie question about the nonce
Post by: thedrs on May 23, 2011, 09:26:38 PM

Thanks KJJ that was very helpful for understanding how it works.
Many of the newbie tutorials explain the system in a more simple manner which makes you assume there is 1 true next block that everyone is working on.

Now, after reading you post it is clear why everyone is actually working on a different one.

Now I have to go find some info on what a Merkle tree is .... :P

A new mystery about Satoshi hidden in the Bitcoin block-chain | bitslog

Quote from the blog...
So at this point I thought about four possible reasons for the imbalance:
A. My block chain parser is completely broken. Or my PC has been hacked and someone is playing a joke on me.
B. Satoshi was mining with a hardware very different from a PC. The imbalance was due to an optimization on the hardware, such as using gray codes for counting. In fact, the missing nonce values seems roughly compatible with a kind of decimal broken gray code. But this is too extravagant to be true. And nobody would use a decimal gray code instead of a binary gray code for a binary machine. But f this is true, then it has far reaching consequences: Satoshi foresaw the advantage of FPGA/ASIC much sooner than everybody else.
C. Satoshi discovered a flaw in SHA-2 so he didn’t need to go through all 32 bit nonces, just one fourth of them. Or he just solved some equations to find the nonce which gave only those restricted solutions. This is highly improbable.
D. Satoshi  left a message fingerprinted in the nonces. A Message for us to see in a distant future.

Monday, December 9, 2013

Grace Hopper - Wikipedia, the free encyclopedia

What an amazing lady. Here's the Wikipedia highlights.

Grace Murray Hopper (December 9, 1906 – January 1, 1992) was an American computer scientist and United States Navy Rear Admiral. A pioneer in the field, she was one of the first programmers of the Harvard Mark I computer, and developed the first compiler for a computer programming language. She conceptualized the idea of machine-independent programming languages, which led to the development of COBOL, one of the first modern programming languages. She is credited with popularizing the term "debugging" for fixing computer glitches (inspired by an actual moth removed from the computer). Owing to the breadth of her accomplishments and her naval rank, she is sometimes referred to as "Amazing Grace". The U.S. Navy destroyer USS Hopper (DDG-70) is named for her, as was the Cray XE6 "Hopper" supercomputer at NERSC.


UNIVAC

In 1949, Hopper became an employee of the Eckert-Mauchly Computer Corporation as a senior mathematician and joined the team developing the UNIVAC I.[12] In the early 1950s the company was taken over by the Remington Rand corporation and it was while she was working for them that her original compiler work was done. The compiler was known as the A compiler and its first version was A-0.[15]:11
In 1952 she had an operational compiler. "Nobody believed that," she said. "I had a running compiler and nobody would touch it. They told me computers could only do arithmetic."[16]
In 1954 Hopper was named the company's first director of automatic programming, and her department released some of the first compiler-based programming languages, including MATH-MATIC and FLOW-MATIC.[12]

COBOL


Grace Murray Hopper at the UNIVAC keyboard, c. 1960
In the spring of 1959, a two-day conference known as the Conference on Data Systems Languages (CODASYL) brought together computer experts from industry and government. Hopper served as the technical consultant to the committee, and many of her former employees served on the short-term committee that defined the new language COBOL (an acronym for COmmon Business-OrientedLanguage). The new language extended Hopper's FLOW-MATIC language with some ideas from the IBM equivalent, COMTRAN. Hopper's belief that programs should be written in a language that was close to English rather than in machine code or languages close to machine code (such as assembly language) was captured in the new business language, and COBOL would go on to be the most ubiquitous business language to date.[17]
From 1967 to 1977, Hopper served as the director of the Navy Programming Languages Group in the Navy's Office of Information Systems Planning and was promoted to the rank of captain in 1973.[14] She developed validation software for COBOL and its compiler as part of a COBOL standardization program for the entire Navy.

Anecdotes


Photo of "first computer bug"
Throughout much of her later career, Grace Hopper was much in demand as a speaker at various computer-related events. She was well known for her lively and irreverent speaking style, as well as a rich treasury of early war stories. She also received the nickname "Grandma COBOL".
  • Grace Hopper is famous for her nanoseconds visual aid. People (such as generals and admirals) used to ask her why satellite communication took so long. She started handing out pieces of wire which were just under one foot long (11.80 inches), which is the distance that light travels in one nanosecond. She gave these pieces of wire the metonym "nanoseconds."[22] She was careful to tell her audience that the length of her nanoseconds was actually the maximum speed the signals would travel in a vacuum, and that signals would travel more slowly through the actual wires that were her teaching aids. Later she used the same pieces of wire to illustrate why computers had to be small to be fast. At many of her talks and visits, she handed out "nanoseconds" to everyone in the audience, contrasting them with a coil of wire nearly a thousand feet long, representing a microsecond. Later, while giving these lectures while working for DEC, she passed out packets of pepper which she called picoseconds.
Jay Elliot described Grace Hopper as appearing to be "'all Navy', but when you reach inside, you find a 'Pirate' dying to be released".[40]