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21  Bitcoin / Hardware / Sydney - Klondike assembly EOI on: May 20, 2013, 08:44:39 AM

Klondike assembly EOI

I am looking to get around 37 Klondike boards professionally assembled in Sydney. At this stage I will be waiting on the final PCB design and BOM so I can get quotes.

If you are interested in adding to my possible order please post. The larger the run the cheaper it is.

I used to work in the smd assembly industry, admittedly that was a long time ago but it does mean I am comfortable getting this done.
22  Bitcoin / Bitcoin Discussion / Re: Department of Homeland Security on: May 18, 2013, 04:44:42 AM
for every action there is a reaction.

i wonder what role the Chinese will play in this.  there have been hints that they might actually support the Bitcoin concept.  is DHS sending a message?

if so, i'm sure a response will be forthcoming in some form or manner.

The Cold Bitcoin War. More hashrate!

Couldn't the US government hypothetically run existing supercomputers to mine all the remaining Bitcoins and just destroy it that way? For the amount of money it takes to file all the legal paperwork and run the DHS for a week, they could contract an ASIC to be built which could mine the remaining Bitcoins in a very short period of time. Or am I wrong about this?

yep, you're wrong:

Based on 82Th and 50Gh@$1200(Avalon)x1000units=50Th right now anyone can break bitcoin with a 51% attack for around $1.2m.

Add to that some strategic targeting of mining pools etc for when the attack goes in: blocking of IP addresses/raids to confiscate mining equipment(you pirated a song, have your stuff back a week later)/cloak and dagger - oh no your house lost electricity cause someone stole the fuses.

23  Bitcoin / Hardware / Re: [Work in progess] Burnins Avalon Chip to mining board service on: May 18, 2013, 02:59:57 AM

I would like the option to water cool, mainly to cut down on noise and heat inside the room.
I have come up with a very simple DIY system that should be bullet proof and easy for anyone to make.
However to make it possible the board layout would need to conform to some standard sizes.

The system I propose is an aluminum rectangle tube capped at both ends with a hose fitting welded at each end.
The boards to be held in place with 2 x square u bolts. The welded hose fittings and capping can be done by your local welder.

Most places stock the tube in 6 meter lengths so if boards are say 150 wide you could fit 40 boards on the one heat sink (prob not practical to do that long).  As you can have the tube any length it will be flexible solution.

I guess the feasibility of this idea depends on if on if burnin is willing to have a predetermined distance and size of mounting holes to suit a standard tube/u bolt configuration.

24  Other / CPU/GPU Bitcoin mining hardware / Re: HELP: Replacing SMD Capacitors on a Radeon 7970 on: September 01, 2012, 06:49:51 PM
I would say it is unlikely you can repair this without access to the circuit diagram or parts.

I can offer some suggestions based on probability.

The caps you have selected do not burn up. When they blow they go open circuit and you cannot tell by looking at them. Seeing similar caps scattered about the board I would say they are filter caps for the power rail. If this is the case it means that the value is not critical so 100nf should be ok. Also if they are filter caps then a power rail is very near.

My best guess based on the limited information is that a semiconductor has blown and shorted out the power rail and I think the power rail heated up and cooked where it was the thinnest and that track is inside the multi layer board so you cannot see it.

If this is the case you have two problems. 1) repairing the track, if it is open circuit you cannot trace it out so you will need a good board to test or a circuit diagram, once you know the route you can link with a wire. 2) you need to locate and replace the component that blew the track in the first place and that could be anywhere on the board....... this is of course if it is a blown track in the first place

All I can tell you for sure is it is impossible for those caps to burn a board. You would have to go high voltage (for their rating)  and the worst I have seen them do is crack with a little pop and if that much of a high volt event happened the rest of the board would be a smoking ruin.
25  Bitcoin / Bitcoin Discussion / Re: Win 100 BTC by becoming the first Satoshi Superstar! on: April 05, 2012, 03:29:51 AM
I nominate astana for an entertaining contestant.

Plus if you are still short he has a few dozen alt personalities you can choose from as well Cheesy

I was thinking the exact same thing, so I conducted a little bio cross referencing. Get out of my head, Defkin.


I still nominate astana and one of his alts for last two spots Cheesy
26  Bitcoin / Hardware / Re: 1 BTC bounty --- What is the best FPGA unit to buy? on: April 05, 2012, 03:25:39 AM
You have not really given enough information for me to suggest a product.
Do you pay much for power, how many do you want to buy, would cooling and power supply be an issue if you planned on a large number of BFL. Are you looking short or long term?

For me open source, power consumption along with a planned long term operation sold me on the Icarus and looking towards the Lancelot. If I was living in a cold climate next door to a hydro power station I would be shopping for GPUs still.

Factors to consider:

  • Bulk buy options
  • Warranty
  • Cost/MH
  • Watts/MH
  • Software, a concern with propitiatory systems and third party software
  • Open or propitiatory
  • Lead time (less than 6 weeks)
  • Customer support
  • Upcoming products for example Lancelot is coming out in May and there is rumor of a new product any day now that is supposedly going to beat the BFL (not holding my breath but then again I didn't think BFL was for real either)

27  Economy / Economics / Re: Billionaires hate Bitcoin. on: March 29, 2012, 06:53:23 AM
Why would they want to invest in something that could end their hold on cheap debt and a controllable monetary supply?

It would just be eliminating their power.

I doubt it. If a billionaire had a mild dislike of bitcoin they could destroy it with pocket change.

12T/H at $1 M/H = $1.2m for a 51% attack. (if my math is right...)
If it is planned well they could turn around and sell the equipment and make a profit.

If I was doing this I would bulk purchase high-end video cards, carry out the attack, value add, reship and triple  the initial investment.
28  Economy / Trading Discussion / Re: Crypto X Change New Fee Structure Coming Shortly on: March 24, 2012, 02:16:48 PM
That card is little expensive to use and maintain.

^ understatement
29  Bitcoin / Hardware / Re: Icarus bulk orders. Who's interested? on: March 23, 2012, 11:45:41 AM
Has anyone quoted getting the boards made locally?
It is open source after all, all the files needed are on Git so you can email the zip file to get the quote.
Not only that they can probably buy the components cheaper than you can.

You can also most likely arrange for the pcb maker to ship to different addresses. Have everyone pay directly so there is no trust issue.
30  Other / Politics & Society / Re: In a perfect world we wouldn't need Bitcoin on: March 22, 2012, 12:30:53 PM
In a perfect world I would be so rich all the money in the bitcion network would be like spare change to me. So i voted it would not be needed, at least not by me Cheesy
31  Other / Politics & Society / Re: a trivial change in language that would certainly cause world peace on: March 22, 2012, 12:27:02 PM
So does this mean for example a WTO member can nerve gas a crowd of annoying protesters and to offset donate food to the staving kids in Africa and all is good? Working the ratio to food versus victims they could get a positive HUMANLIVES balance and improve traffic congestion where they have meetings.
32  Economy / Services / Re: Single? I can find someone for you who is worth a damn. on: March 22, 2012, 11:59:47 AM
Where do you operate? I'm a mediocre looking middle aged middle eastern caucasian male looking for a beautiful young girl with money who would help me leave back my wife and kids, move to the caribbean and forget that this catastrophe ever happened. Don't worry, she'll pay you too.

Make that same for me Cheesy
33  Bitcoin / Wallet software / Re: android wallet to webcam client? on: March 22, 2012, 11:40:15 AM
Perhaps this info will help:

Bitcoin Wallet for Android can export/import transactions via QR code. This means you can use an isolated phone for signing, and use a second phone for transmitting into the P2P network.

so to sign the transaction the 2nd phone will never be connected to net and the only interaction is needs to to see and display the qr codes?

But won't the private keys still be on the 1st phone, the one that connects to the net? So if the hacker steals the private keys off the 1st phone what need would they have to compromise the 2nd?
34  Bitcoin / Wallet software / Re: android wallet to webcam client? on: March 22, 2012, 11:33:16 AM
Thanks for the replies.

The concept I am looking for is a portable, physically isolated device that I can verify with my own two eyes data that goes in and out.

You hear in the news every day about hacks, data stolen. Even in this community people have had BTC stolen through hacks. NASA and Oak Ridge cannot keep their data safe. Physically isolated systems in nuclear reactors are getting targeted worms through usb sticks......the list goes on.

I understand that the limitation on the web cam idea is a hardware/driver problem. As a compromise would it be feasible to have the android device connect via head phone and use audio? It would be extremely unlikely there is an existing vulnerability in the OS and other software that could be exploited by this communication method.

Have wallet send {receiving address - amount - private key to use} via audio. Android program receives data {display incoming data [user ack] generate payment hash - send to audio}.

You would need a patch audio cable..... but short of making a specific hardware platform I am out of idea atm.

This way I could go to an internet cafe and use a web based wallet and be still be secure by jacking into the headphone socket?
35  Other / Politics & Society / Re: The Pirate Bay to Fly 'Server Drones' to Avoid Law Enforcement - Bitcoin drones? on: March 22, 2012, 09:37:18 AM
We might be able to buy Sealand for BTC?
36  Economy / Services / Re: Know HVAC?? Need your help on: March 18, 2012, 12:34:37 PM

I've thought about the positive pressure. Is there any way to measure that?  I can try to take a guess but there are leaks of air from the roll up door and other places, so I can't be too precise.

When you open the door a crack standing outside you will feel the air blow out through the gap. If you want to measure it use a magnehelic gauge.

I would be blowing air up through the racks from underneath. Have the intake low and the exhaust on the ceiling.

Considering in the number of fans you have it may be more cost effective power-wise to install a small split system. 4-5 standard fans prob equal a 1.5kw split system.
37  Bitcoin / Wallet software / Re: android wallet to webcam client? on: March 18, 2012, 06:45:28 AM
this is totally possible, except that the return of the signed transaction to you computer can not be stored inside a single qr code most of the time. QR codes provide only limited storage, and transactions can be multiple kilobytes in size. this might be possible to circumvent using multiple qr codes in a sequence though.

This is good to know, the idea of having my private keys never in contact with the internet has a lot of appeal to me. This way assuming my wallet and PC has been hacked and hopelessly compromised my BTC is still safe? I cannot keep my PC safe between OS day one flaws and clever hackers but I know I can keep a pad or old phone off the net.

Is there any way the transaction data can be messed with once it has been sent back (via 2 x qr codes) to the PC besides just preventing the transaction?

If there is a solid foundation to the concept and interest maybe I can start a bounty on it. I am sure many people have old smartphones etc that can be used for the purpose.

38  Bitcoin / Bitcoin Discussion / Re: Win 100 BTC by becoming the first Satoshi Superstar! on: March 17, 2012, 05:02:36 PM
I nominate astana for an entertaining contestant.

Plus if you are still short he has a few dozen alt personalities you can choose from as well Cheesy
39  Bitcoin / Hardware / Re: Water Cooling for large FPGA mining cluster (hundreds of FPGAs) on: March 15, 2012, 10:56:33 AM
I have been tossing the idea of FPGA water cooling around a bit. Based on the Icarus (only type i have).

I think conventional water blocks and pipe are out, too many parts, balancing etc

My thinking at this point is a 'G' clamp type of setup. The back of the clamp is a metal square tube about 100mm x 50mm that the water runs though. The top of the clamp would be 10mm flat bar that covers the top of both chips and is welded at right angle to the tube. The clamp would be a nut welded to a rod also at right angle to the tube allowing enough room for the board to slide in between rod/nut and flat bar. Use a bolt in the nut to tighten a square of flat bar and thermal pad to secure contact with the underside pushing the chips against the flat bar on top.

In this way a 1m length of tube with a clamp every 10cm could host 20 boards (10 each side) and would be quick to fabricate without the messy water hoses and connections eliminating most of the potential leaks.

At this stage I don't have enough boards for heat to be an issue so am not planning on making one anytime soon.

40  Bitcoin / Mining / Re: My theory of shares by volume vs. speed on: March 15, 2012, 09:18:17 AM
Is it the theory that a card that is 10x faster can get a share or two in before the LP as opposed to 10 cards equaling the same hash rate due to the longer time required for the slower cards to generate a share thus missing the cutoff?

If this is the case it is also possible for the 10 cards to pop in up to 10 shares due to luck that would be impossible for the faster card to do because it is not developing them in parallel.

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