(This is all from memory at the moment as I don't have access to that computer right now, but will try to get it again in a few days)

Got hold of a family member's laptop. Had to wipe the Windows system partition and reinstall Win7 plus all the programs, I'm sure we've all been there.

Reinstalled electrum, the latest version, 2.9.3.

On opening it, was expecting to be told to create a new default wallet.

Instead I gazed upon a wallet that was neither mine, nor that relative's (I have theirs on a separate USB stick). It had over 13 BTC on it!
Naturally I first wondered if it was spendable (I'm only human) but no, it's seedless. It has transactions going back to June 2011 and up to just recently. There are several for 0.1 or 0.01 etc, and quite a few for 0.0000543 which IIRC was/is the minimum relay fee for the core client.

Can someone explain this behaviour? Is there some kind of 'test' wallet that electrum installs if it has nothing else to go on?

http://www.bbc.co.uk/news/technology-36168863

Thoughts? Where's the beef (i.e. messages signed with early block private keys)?

ETA: well the article claims such keys have been provided... I guess I'll wait until somebody somewhere actually publishes the signatures.

Running core 0.10.2 here - just on and off - to get hold of the whole blockchain. Still ~42 weeks behind. Anyway I'm trawling through the blk00xxx.dat files with a python script, and I find that part way into my blk00065.dat, there's a long string of zeroes. 249209 bytes to be precise. They start just after the end of a previous block, where my python script is obviously expecting to see 0xF9BEB4D9. After them, I do indeed get the magic bytes and it appears the blockdata resumes as normal.

Bitcoin Core doesn't seem to mind, so I presume this is expected behaviour. Is there any reason for it? Should I expect more 'deserts' later on in the blockfiles? Should I be aware of any other 'surprises', along the lines of expecting to see magic bytes but instead seeing something else?

(Oh and the answer to all 'why?' enquiries is: for fun. No, I don't get out much.)

Hi all. Though I use electrum for all my wallet needs, I use bitcoin-qt to have a local copy of the blockchain. A few days ago it told me something about a need to reindex, or a corrupt database, or something... can't remember.

Anyway since then I have repeatedly tried to download the blockchain from scratch and it cannot proceed past four years ago. I have now completely removed and reinstalled bitcoin-qt running under Ubuntu-12.04, and I still get the same problem. I try downloading from scratch, it goes okay until I get to about 4 years out-of-sync. Then bitcoin-qt tells me there was a fatal internal error. Trying to run it subsequently it keeps mentioning a segmentation fault. All I can do is delete the whole of ~/.bitcoin and... round we go again.

Any ideas? There's still 60GB of space on the hd partition.

ETA: in case it's important, the software tells me it's "Bitcoin Core version v0.10.1.0-gd8ac901 (32-bit)" and I installed it using the standard Ubuntu apt-get way of doing things.

What the title says. I gather I should probably be using one of the options "Create Transaction" or "Load Transaction" (what's the difference anyway?) in the Tools menu, but I haven't found anywhere that explains what I'm supposed to put in the file.

ETA: oh, never mind: https://bitcointalk.org/index.php?topic=451707.0
 

http://explosm.net/comics/3479/

Either this is a serious security issue or I've been badly misunderstanding what a 'seedless' wallet really is all this time.

In all my seedless wallets, I can right-click an address in the 'receiving' tab, select the 'Private key' menu option, and... it tells me the private key for that address, in wallet import format. Should it really be able to do that? I thought 'seedless' meant the same thing as 'watching only' which meant 'you can't spend from any of these addresses with this wallet because it doesn't have any of the private keys'?

Link: http://www.cracked.com/quick-fixes/4-reasons-bitcoin-hoarders-are-screwed/

I read Cracked for the lolz, not in the expectation of accurate reporting or wise counsel. So I'm not too incensed by the article. But it is rather lazy.

Point #4 (working backwards like they do) is irrelevant to anyone with half a brain. I'm very happy to brag, fate be damned, that no one is EVER going to steal my bitcoins. It's NOT GOING TO HAPPEN. But yeah, if you don't know what you're doing (hmm I'll keep 'em all on MtGox  ) you'd better not hoard any.

Point #3 has of course been done to death over the years. It's ghash NOW but it was Deepbit a long time ago, then BTC Guild, then ASICminer, then BTC Guild again, now it's kind of ghash and BTC guild combined. And they all know it's in their interests not to get 51% (or if they temporarily do, not to do mean things to the network with it)

Point #2 - well, yeah. So what?

Point #1 - it's as anonymous as you're willing to learn how to make it, just like, re #4, It's as safe as you're willing to learn how to make it. And this actually ties in to point #2. If you really consider paying taxes as the worst thing in the world, you have the means to evade them if you take your security and anonymity seriously. For myself, I'll be happy to use all the tried and tested methods that fall under the term 'avoidance' (legal yay!) rather than 'evasion' (legal boo!). In particular, I'll spend BTC rather than fiat whenever it is possible (and I have no more fiat left), and when it isn't, I'll convert BTC to fiat in as small quantities as possible. Not likely to go over CGT allowance there I reckon.

The perennial accusation against Bitcoin is that it's 'not backed by anything'. Fiat money is backed by the government, and I would say that Bitcoin is backed by cryptography. But that's only because I've formed an 'implicit definition' of that word - I hear how other people use it.

But is there an explicit definition, and if so what is it? If I think that X is a good thing because "X is backed by Y", what am I actually saying?

If this is the sort of question that's easily answered in Econ 101, please provide a link - I've never learned any economics formally.

UPDATE: found out the real culprit, ignore the struckout blather below.

You get a different set of private key/address pairs, depending on whether or not you specify the hex digits a-f as 'a-f' or 'A-F'!
It would appear that electrum uses the lowercase version internally. If you type the lowercase hex key, or the 12-word passphrase, electrum converts flawlessly between the two and generates the 'correct' set of keys. But if you use the uppercase-hex version, it generates a different set of keys. (but converts to the SAME 12-word passphrase)

I don't really understand why this should be. Surely the wallet generation algorithm takes as its seed, the 128 bits that the hex string is supposed to symbolise to humans, NOT the 256 bit string that would be the literal conversion of the ascii hex string?

In any case I think you should either put a warning on to tell people the hex string must be lowercase, or better still, handle the conversion properly with electrum. By the way, you ARE using the 'real' 128 bits, and not the 'fake' 256 bits of the ascii hex string as a seed, yes?



Subject says it all really. I get one bunch of keys if I type the 12 word phrase in, but a completely different bunch if I type the hex digits. And when I check what electrum thinks the wallet seed is supposed to be, it gives me the same 12 word bunch in both cases!

(Electrum does not tell me the hex version. y u no do this?)

I get the 'correct' wallet (i.e. the one with ALL MY MONEY in it) from typing in the 12 word phrase. Could this be something to do with the 'master public key'? What the hell is that anyway? Is it written up somewhere?

It means having:

- A brainwallet
- An outstanding bet on BetsOfBitcoin
- A BFL order
- ASICMINER.PT shares
- Some lending on BTCjam
- A modest GPU mining rig

 

Hi all. In my continuing efforts to track down why I just can't leave my goddamn miners alone for more than a day without one or more of them packing up, I've come to realise that the mobos are about the only variable left.

One of my rigs has some cheap-ass motherboard, the brand/model of which I forget at the mo. That rig generally runs for a week or more at a time, and if it crashes, it generally manages to reboot automatically and successfully, and carry on. The other two rigs each have the Asus Crosshair V Formula motherboard. The boards cost me £170 each, I bought them as the cheapest I could find with four full-length PCIe slots. It's these two rigs that just can't effing stay up, and I want you to tell me why not!

These boards seem to be designed for hardcore gamers, and they have a whole lotta bios options for overclocking. I don't know what any of those mean. I have reset all the bios options to the factory default, except for the one I need to change for BAMT's sake - something about making a USB stick get treated like a hard disk drive. Each mobo has an 'overclock' button and for some reason, that button needs to be switched ON or the rig cannot boot up at all.

Can anyone shed light on what's up? Preferably other peeps who have this actual board?

I have 3 rigs running BAMT, each with a wireless NIC, and one wireless ADSL modem/router combo to feed them all data and waste my life on my laptop. These rigs have been a real pain since I set them up, it's a lucky day when none of them need a manual reset. There seem to be a number of different faults coming up, but here I'd like to focus on two.

When a rig boots up and starts mining, all is (usually) well. The rig sees my router and communicates with it. When I type iwconfig, it shows the router's essid.

Then, a few hours later, my pool shows me the rig hasn't submitted a share for half an hour or whatever. I can't ssh into it from my laptop, nor see things on the web status thing. So I go downstairs and plug a monitor in, bring up a terminal, iwconfig, and... now there's no bloody essid! What happened? This kind of thing only happens to one rig at a time.

The second problem affects all of them. The router drops its connection, for whatever reason. So I reboot it. The connection is reestablished. At least as far as my laptop is concerned. But the miners do not resume mining. Why not? Why can they not see that we're back online and they need to get back to work?

All help gratefully received!

I paid the princely sum of £309.46 for this 5970 card. That includes a f king customs charge of £25.37. Delivered today. I have a ragamuffin rig with three 5970's and a well-to-do rig with so far only one working 5970, but room for three more.

When I put the new card into my fancy rig with the fancy mobo and fancy psu, the fans spin for a fraction of a second before everything goes dead. If I switch off the PSU for a while, then try again, same thing happens.

So I thought I'd swap out a card from my other rig, the one from the wrong sort of neighbourhood. I put this new 5970 in there, and switch on. Hey, it keeps going! Nothing's cutting out. That sounds promising, yes?

Well I instantly realised I'd better keep my nose on red alert, and sure enough, a few seconds later, the pungent smell of burning plastic. Yanked the power cord out sharpish and no mistake. Examining the 16x-16x riser cable shows that the pins supplying +3.3V, all of them and only them, look and smell burny. Better not use that cable again.

I don't mind about the cable, it was cheap and I have more... but what exactly is wrong with the card, and is it something I could fix with the loan of someone else's brain?

ETA: should add that with a mug of hot cocoa and some soothing trance music, both rigs have recovered fully from their abuse.

So I can understand a GPU running for months without a problem. And I can understand setting the engine clock to 1200MHz and the GPU telling me to f   k off as soon as I start mining. What I don't get is the pattern I observe when I'm testing out how much juice I can get out of one, and it runs for nine hours, or even nineteen, and then hangs up.

Hash #1: I don't like the speed you've got me running at, but I'll do this quietly and not say anything about it.
Hash #2: Here you go.
Hash #3: Here you go.
...
Hash #6,704,333,152: Here you go.
Hash #6,704,333,153: Here you go.
Hash #6,704,333,154: Here you go.
...
Hash #24,897,634,216,605: Here you go.
Hash #24,897,634,216,606: Here you go.
Hash #24,897,634,216,607: OH MY GOD PANIC DIE BLAAAAAAAAAAAAARGH.

What the hell? I'm sure it can't be the GPU temperature, as that never goes more than the mid-70s.

So, having done a bit of research over the last coupla months, I'm gonna make me a sweet miner. I've ordered a mobo with 4 PCIe x16's, it'll have risers, a 5970 on the end of each (delivered by the 5970 fairy), and all juiced up with a 1250W 80+ Gold PSU. Shitty CPU, cheapest ram, basic NIC and a BAMT stick, phoenix and phatk2. Oh yes, I know my onions.

This post is not about that miner.

This post is about the cheap-ass £30 mobo I bought back in October when I'd just learned what a bitcoin was. I have had it running 2 5970's. I am going to give it a third. But I want to make sure I sew the pieces together properly.

It has two PCI slots, a PCIe x1 and a PCIe x16. The PCIe x16 has a riser and a 5970. That seems fine.

The PCIe x1 has a x1 to x16 riser with the other 5970 on it. That also seems fine. But could someone confirm for me that that's all OK? There's no power issues there, right? A x16 slot can supply 75W of power, but I dunno about a x1 slot.

Then there's the PCI slots. One of those has the network card. The other one is free... but not for long. My plan is to stick a PCI-PCIe16 adapter in there, like this one: http://www.virtuavia.eu/shop/pci-32-bits-1-x-pci-express-adapter-.html . Then have a x16 riser coming out of that, then stick the third 5970 (which I already have) on the end. Is there going to be a power issue here? The 5970 will get 225W fair and square from the 6-pin and 8-pin cables to the PSU. How much will it draw through the PCI slot? How much CAN it draw from the PCI slot? What will happen to the card if it can't get enough power? What will happen to the mobo if the card draws too much power? If one of these two misfortunes is to occur, how do I know which one it'll be?

Thanks for reading this far!

Over the last couple of months I have bought 4 used 5970s off Ebay, from different vendors, and I'm planning to get 3 more. 3 of the 4 have been fine, but the last one... grr.

It's an XFX Black edition if that makes any difference. The vendor mentioned there was a hairline crack in the backplate. There is, but I don't think it's causing the problem. More worrying was that I could see a couple of patches of white goo inside the card, just behind the backplate. They remind me very much of what I saw in a PSU that I apparently blew up.

If I try to set the card mining at any decent speed it packs up... the happy green light by one of the GPUs gets replaced by an angry red light near the fan.
When I set the clock speeds VERY low (mem and core both around 100 Mhz) it can mine, but as slowly as you'd expect. Looking at the GPU temps with atitweak, I can see that within seconds of starting to mine, the reported temperature rises rapidly, reaching maybe 100C over 30 seconds (and this is with the *shitty* clock speeds). This is despite the fan going at 100% and is the same for both GPUs. Running either GPU separately still gets it going at 100C and the other GPU, which is idle, gets to around 70C.

What's going on? Are the temperature sensors merely defective? But they do show the rapid cooling when I stop mining. So I think that somehow the heat is getting trapped in the GPUs and not being dissipated. Are the white goo blobs to blame? What are they and can I fix this?

Pics of the goo hopefully to follow soon.