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October 04, 2015, 07:31:24 AM *
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1  Bitcoin / Bitcoin Discussion / Re: BurtW arrested (update: charges dropped!) on: September 29, 2015, 02:05:17 AM
There have been a number of instances of beverage containers marked redeemable, taken in semis from one state where there is no redemption program, to a state with one. In other words, no deposit was paid in the state of origin. This could be remedied if the beverage containers were labeled based on the state they were to be sold in, but that's probably too much of a burden (not that gives a shit about causing any extra burden whatsoever on businesses). Also, saw this at a recycling center recently:
Thanks for the explanation.

So this situation in California is somewhat similar to the historical cross-border empty beer bottles trade between East and West Germany. Enterprising German kids would buy beers in East Germany, drink it, wash the bottles to remove East German labels, affix some torn/fake West German paper labels and redeem the bottle deposit in the West. The arbitrage would not only pay for endless beer supply but also cover the fuel required to drive cross-border twice.

Germans took care of this crime by dismantling The Wall. I don't know what Californians will have to do.
2  Bitcoin / Bitcoin Discussion / Re: BurtW arrested (update: charges dropped!) on: September 28, 2015, 04:27:01 PM
I wonder how this current Bitcoin legal situation compares to how the regulation of pawnbrokers and swap-meets evolved in the USA. I can't even find out if the pawnbrokers are regulated federally or locally by the states/counties/municipalities.

I've drawn a blank in my circle of friends with legal education.

I couldn't find anything sensible on nor on , the top two results from the search engine.

Edit: I've found something on Wikipedia (copied from Encyclopedia Britannica) under . It seems that explicit licensing under common law started in 1785, so in effect USA imported their laws from UK.

On the related note about "martial law in the United States": not long ago I returned about 24 empty beer bottles to claim the deposit. I didn't have to sign anything to receive money, but I've noticed that most people (who were returning much larger quantities) had to sign something. Does anyone know what kind of fraud could be perpetrated on the recyclers?

3  Bitcoin / Hardware / Re: [ANN] Spondoolies-Tech - carrier grade, data center ready mining rigs on: September 25, 2015, 05:59:34 PM
No, I just wouldn't make the assumption in general.  Very few BGAs I've seen have had some thought put into ease of routing it out. Many of those are assumed to go onto 6+ layer boards with blind vias the norm, not the exception, and the internals instead designed to make life easier at the silicon level.

iirc, the RockerBox was similar in layout to the Minion chip I linked to - i.e. alternating gnd/pwr for most of the chip and i/o concentrated at one edge - just with fewer balls.  It's not entirely bad, but I can understand why e.g. sidehack would rather not go near it.  Still, that's a lot more 'intelligent' than some of the intel stuff that is a semi-random mess with two different ball pitches in die shadow / skirt .. at least for those needing to plunk it down on a board.
This checkerboard pattern is not "making life easier at the silicon level". It is a symptom of using completely invalid approximate model of parasitic components and then using those approximated, but not really existing, parasitics as an additional power decoupling filter.

It seems like despite the claims of "full custom" Spondoolies is still using only a very approximate all-digital low-power models. They are essentially invalid because they are used outside of their range of validity (in terms of self-induced noise and dissipated power).

I'm not sure if I understood your 2nd paragraph. It seems like you think I proposed using two different pad pitches: one denser for the chip and one coarser for the board. What I intended to convey is using the same pad pitch on both chips and board.  The power traces are bundled in the way similar to .

The bundling and spacing is wider to so that simple faults like shorting two neighboring pads doesn't create board-level and circuit-level fault.

I'm not up to speed with the most recent digital EDA tools, but I don't believe that their low-power all-digital tools can properly model the skin-effect and long-transmission-line-effect for those types of pad and board layouts. To get accurate models one has to drop to the all-analog or nearly-all-analog modeling.

4  Bitcoin / Hardware / Re: [ANN] Spondoolies-Tech - carrier grade, data center ready mining rigs on: September 25, 2015, 05:34:41 PM
Am I criminally optimistic Jew ?
How would I know? It is not for me to judge, I'm just an observer.

In the past, in the case I was sort-of-involved by being the company insider, it took around 7 years from the time certain executive made certain sales projections to that executive being sentenced for breach of the fiduciary duty. Of that 7 years the company was defunct/bankrupt for 5-6 years.

The difference between the sentenced executive and the other one who weren't charged was, as far as I could tell, only that he was the most secretive whereas the other always kept giving interviews and co-authoring published scientific papers.

The way the lawyers explained it to me is that there's wide gray area between investing and gambling. Obviously there's no such actual charge as "criminal optimism", but it is an useful shorthand to how the courts decide in similar cases.
5  Bitcoin / Hardware / Re: [ANN] Spondoolies-Tech - carrier grade, data center ready mining rigs on: September 25, 2015, 04:06:32 PM
All this of course assumes an intelligent designer.
I would never make such an assumption.
This is very grim when we can't assume an intelligent designer even in the Spondoolies' thread.

I was sort of OK, when the Chinese mining chip vendors weren't able to hire or contract the actual design talent. China is undergoing a period of extra-fast growth and there are plenty of competing opportunities there.

But I'm getting scared if a Jewish company can't find an intelligent Jew to stay with them even part-time to tell the ins-and-outs of hardware engineering.

What does it mean for Bitcoin if the really intelligent Jews avoid it and the only Jews that deal with Bitcoin are the ones that skew towards being criminally optimistic?
6  Bitcoin / Hardware / Re: GekkoScience BM1384 Project Development Discussion on: September 24, 2015, 10:41:50 PM
Early Cisco IOS's were heavily based on Linux.
When NT was released NT had dynamic memory allocation/deallocation, Linux did not.
Crazy stuff! Where did you get such information?
7  Bitcoin / Hardware / Re: [ANN] Spondoolies-Tech - carrier grade, data center ready mining rigs on: September 24, 2015, 12:21:12 AM
This is a CSP which typically means there'll be a BGA or LGA style physical interface to the actual chip, in which case the pitch/ball count is what matters the most.  Even at 0.5mm pitch and unpopulated areas, that's a lot of balls, many of which difficult to inspect.  Would be unnecessary hit/miss soldering jobs, or having to choose to outsource board population for just that part.
The soldering difficulty is way overstated for the mining chips. It is true that the BGA packages have hundreds of contact points. But with a halfway-intelligent design those BGA pads can be easily made quadruple-redundant with double spacing of no-contact pads in-between.

Then the expensive precision placing & soldering & x-ray testing will not be necessary.

All this of course assumes an intelligent designer.

Bad pinout example:
Good pinout example:
8  Bitcoin / Hardware / Re: Bitcoin Core calculator, can it be home brewed? on: September 17, 2015, 09:07:58 PM
All I'mma say is, steam locomotives are badass. Sure they don't have 3000HP 16-cylinder diesel engines with 700CID per cylinder, but if I were a train driver I'd want to know how to run them too. Punching logic into a capture and flashing it to an FPGA is really cool, but patching together PDIPs to do the same thing is a different kind of cool.
I have nothing against steam locomotives. But there are two kinds of steam locomotive engineers:

1) the ones that only know how to shovel the coal from the back tender to the front boiler;

2) the ones that could explain to you various kinds of and why is the most popular.

As a kid I was fascinated by the steam locomotives and had a good fortune of meeting the 2nd kind of railroad engineer.

It is the key difference between education and training and it has been known for a long time:

A novice was trying to fix a broken Lisp machine by turning the power off and on.
Knight, seeing what the student was doing, spoke sternly: "You cannot fix a machine by just power-cycling it with no understanding of what is going wrong."
Knight turned the machine off and on.
The machine worked.
9  Bitcoin / Hardware / Re: Bitcoin Core calculator, can it be home brewed? on: September 17, 2015, 08:05:30 PM
Thanks for your input on the logic of SHA256. Like I said, I haven't looked at it at all so I have no idea yet what the complexity is. AJR's fixin' to build this thing, I'm mostly just watching because I already have enough on my plate to keep me busy 80 hours a week.

If I were building it, I'd build it to interface to a computer built in the last 10 or 15 years. I have some machines with PCI-X, not sure I have anything with ISA anymore though. I know parallel is disappearing, which is why I had to whip out a Promise card to tie my optical drives in when I had to do a motherboard upgrade last year. It's the very fact that parallel busses are disappearing that I figured working a common serial bus into something usable by the logic would make it a heck of a lot easier to interface to a machine that anyone would still be running.
It is EISA not ISA. The interface to the SHA-256 miner really wants to be 32-bit wide. As far as I know those are still being made as "passive backplane" industrial control computers. If somebody is dead-set on the TTL implementation EISA is the way to go because of sufficiently high IO voltages and sufficiently low IO clock speeds. I would think that meeting the PCI-X timing requirements using raw TTL logic may require some significant skills.

For the sane educational project probably the best kit would be something like which is Xilinx Zynq (ARM Cortex A9 & Kintex 7Artix 7?  FPGA on the same chip with all the required interfaces).

For still sane but really budget-stressed project the $10 Cypress PSoC would be another sensible learning choice. It is ARM Cortex M3 with 24 CPLD-like Universal Digital Blocks. And the whole development toolchain for it is free from Cypress Semiconductor without the need to be affiliated with an educational institution.

In my opinion soldering 74-series chips by hand is a skill about as useful as knowledge of the railroad engineer on how to operate a steam locomotive. We have 21st century now. Search for "Xilinx ISE schematic capture" and get on with the program...

Edit: grammar fixes
10  Bitcoin / Hardware / Re: Bitcoin Core calculator, can it be home brewed? on: September 17, 2015, 02:27:15 PM
im glad you know how these work, you could basically lay it out what logic is required to do what calculation..

 "bit twiddling that in hardware can be implemented mostly with wires and very few gates."
so 2 or 3 gates and wires will calculate square root, drop the whole numbers, shift up and then convert the decimal to hex, of first 8 prime numbers?
if you say yes, show me a boolean logic layout.

Really, if you going to come here to belittle us, bugger off. Simple.

I want to know how these things work, I'm a visual learner, and hell, if it is possible to make them, why the hell not? common, GBG made a NES mine bitcoins.. why cant I make a handful of transistors do it? or even out of 7400 series ttl chips..
I don't know what your psychological disability is, so I can't help you.

The information required to solve all the technical problems to implement hardware SHA-256 miner is all available here on this board. Multiple people did their own implementation using the sensible learning technology of the XXI century: FPGA development kit. It takes between a week or a month to do it from scratch, depending on the student's aptitude. Simple FPGA development kits cost less than $100, many schools can get them for free.

For the problem you posed I think you misunderstood the description of Ki constants in the FIPS-180. FIPS describes how to derive them to show that those are "nothing-up-my-sleeve" numbers. Any hardware implementation will simply store those constants in ROM or other storage device.

11  Bitcoin / Hardware / Re: Bitcoin Core calculator, can it be home brewed? on: September 17, 2015, 06:09:56 AM
The whole point is that rolled (not-unrolled) SHA-256 will require less gates than the serializer plus deserializer and the sequencers required to interface with anything less than 32-bit wide.

SHA-256 is essentially a 16-position shift register that is 32-bit wide. The fancy hashing feedback is mostly 32-bit wide adders and some bit twiddling that in hardware can be implemented mostly with wires and very few gates.

The above 32-bit circuit will be trivial to interface to the computer provided that  the computer has a 32-bit bus like EISA or PCI-X.

With any narrower bus more gates will go into the required sequencing logic than into the actual hash computation.

Show me any USB chip that can put-out or latch-in 32 bits in parallel.

All this doesn't require decades of engineering experience. Even completely cursory understanding of the evolution of the PC-compatible computers is sufficient to understand that the wide ribbon cables and long edge connectors disappeared from the computers only very recently. In the TTL days of SSI/MSI chips all interfaces were parallel and as wide as people could afford.
12  Bitcoin / Hardware / Re: Bitcoin Core calculator, can it be home brewed? on: September 17, 2015, 04:56:58 AM
You all guys deserve an F for your TTL logic design proposals involving serial interfaces.

Y'all need to hit the books and get a refresher on why all early computer interfaces were parallel: printers, disk drives, floppies, everything had wide cables: ribbons or Centronics or other SCSI connectors.

The serial interface revolution was made possible only by the cheap LSI ICs.

I don't remember Intel part numbers off hand, but go lookup the early Zilog parts from the Z80 family: PIO vs. SIO. And those were 8-bit parts. You will need at least 32-bit wide interfaces to sensibly implement in TTL the key component of SHA-256: 32-bit carry-look-ahead adder using 74181 and 74182, which are 4-bit slice parts.
13  Bitcoin / Hardware / Re: Bitcoin Core calculator, can it be home brewed? on: September 17, 2015, 02:42:38 AM
Even doing this out of 74xx logic would be pretty sexy. I'd run one.
And how would you interface it with a computer with a network interface? I mean without using more TTL chips for the interface than for the computation core?
14  Bitcoin / Development & Technical Discussion / Re: Synchronizing wallet balance from a pruned node on: September 02, 2015, 10:47:48 PM
Right now the wallet in Bitcoin Core is disabled if pruning is enable, so I don't think that will work
It is my understanding that removing this restriction is a high priority task item for the Bitcoin Core developers. I don't exactly follow their progress, but many people expressed interest in having both pruning and wallet working at the same time.

I should've quoted this portion of your original message in my reply.

3) A third way would be to open the UTXO BerkeleyDB database file (can this be done while Bitcoin Core is running?) and then check if our addresses match.

Yes, this can be done for BerkeleyDB but not for LevelDB. Apparently there exist code that is LevelDB-compatible and fully multiuser/multitasking but it is only available from Google for money and NDA.
15  Bitcoin / Development & Technical Discussion / Re: Synchronizing wallet balance from a pruned node on: September 02, 2015, 07:27:08 PM
Probably the easiest way is to run Bitcoin Core with -privdb=0 flag and reopen the wallet.dat in a shared mode. You'll still have to make RPC calls to populate addresses, but at least transactions can be queried live through BerkeleyDB API.
16  Bitcoin / Hardware / Re: Swedish ASIC miner company on: September 01, 2015, 12:48:55 AM
So, then the Temperature column on status page is strictly a ambient reading only =)
Well, I would really advise you to investigate markings on all chips on the board and see if any other contains something LM75-compatible. It should be fairly easy and safe to do the tests by touching the plastic cap of the chip with a soldering iron and look for any temperature readout to rise sharply.

The continuing popularity of an obsolete chip like LM75 was perplexing to me. Apparently it is still being used as in the last-resort over-temperature protection circuits. When not programmed in any way it will power-up as an over-temp protection set to trigger at 80 degrees Celsius.

On this miner it may be wired up to shut it down when the in-cube ambient temperature goes over 80C, which will serve as a sort of pre-fire-protection circuit even if the programmable controllers are hung or disconnected.

17  Bitcoin / Hardware / Re: Swedish ASIC miner company on: September 01, 2015, 12:24:45 AM
Well, my question regarding LM75 is , is it the sensor itself or is it just the IC for a remote sensor probe?
Well, the LM75 physical IC is for sure a local sensor only.

On the other hand, if you are looking at the code commented as "reading from LM75" there is a whole bunch of "LM75 register-compatible" ICs that could be using both local and remote sensors.
18  Bitcoin / Hardware / Re: Request for Discussion: proposal for standard modular rack miner on: August 22, 2015, 07:15:04 AM
We checked several other miners for heatsink size comparisons.
I guess I'm overly cautious. I always worked on the devices with very strict quality assurance requirements: medical or industrial. Things like self-adhesive thermal pads were unacceptable, only mica leaves would do.

The lottery-ticket-printing devices that you are designing have much shorter lifespan, so a more relaxed design approach may be used. On the other hand, things like retail GPU cards have very carefully designed heathsinks: the die or at most 2 dies are in the center, everything else has a heat spreader or some other kind of interposer.

2112 - have you talked to PlanetCrypto about chip dev at all? I figured something like what he's doing might interest you.
It is interesting, but I need to keep my nose very close to my own grindstone. I'm not in the position to really get involved in the new projects. I'm fine with openly sharing knowledge and commenting in public on the forum.
19  Bitcoin / Hardware / Re: Request for Discussion: proposal for standard modular rack miner on: August 22, 2015, 12:03:20 AM
I guess after re-reading the original post I missed the fact that the hashing chips may be in the supply-voltage-serial a.k.a. string configuration. Since each chip will have different ground potential then there is some sort of galvanic isolation provided between the chips and the heathsinks.

So the heathsinks may be able to slide over their isolation layer enough to accommodate thermal expansion.
20  Bitcoin / Hardware / Re: BITMAIN launches 4th generation Bitcoin mining ASIC: BM1385 on: August 21, 2015, 11:15:43 PM
You have completely the wrong view of full custom, a rolled design would be a really dumb idea for a modern mining chip and very area inefficient, the customisation involves only two circuit elements, but I'm sure you know that. Not rocket science at all, no magic, and very little risk if you have some respect for semiconductor physics. DRC is there for very good reasons which again I'm sure you know, and only an idiot would even consider violating them.
The rolled vs. unrolled isn't a fully resolved choice. The losses and noise in the very long lines that drag the signals over 15 SHA-256 rounds are quite significant. I think the bitfury approach of routing hashed words in one direction and constant SHA coefficients in a perpendicular direction gives overall savings over trying to squeeze combinatorial optimizations after fully unrolling. Most of the combinatorial optimization gain is achieved by SHA-256 round pairing, i.e. 32 round-pairs instead of by-the-FIPS explicit 64 single-rounds.

I did not do a full analog modeling of both choices (rolled/unrolled) for SHA-256. But I've done something similar in the past that was bound by the speed of carry-look-ahead adders. I actually doubt that anyone here on this forum (maybe with exception of bitfury) did the required tradeoff analysis. My scientific will-ass guess is that Bitcoin miner has a possibility of being an example of one such circuits where leaving things rolled will be of great benefit. The very high toggle ratio (only -6dB below the theoretical maximum of a ring oscillator) will probably benefit from using some sort of SCL (source-coupled logic) or CML (current-mode logic) instead of the garden-variety CMOS bang-bangs that every CAD monkey throws at the Bitcoin mining problem.

People do fully unrolled hashers because the logic synthesis tools use heuristic place & route algorithms that don't converge or converge extremely slowly on the rolled designs.

As far as I understand the full DRC compliance at 28nm "mature" process is very, very conservative. I don't have any exact numbers handy, but the assumed gate  error ratios for a "digital" manufacturing process are way too high for Bitcoin miner that can easily tolerate a percentage point of errors. Violating some of the DRC to shed the unnecessary margins is one of the simplest ways to save power, after the obvious things like dropping JTAG and other testability overheads.

Re-reading your first sentence, I don't really understand the part
the customisation involves only two circuit elements, but I'm sure you know that.
Could you restate what you had in mind?
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