If you pull the blue wire from the fan connector your fan should stay at full speed full-time. If you're going to operate remotely anyway and nobody's home to hear it be super loud forever, that's a good way to make sure it also stays maximally cool.

I like that they're selling S5 preorders but they're only charging the deposit price, not the actual price after the second half is paid which must be paid before shipping.

And mining bitcoins instead of whatever else pump-and-dump is much less likely to be profiting by ripping off n00bs. You know, if you have a conscience.

http://gekkoscience.com/philosophy.html


Certainly not ours.

Well. Screw those guys anyways.

It's what we've always done, and probably always will do. Likely we'll send prototype boards to a couple trusted members for "beta testing" as well, before taking in money.

12 feedbacks as a seller within the past month, all private listings. I wonder how many of those sales also had BTC buyers get hosed off the books?

Right now what I really need is nine-day weeks. I literally have four different jobs to work on for four different people in the next six days, which will probably require about 50 hours in the shop and 20 hours on the road. On top of the two different in-house design projects I'm working on, as well as maintaining the hosting facility. I spent this evening laying out a gEDA footprint for the 37-pad BM1384, and hopefully tomorrow after batching out about 70 D750 boards I'll have time to start working up a breakout board PCB design for it. We'll have to get a few run out from a quick-turn fab house so Novak can start the particulars on chip comms while I work on regulation and maybe bust out a stickminer PCB as a refinement from the breakout board design.

If I do a stickminer we might just open-source it. I can gauge interest for a manufacturing batch if I can get good chip prices from Bitmain. Likely it'd use the same cgminer as the U1/U2. Voltage would be fixed probably at 0.65V or so, meaning a practical max of 10GH at around 3.1W hopefully for no more than about $20 each.
Heatsinking will be fun to figure out since the chip is a top-cooler.

I think we're good on computer parts and such for now, Phil. What we really need is more time. Or maybe a tech-literate sidekick to help out around the shop but doesn't expect to get paid.

10 of our chips were free samples, but I wanted more to play with so we could get at least one full prototype out of it with extras to blow up accidentally.

To be more specific regarding investors or project donations or anything like that, we're deliberately not taking in outside money until the entire design is complete. For one, people tossing in outside money usually want to think their money buys them decision-making privileges and that's not how we operate. For two, if something goes wrong and we don't finish the project or by the time we finish the chips aren't available anymore or it'd cost too much to batch the boards, nobody except us gets screwed and we don't have to pay anyone back. For three, nobody should be asked to front someone else's dev costs. Isn't that the primary reason preorders suck? Because someone asks you to pay for a thing which doesn't exist and which they can't guarantee actually will? We deliberately do not do this. We've taken preorders before (our first batch of DPS2K boards were a preorder) but only after the design had been completed, and prototyped, and thoroughly tested on our own dime. That's the way it is and the way it's gonna be.
If we get in a real bind and we're really close to finished but unable to scrape up resources for a test PCB run or something, maybe MAYBE we'll ask for an advance. Or take it from the sandwich fund. But no big money until we're ready to manufacture.

What are your older machines?

That depends on how you define "investor". We won't take anything except sandwiches until basically all the design work is finished and we're ready to line up production. At that point, we'll probably have to bring in outside money to run out an initial batch but the assumption is folks putting in money will want boards in return.

I asked Dogie, and he got me an email address and I asked them for samples and they gave me a price. I bought 40, and we'll probably end up using all of them.

Novak's poking around on the S1 controller now to see what its interfacing is like. Thing is, with our modular board size there'd be 4 UARTs required per S1 and it appears the S1's controller on has (or breaks out) two. It'd be nigh impossible to do a chain-up/chain-down for two boards because the chips are hardware-addressed. Unless we set a high bit on a common line that the user could jumper as 0 or 1 so the controller could tell the two boards apart? But that kinda makes routing suck.

If we intended on doing an S1 Upgrade Kit only, we could probably make it directly compatible. But that's not what we're going for.

Also, thanks for the sammich money. Tuesdays are usually sandwich days around here.

Actually, since the BM1384 takes most of its heat out the top, we'll really only have to worry about it being the highest point on the board on one side of the board. That's also going to be a limitation for a USB miner.

Rows are logical. We're nowhere near layout stage yet but there hasn't been any talk of not putting the chips in rows.

I was even thinking about putting edge connector pads on the board in case someone wanted to backplane them, which could get interesting. Basically a backplane with power and a USB pair to each socket, have a hub chip on the backplane and there you have it.

We may try and come up with a closed-form solution for a one- or two-board Jalapeno miner but in general the boards would be available barebones.

I don't know enough about the S1 or S3 controllers to say if that'll be straighforward or not. We want something flexible, so the most flexible option is simply a USB with a cgminer driver. It's not specifically an S1/S3 upgrade, it's a modular mining board that will be sized to mount on an S1 chassis but can also be run in infinite other configurations. With that in mind, making it work for an S1/S3 controller will not be a priority. Not when you can get unpowered hubs for few dollars and oughtta be able to run a bucket of 'em off a single host.

No idea on when they'd be available. Right now we're working on being able to communicate with a single chip. Once that's done it shouldn't be too far to get a passel of 'em going, but making sure the whole thing is rock-solid reliable will mean we don't just throw it together. Plus prototypes for any PCBs will be at least a week getting made. And then if we haven't fetched a pick-and-place yet...

Funding for an initial batch will depend heavily on chip costs. We're guessing probably around $30k for 500 boards but hopefully that's a high estimate.


Sandwich donations can be forwarded to 1BURGERAXHH6Yi6LRybRJK7ybEm5m5HwTr
We tend to lean pretty heavily on the Bacon Texas Cheesesteak Melt from Waffle House. Just throwing that out there.

So Novak and I have been rolling around an idea for a miner since about December. We were inspired by ASICMiner's BE300 sample chip test results and thought we had a pretty solid idea for a machine built around them.

Unfortunately, AM's BE300 doesn't really exist outside of those test chips, and it's quite probable it never will.

Bitmain's BM1384 (the chip inside the S5), however, is a fair substitute. Its bottom-end power efficiency compares to the BE300's midrange, the core voltages are a bit more manageable and the chained comms setup appears to be easier to work with. We ended up buying some sample BM1384 from Bitmain and the chips arrived on Monday, so now we can start playing with them. The datasheet is incredibly sparse regarding any kind of protocols, but fortunately the signalling appears to be identical from the BM1380 (S1/S2/U1/U2) and BM1382 (S3,S4,U3) so it shouldn't be too hard to figure out.

I did a bit of prodding on an S5 yesterday and got the comms topology and level-shifting pretty well figured out. Some prodding on a U2 has given us info on USB interfacing to the chip chain. Novak's tearing into U3 cgminer drivers to iron out data specifics and I'm going to work on the regulators and digital IO requirements.

The next step, which I'll be working on this afternoon, is to design a simple BM1384 breakout board that consolidates power lines and puts signals on a simple header. With a two-chip board on independent planes we can test one-chip comms, parallel node comms and string comms to get a basic understanding of topology changes.

It occurred to us that a simplification of this breakout board could be an effective USB stick miner which might be capable of 10GH around 3W of draw. We may design a PCB for this if there's enough interest.

The primary goal is to build a simple board which would be USB-connected to a controller, and capable of adjusting both core voltages and clock speeds using cgminer flags. We're looking at a single board capable of 300GH at 150W, downclockable to around 150GH 50W. At mid- or low-range settings it could be run off a brick with a quiet 120mm fan and heatsink and be a decen Jalapeno-formfactor home desk miner. The board will be designed specifically so that four of them would mount to an S1 chassis. Couple that with a 4-port USB hub and a Pi or something as the controller, and you have an "S1 Upgrade Kit" which will aim for 1.3TH at 600W clockable down to 600GH about 160W. These are board-level power estimates. This board is codenamed "TypeZero". We're trying to iron out a design that would incorporate the overall efficiency (both in power and cost) of string topology and the flexibility of standard VRM topology. Basically we're trying to take the best parts of several decent designs and make one thing that should be modular, flexible, reliable, affordable and efficient. Lofty goals to be sure, but hey why not aim for the top?

A secondary goal would be to design another board which could mount to a Prisma chassis. Modifying our design to a similar power density as a Prisma (1KW board-level) we could see a 2.4GH miner downclockable to about 1.1TH at 300W. There are other prerequisites to meet before considering moving forward on this, however.

We're a pretty low-fund operation these days, but we have some big jobs coming in which might be able to provide capital for a batch. In the worst case, we might try and open a preorder (grumble grumble) once we have a tested working prototype and solid final design. Manufacturing feasibility is going to depend heavily on the chip cost from Bitmain. With the "upgrade kit" savings of not having to manufacture heatsink chassis and controllers (and then pay to ship it all everywhere), the bulk of BOM expense is going to be ASIC costs, most likely. We've always liked doing things for home miners, and trying to keep prices fair, so we'll do our best to get these things made in a way that doesn't suck for everyone.

If it takes forever for anything to happen and Bitmain's already out of BM1384 and selling the BM1386 or whatever, it shouldn't take much to modify the design for the new chip. Assuming they don't make major changes to the comm protocols, which they haven't done yet so that's encouraging.

So, questions? Comments? Sandwiches? We're not really getting paid to design all this stuff so "keep up the good work" sandwich donations are more than welcome (1BURGERAXHH6Yi6LRybRJK7ybEm5m5HwTr).

I was really hoping the BE300 chips would be manufactured and available to third parties. My guess is the Prisma debacle hurt their bottom line quite a bit, what with offering replacement machines and full refunds on them even a couple months after. They probably lost a lot of coin on that deal.

I wonder what they're going to decide to do with the BE300 IP if the company goes under. They probably have a lot of dev costs to recoup from that, and if it's ready to send to a foundry someone else could buy it and have some pretty sweet chips in hand. Their top-end efficiency is right at Bitmain's bottom-end efficiency, they're at worst comparable to Bitfurys reported stock and would make some really nice flexible gear pretty easily.

If that PSU has active PFC (which I certainly hope it does, over 1KW output rated) the input voltage should have zero effect on the output voltage with no external interaction required. The active PFC pulls current from the AC line approximating a resistive load and internally boosts it to a ~350V internal DC bus (pretty much regardless of input voltage) which gets switched down to the high-current 12V output.

I should have seen that price drop coming and warned everyone. Whenever we take in large orders or invoices paid in coin, the exchange rate always plummets immediately after. Every single time. It's a curse. So yesterday we took in something like 15BTC on one invoice, of course it drops overnight.

Maybe. I don't have a board to compare to (I own zero Cointerra gear) but it might not be hard to fashion a replacement. Or at least take a look at it.