If you’ve ever wanted to get into the Bitcoin game for fun and profit, this new $400 gadget could be the best way to do so.21 Inc.’s Bitcoin Computer is a tiny Linux-based box that lets you mine the cryptocurrency and buy and sell digital goods for Bitcoin, either independently or plugged into a PC.It includes a micropayments server that lets you receive payments for your offerings, meaning you don’t rely on a third-party service that will take a cut of your earnings.Of course, you shouldn’t expect to get rich just by leaving the device plugged in to mine Bitcoin.The company believes its new product makes it easy for users to earn revenue by selling internet-accessible goods and services like machine translation, apps and media, renting out a 3D printer or microtasks like tweeting.21 is backed by the likes of Andreessen Horowitz, Qualcomm, Cisco, and PayPal co-founder Peter Thiel, and has a long-term vision for Bitcoin that goes beyond its speculation value.Describing how machine-to-machine payments could solve numberous problems for Web users, Andreessen Horowitz co-founder Ben Horowitz told The Wall Street Journal: If I could read stuff on the web for a small amount of money, and didn’t have to open myself up for repeated charging or subscriptions I didn’t want?

That’s a relatively straightforward application if you have machine-to-machine payments.21’s device includes an energy-efficient mining chip, a custom version of Linux with the Bitcoin protocol baked in, as well as a 128GB SD card that contains the entire Bitcoin blockchain so you can run the computer as a full node to mine currency.The $400 computer will ship on November 16 and is available to pre-order now from Amazon.Interestingly, you can’t buy it with Bitcoin yet — but the company says it will enable the option to do so in the near future.bitcoin kaufen elv➤ 21 [via Balaji S Srinivasan on Medium] Read next: Apple subtly rickrolled everyone and it's hilariousbitcoin fallacyThis is the second in a two-part series exploring Butterfly Labs and its lineup of dedicated Bitcoin-mining hardware.bitcoin synchronisation dauert ewig

In part one, we looked at the company and the experiences customers have had with it.In part two, we share our experiences running a Bitcoin miner for a couple weeks.There is a whirring, whining presence in my dining room.I notice it every time I walk through.Every day, it sucks down about one full kilowatt-hour of electricity.In a year, it will consume almost $100 worth of juice—and that's on top of the $274 it costs to buy the box in the first place.bitcoin gadget windows 8Oh, and it's hot, too.bitcoin gladstoneIf I moved it into my office and could stand the noise, I could keep a cup of coffee comfortably warm on top of the thing.phineas gage bitcoinWhy on earth would anyone want such a disagreeable little machine in their home?The short answer: every day, that machine magically generates something like $20 in bitcoins.

Ars Senior Business Editor Cyrus Farivar tapped me on the shoulder a few weeks back with a proposition."I've got a Butterfly Labs Bitcoin mining box," he explained."There aren't that many in the wild right now.I'm working on a story about the company, but I'm about to go on vacation.Do you want to see if you can get the thing working while I'm out?"That's the electronic currency that's quickly rocketed from lame nerd project to ludicrously valuable hot topic, right?I didn't know a lot about the world of Bitcoin other than the fact that "mining" them involved people building custom PCs with tons of video cards to handle the math.I certainly didn't know how to "mine" bitcoins myself or what to do with the things once I had them.I just knew that people eventually try to trade them in for cash somehow (but how to do that was also a total mystery).And yet here was the opportunity to take a piece of hardware I'd never heard of and see if I could use it to magically create some money out of nowhere.

I told Cyrus to send me the Butterfly Labs miner.As he trekked off to Peru for his vacation, I settled in with the little black box.Butterfly Labs is a company that has drawn a fair amount of controversy for what the Bitcoin community at large perceives as a string of broken promises.The company sells ASIC-based Bitcoin miners—machines that are built around customized chips that do nothing except compute SHA-256 hashes very quickly.Its smallest miner (the one I had to get working) is codenamed "Jalapeño" and computes a bit over five billion hashes per second (or 5GH/s).The problem is that Butterfly Labs started selling the machines long before it actually had a product to sell.It began taking paid-in-full preorders back in mid-2012, and thousands of customers opened their wallets for Bitcoin miners ranging from the small 5GH/s miner at $274 all the way up to the large 500Gh/s miner, which costs $22,484.Butterfly Labs promised certain performance targets to customers—it initially felt confident that its application-specific integrated circuit (ASIC) designs would deliver one billion hashes per second for every 1.1 watt of power consumed.

This proved extremely optimistic.Hardware delivery slipped multiple times.Now, a full year later, the first few real live Butterfly Labs boxes are finally being shipped, though no small number (as many as 30) were sent to journalists to review rather than to paying customers.But when the little black box showed up on my doorstep, I had no idea about the deep and extremely vocal Bitcoin community or the story behind Butterfly Labs.I didn't really even fully understand what the miner did.I simply knew that I wanted to get this thing working and make some money.The 5GH/s Jalapeño miner is a black rounded cube with a brushed metal finish.The only connectors on the exterior of the device are on the back: a mini-USB port for data and a power plug.Near the power plug are a series of small red LEDs that the device uses to tell you its status, though there was no documentation in the box to explain what the LEDs meant.The front of the cube contains another red LED to indicate power.There are two sets of vents, one low on the front and the other high on the rear.

The device's internal 80 mm fan draws cooler air up from the front through the fins of the large heat sink mounted on the ASIC chip.It expels the now-warm air out through the top vents.After I unboxed the thing and took some photos, I was sort of stuck.I had no idea what to do with the little rounded-off cube.Before I consulted the Internet for documentation, I tried briefly—and in vain—to see if I could make it work on my own."I am a geek, and I work at Ars Technica, which is a major technology website of some renown," I thought."I have built Web servers.I use, like, Linux and stuff.How hard can this really be?"Connecting it via USB to any of the computers I had handy didn't really cause anything to happen.The device showed up on the USB bus and identified itself, but it didn't do anything.I naively wondered if there was some kind of application I needed to download to "log on" to the device to get it mining.I admitted defeat and consulted the Internet.Unfortunately, as I was to quickly learn, I was coming at the miner with a certain set of false assumptions.