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Batteriser is a $2.50 gadget that extends alkaline battery life 800% macworld.com
141 points by chris-at  2 hours ago   66 comments top 19
jwr 2 hours ago 2 replies      
One should be careful evaluating the claims.

A good boost converter will be ~90% efficient (it can be more efficient, but not miniaturized like the pictures show). So, to begin with, you'll discard ~10% of your energy.

Now look at AA alkaline discharge curves: http://www.powerstream.com/AA-tests.htm

Indeed if you gadget reports the batteries as dead at 1.25V, you can still get ~40% more usage. But most gadgets don't work that way. 1.25V is the normal voltage of a fully charged NiMH rechargeable AA, so if you gadget works with those, the real cutoff point is likely closer to 1.15V or so.

The booster will boost the voltage (at the expense of current, obviously, plus losses) so that even though the battery will be below 1.15V, output voltage will be at 1.5V. Looking at the graphs, this buys you less than 1/5th, and if you consider the losses in the boost converter, probably half that.

The "800%" claim seems totally bogus. Perhaps with a gadget that stops working when the voltage falls below 1.45V per cell.

I'm not saying it's not a useful gadget (and I'm very impressed by the miniaturization: where is the inductor? This thing must run at several MHz at least!) just that the claims should be taken with a large grain of salt.

throwaway434317 1 hour ago 4 replies      
How can other posters take this article at face value? This reads 100% like a fake ad (I mean stylistically and in terms of presentation, like the kind of thing you see "Advertisement" written in small text over the top of while it's run in the New Yorker or wherever. I read them. I like it. Because they're amusing.) The only thing that keeps it from being one is that it's on macworld.com. Like, really? Industrial espionage, a real "professional job"? "Big Battery"? Everyone here has worked on way more interesting technology than a metal sleeve and a farfetched tale - which is all this is - and who breaks into our offices to steal our tech? It doesn't happen. Nobody would do it even if the device works exactly as stated.

Do these prototypes look to you like something that came out of a test lab? The only work put into them is the branding, "Batteriser" a word that is mentioned 43 times in 2000 words, including the first word of the title.

I'm not calling this native advertising but if it isn't, it seems the only one more gullible than this journalist is everyone else who swallows this hook, line, and sinker.

You could have written the same article but with some doohickey that lowers gas mileage by increasing oxygen mixture, and gets stolen in a brazen act of industrial espionage, a real professional job.

come on. we're adults here. this article is insulting. Where are the details of the break-in, such as date or what precisely was stolen, or where it happened - you know: journalism?

noonespecial 1 minute ago 0 replies      
Strange that he picked a mac keyboard for the demo. Mine works until the batteries reach 0.8v each. Batteries that are long "dead" in my kids toys make my keyboard work for weeks.

The trackpad on the other hand...

userbinator 2 hours ago 2 replies      
Batteroo says the sleeve and its boost circuitry doesn't introduce any extra risk of chemical leakage.

From http://en.wikipedia.org/wiki/Alkaline_battery#Leaks

The reason for leaks is that as batteries discharge either through usage or gradual self-discharge the chemistry of the cells changes and some hydrogen gas is generated. This out-gassing increases pressure in the battery. Eventually, the excess pressure either ruptures the insulating seals at the end of the battery, or the outer metal canister, or both.

In other words by extracting more energy, there is more hydrogen evolved and it will increase their tendency to leak.

This was also posted on an EE forum I frequent, and the opinions on it so far have been mostly negative:


IMHO rechargeable lithium is the way to go. An 18650 has several times the energy of an AA while being not much bigger, and can be recharged. They're still not all that common in the West, but equipment like torches, power banks, and portable fans which take 18650s are gaining in popularity.

drodgers 34 minutes ago 0 replies      
"Batteriser can continue to deliver a 1.5 volt charge in batteries that have discharged down to 0.6 volts. There are more than eight 0.1 volt steps between 0.6 and 1.5 volts, so, in grossly simplified terms, the Batteriser can extend operational battery life somewhere around a factor of eight."


No. That's not how maths works.

afandian 2 hours ago 3 replies      
If this is such a great idea why isn't the circuit integrated into the devices that use batteries? I'm sure it wouldn't be difficult monitor the discharge rate and kick in the circuit when it's needed and the battery has demonstrated that it's an alkaline by its discharge profile.
Confiks 19 minutes ago 0 replies      
I do think that the claims made by Macworld are somewhat exaggerated. This kind of journalism always needs to be taken with some grains of salt. The paragraph in which the 800% extension is described, sounds messy, and doesn't cohere with some other claims made in the article.

The motivation of the story, namely that of a robbery of private documents, seems odd, and I can understand that it will immediately raise red flags among readers.

Some other points in the article did seem plausible to me. Modern electronics need stable voltages to keep working properly. The working of voltage regulators is well understood. Only the miniaturization is the invention, which is patented (https://www.google.com/patents/US20120121943), and has a very verbose application compared to other patents. There can of course be issues with the technology, of which theories are offered by some commenters.

Another patent by "Frankie Roohparvar" (and not Bob as in the article), can be found here: https://www.google.com/patents/US6717853 , and Mr. Roohparvar can be seen talking (presumably; I only skipped around) here: https://www.youtube.com/watch?v=1V6IKoFhBtQ

For some theories that commenters are offering, an elaborate conspiracy would be required, building up references and trust, only to mislead absolutely and quite likely not get away with it.

Of course, conspiracies exist, but please don't think so lightly about arguing them.

ferongr 12 minutes ago 0 replies      
You won't get much power (Wh, as opposed to mAh) from a cell at a low state of charge. The initial lower voltage of the almost empty cell, combined with the increased voltage sag under load due to the converter pulling increased amounts of current will result in dubious amounts of actual extra energy. In any case, many complicated electronic gadgets already use some kind of voltage regulator that maximizes the runtime of the device, this gadget (if it works as advertised) would be useful only for some direct-drive lights or motors
skyshine 23 minutes ago 1 reply      
Could these be used to boost NiMH to 1.5 volts?

Could I finally stop throwing money at my smoke detector which always throws a fit at about 2AM if I try and put NiMH in it?

joosters 11 minutes ago 0 replies      
Where are the published 3rd party test results? If all they say is true, it would be simple & cheap to get an independent test done showing a range of devices and the run times with & without the batteriser.

Their one-line statement from Dr. Kiumars Parvin is worthless on its own. Show some confirmed test results on real life items, or you are just selling snake oil.

pjc50 2 hours ago 2 replies      
This is a very nifty commercialisation and miniturisation of the "joule thief" circuit, a type of switchmode power supply.
michaelt 2 hours ago 2 replies      

 The time it takes for the battery voltage to drop by 0.1V is longer at lower voltages versus at higher voltages. That means that if a constant current was drawn from the battery, it would take the battery a lot longer to discharge from 1.2V to 1.1V than it would from 1.5V to 1.4V. This means that the extent to which the battery life is increased could be even higher.
Sure, but if you're drawing 20mA at 1.5v, you only need to draw 20mA from a 1.5v battery. If the battery drops to 1.2 volts, for constant power output you'll need to pull 25mA into the boost converter.

cryodesign 1 hour ago 1 reply      
Why would I want to buy this gadget compared to investing my money in rechargeable batteries? I would probably use non-rechargeables for smoke detectors only.

Also the environmental impact is less with rechargeable batteries[1]

[1] http://ec.europa.eu/environment/waste/batteries/pdf/battery_...

Edit: fix typos

jacquesm 2 hours ago 2 replies      
That's clever. I used a similar trick to boost the output of my windmill during low-wind days when the voltage from the alternator would not be larger than the voltage of the batteries.

I don't understand this bit:

> The next step is an Indiegogo campaign in late June, and then delivery in late September.

If they already have a working product and a price set and they're going to ship in September they should be well into mass production right now and such a campaign would not make much sense.

If made cheap enough the circuitry could possibly be internalized in the battery sleeve.

chrisBob 38 minutes ago 0 replies      
One issue I don't see addressed is that I appreciate the warning I get as my batteries die. In an apple trackpad, like the one in the "article", I get a few weeks notice when my batteries are dying. With this am I more likely to have devices just give up suddenly?

That, plus the safety concerns and the fact that their math is bogus will probably keep me from using one.

mschuster91 1 hour ago 1 reply      
How is this supposed to work w/ rechargeable batteries? Deep-discharging can permanently kill a battery.
josefresco 1 hour ago 1 reply      
I got about 3 paragraphs in before my browser succumbed to the atrocious ad/JS bloat on this site. I'll hunt down a mirror/print version.
kabouseng 2 hours ago 3 replies      
I'm not sure if it is a good idea to use this device with your rechargeable batteries...
PythonicAlpha 1 hour ago 0 replies      
I just wonder, if the video is part of a new, clever (or not) marketing strategy?

At least at my computer (tried with two different browsers), the video stops after 17sec or so and is interrupted in midst of a sentence by a form to enter my email address. I just wanted to view the video to the end, but have to enter my email instead??

Either an error in the page (?) or a clever marketing strategy?? In my case, not so clever, because I will not adhere to such tactics.

It could also be, that the whole thing is similar to that tactics? As jwf also pointed out, the claims are a little over the top. I don't think, that 800% are really achievable. Maybe 20-30% in real life applications. That of course could be still good, when the gadget will not be to costly and is unlimited reusable. Still the question remains, if simple rechargeable are not still better (for your economy and the environment) in cases where you have battery-intensive applications. I try to limit the usage of non-rechargeables to cases where the battery is swapped really seldom -- and in such cases, additional gadgets just make life more complicated.

Install OS X 10.10 Yosemite in VirtualBox frd.mn
115 points by frdmn  3 hours ago   52 comments top 7
rmoriz 1 hour ago 0 replies      
There is a simpler solution out there using Hashicorps' Packer and the great build scripts from timsutton (can build images for Fusion and Parallels, too.):




wslh 1 hour ago 1 reply      
I used OS X in VMware and Virtualbox (running Xcode) and the experience was awful. Mainly because 3D support is not available and OS X makes a heavy use of graphics acceleration.

OS updates also break the installation.

There are many discussion threads on this topic, like this one https://communities.vmware.com/thread/466874

alkonaut 2 hours ago 2 replies      
It seems the image must be created on an existing OS X installation. Is a pre-baked image portable to virtualbox running on other host OS:es? (Yes I know, Eula yada yada).
arihant 37 minutes ago 0 replies      
Since Virtual Box supports EFI boot, and since we did not fiddle with the ISO in this process, that means this process will not work on incompatible older Macbooks, right?
kriro 2 hours ago 1 reply      
I'm thinking about getting a MBP (have one at work) because the hardware is shiny and OSX is useful/needed for some things (iOS development, Unity development).However I'd much rather run Linux as the base OS. That setup wouldn't violate the EULA. I guess I'll spin up a VB-image on this OSX-MBP and see how it goes :)Useful.
csvan 3 hours ago 4 replies      
Needless to say, this is a gross EULA violation (clarification: if you do it on non-Apple hardware, that is).
neals 3 hours ago 2 replies      
Would this run faster on a Windows-SDD than on a Mac-mini sloooow HDD?
Hola VPN Already Exploited by Bad Guys, Security Firm Says torrentfreak.com
33 points by fraqed  2 hours ago   5 comments top 5
BoppreH 11 minutes ago 0 replies      
Selling user's bandwidth is shady, but consistent with VPN usage (i.e. traffic routing). You can present it as "hey, that's our actual business model, we just forgot to tell you guys" and maybe get away with it.

But this:

 Hola [...] installs its own code-signing certificate on the users system. Hola contains a built-in console (zconsole) that is not only constantly active but also has powerful functions including the ability to kill running processes, download a file and run it whilst bypassing anti-virus software plus read and write content to any IP address or device.
This is going so far into shady territory it becomes indistinguishable from actual malware. This is Lenovo/Superfish all over again.

ThePhysicist 9 minutes ago 0 replies      
Hola is going down a dangerous route here by turning all of their users into exit nodes, but if they actually make this work it would give them a unique position among all VPN providers.

Legally this is a very risky endeavor though. In Germany for example (where I'm based), people are even scared of sharing their Internet contract with their neighbors since the account owner can be held responsible for any illegal activities (e.g. downloading copyrighted content) that are carried out through his/her connection. Allowing other people to "freeload" on my connection would therefore be a big no-no here. The only way around this risk would be to record and attribute the connection information to each user of the service, but this would of course eliminate many of the advantages of using a VPN again (e.g. privacy).

expertentipp 7 minutes ago 0 replies      
I wish to just use OpenVPN but it's not so easy. Certificates - no problem. Forward DNS requests - there is an option for it in the config file. Routing entire traffic through OpenVPN - quite tricky unless you're fluent in command line network management tools and computer networks in general.
jmkni 30 minutes ago 0 replies      
Hola really don't make it clear what you are installing when you download it.

All you think is, "I'm installing a browser add-on to watch Netflix in another country". You sort of assume it's only actually running when you are actively using it for Netflix, but it's running all of the time.

I first noticed something was up when I installed Hola (for Netflix) then all of a sudden Fiddler wouldn't work anymore. Had me completely stumped, then somebody on StackOverflow suggested turning off Hola and that indeed sorted it. - http://stackoverflow.com/a/19905099/969613

jalopy 32 minutes ago 0 replies      
Anyone have insights into the latest and greatest tools to search for and remove possible malware installed by Hola?
Thunderbolt 3 embraces USB Type-C connector, doubles bandwidth to 40Gbps arstechnica.co.uk
54 points by rbii  2 hours ago   16 comments top 4
berberous 1 hour ago 1 reply      
Can someone explain whether I should care that they are still using DP 1.2 rather than 1.3? I had thought 1.3 was needed for non stitched 4k 60hz, but this should have plenty of bandwidth, so I'm now not sure what the issue with 1.2 vs 1.3 is.
snarfy 18 minutes ago 1 reply      
The USB C connector is awesome and this is great news.

I still wish the industry would have standardized on the 2.5mm jack. It can be plugged in any direction. You could pull a cord out of a mess of cables and it would not snag as there is nothing to snag on.

Already__Taken 56 minutes ago 2 replies      
Seems to be trading all our different ports with the problem of having all levels of different cables?

This port is going to be very expensive for the manufactures. If it does everything I'm going to need a bunch. Does anything stop OEMs making a row of identical ports that only 1 charges my laptop, only a couple take can use the fastest cable and I'm sure all sorts of potential shenanigans,

awalton 46 minutes ago 5 replies      
Ugh Intel. We just fixed the USB problem of "I can't figure out which way to plug this thing in", why do you have to go and add the complication of "Wait, is this a Thunderbolt or USB C device/port?"

This is why we can't have nice things.

Thunderbolt 3 uses USB-C plug thunderbolttechnology.net
47 points by narfz  2 hours ago   27 comments top 6
izacus 51 minutes ago 3 replies      
Hmm, I don't understand the description fully - does that mean that it can happen that I can get a device with USB-C plug, plug it into computer and it won't work because the device uses Thunderbolt 3 and the computer isn't an Apple?

Or will all Thunderbolt 3 devices be able to scale back and communicate with devices over USB if the controller is not available? How will that work with displays over USB-C connectors? Is there a possibility that now instead of just checking for a USB port, we'll have to read the list of controllers/protocols available in devices connecting over USB-C ports?

jacobolus 1 hour ago 0 replies      
The linked site seems to be completely toast, but here are some secondary sources which Id guess have approximately the same content: http://www.cnet.com/news/thunderbolt-3-and-usb-type-c-join-f...http://www.pcworld.com/article/2929798/thunderbolt-3-to-work...http://www.theverge.com/2015/6/2/8704067/thunderbolt-3-usb-c...
hjnilsson 1 hour ago 5 replies      
And finally, the future has arrived. If the iPhone 7 (doubt the 6S) sports USB-C as well, there will be a truly universal connector. Imagine screens, laptops, TVs, phones, mp3 players, docks, hard drives and toasters all using the same plug (well, maybe not the last one). There will be a painful time of transition until we are there, but hopefully it will be the last one.

(Conveniently this also saves Apple on the new MPBs, they can now have both USB A and USB C ports without it being weird)

donatj 47 minutes ago 1 reply      
When Thunderbolt was first released it caused a lot of confusion in my office for people with DisplayPort who couldn't hook up to Thunderbolt monitors, bought for them by our IT group that really didn't understand the difference. I see this problem coming on strong AGAIN with this. This port is just USB-C while this other port is USB-C and Thunderbolt... That sounds like a load of confusion waiting to happen.
stephen_g 27 minutes ago 1 reply      
I'm interested in how backwards compatibility works - will old Thunderbolt devices work with just an adaptor cable? As someone who does a lot of professional video/audio work, I have a bunch of Thunderbolt devices so I hope that's the case.
out_of_protocol 50 minutes ago 1 reply      
One port to rule em all
How China's one-child policy has backfired on men newsweek.com
25 points by dctoedt  1 hour ago   12 comments top 5
meesterdude 16 minutes ago 1 reply      
Really great read; sheds light on some things I never understood about china, but now it makes sense.

Goverment: "Stop making so many babies! that's it, just one per couple."

Citizens: "well, if we can only have one, we better make sure it's a boy!"

What could go wrong?

Yes, woman are gaining some upper hand here; and thats good. But it's not because of a change of outlooks or perspectives of the people, it's simply out of scarcity of the gender.

And what happens when there aren't enough women to go around? why, they import them of course! And by import I mean sex slavery and arranged marriages.

"life...finds a way..." to keep on fuckin'

j_m_b 23 minutes ago 1 reply      
Ahh.. the unintended consequences of central planning.
jkyle 20 minutes ago 0 replies      
Overall, this would appear to be a good thing.
lectrick 21 minutes ago 0 replies      
For anyone who made a lot of money on Bitcoin during the runup (which was largely powered by Chinese buying and the Chinese "saving" mentality mentioned in this article)... you have the Chinese one-child policy to thank for your Teslas
transfire 24 minutes ago 2 replies      
They can look at as many corollary data plots as they like, but the simple explanation is that modern society has made men dispensable. A traditional "patriarchal" marriage is based on the woman's need of a man to provide for her and keep her safe, while the man's attachment to a woman is primarily one of desire. Now that modern society has made it possible for a woman to live well without a man, she is free to base her romantic relations on desire as well. Obviously these things take decades to play out, so we still see the primary desires of woman lean toward the financial capabilities of the male. But this will slowly change. For better or worse, family structures of the future will look nothing like those of the past. Single mothers will top 50% in China, just as it has in the USA, within two generations.
Guide to x86 assembly virginia.edu
18 points by georgerobinson  1 hour ago   5 comments top
melling 47 minutes ago 2 replies      
With ARM used for mobile, would it make more sense to learn it because these less powerful processors might provide more opportunity to use assembler?
Original Pentium FDIV flaw e-mail (1994) trnicely.net
44 points by shubhamjain  3 hours ago   8 comments top 4
wscott 1 hour ago 2 replies      
Ah yes, Dr Nicely caused quite a bit of excitement at Intel. I was on the p6 architecture team at the time.(p6 == Pentium Pro)Our FPU was formally verified and didn't have the same bug.

To be nice to Dr Nicely we sent him a pre-release p6 development system to test with his program to demonstrate that his bug was fixed. He was working on a prime number sieve program at the same and came back reporting that the p6 ran at 1/2 the speed of a Pentium for his code. Wow, another blackeye/firestorm caused by Dr. Nicely. He had too much of an audience for him to report to the world this new processor was slower.

So I got to spend a lot of time learning how to sieve works and what is happening. For the most part it allocates a huge array in memory with each byte representing a number. You walk the array with a stride of known primes setting bytes and whatever is left must be prime. ie. every 3 is not prime, every 5 is not prime, every 7 ....

So in the steady state you are writing a single byte to a cache line without reading anything. And every write hits a different cache line.

Now p6 had a write allocate cache, but the Pentium would only allocate on read, so on the Pentium a write that misses the cache would become a write to memory. On the p6 that write would need to load the cache line from memory into the cache and then the line in the cache was modified. And since every line in the cache was also modified we had to flush some other cache line first to make room. So every 1 byte write would become a 32-byte write to memory followed by a 32-byte read from memory.

Normally write allocate is a good thing, but in this case it was a killer. We were stumped.

Then the magic observation: 99% of these writes were marking a space that was already marked.When you get up to walking by large strides most of those were already covered by one of the smaller factors.

So if you changed the code from:

 array[N] = 1

 if (!array[N]) array[N] = 1
Now suddenly we are doing a read first, and after that read we skip the write so the data in the cache doesn't become modified and can be discarded in the future.

Also the p6 was a super-scalar machine that ran multiple iterations of this loop in parallel and could have multiple reads going to memory at the same time. With that small tweak the program got 4X faster and we went from being 1/2X the speed of a Pentium to being twice the speed. And this was at the same clock frequency! The test hardware ran 100Mhz, we released at 200Mhz and went up from there.

julianpye 1 hour ago 0 replies      
In the end despite the expensive recall, this was a big win for the Intel brand. The early processor years were tumultuous as on the battleground the 486 clones of Cyrix and TI lost. Intel went the Trademark way with the Pentium and the media embraced the incident as something that would sink them.

Although very few people would ever come across the bug, Intel allowed every processor to be exchanged. No matter if you were a gaming consumer or a giant corporation using coprocessor-heavy software.

So I remember a UPS driver coming by my student flat with an exchange processor and picking my faulty unit up a week later or so. It was incredible service that made Intel as a brand very reliable.

userbinator 2 hours ago 1 reply      
A more detailed explanation of the cause:


5 entries out of the 1066-entry lookup table were wrong. They probably didn't use test vectors that exercised all the entries.

But in general, testing complex ICs is hard. There are analogue effects too - if an instruction happens to make the right set of transistors switch in a certain way, going past the estimated margins, power supply fluctuations and crosstalk could flip a bit or two. Sometimes these bit-flips don't cause any problems since it happens in an unused part of the logic, but sometimes they do. As the enthusiasts who like to overclock have shown, it's easy to get something that looks like it works most of the time, but then completely crashes when executing just the right instructions.

caf 2 hours ago 0 replies      
PKZIP 2.04g, now there's a version number that fires a long-dormant set of neurons.
Show HN: InterviewBit Interactive Coach for Tech Interviews interviewbit.com
53 points by syshackbot  4 hours ago   35 comments top 11
nodesocket 3 hours ago 5 replies      
Nice job, but I really loathe tech interviews.

I've absolutely bombed tech interviews in the past, I now will refuse to do any. Particularly, because I've got some "street cred" with my startup, and basically my work with my company and GitHub speaks for my talents. I get it, you have to "vet" a candidate, but tech interviews in my opinion are not a good solution.

O(N) notation, data structures, academic computer science.... Rubbish.

eranation 1 hour ago 0 replies      
Well done, I'm really impressed, works well on mobile, feels like elevate for CS. Still lot of work, but better than anything else out there that I know of.

One obvious question: How do you plan to monetize? Become a hiring broker like piazza? Do these things work?

smcl 45 minutes ago 0 replies      
Thanks for this. I'm absolutely awful in Tech Interviews (I'm a competent developer but I'm overcome with self-doubt and anxiety in these situations) and I'm planning on a move very soon. I've been putting it off because of the stress of the interview process, so hopefully this will help!
andrei512 3 hours ago 1 reply      
zerr 3 hours ago 1 reply      
It is frustrating how much time and energy is wasted on these useless tech interviews when it really has nothing to do with most real world jobs out there.
mkagenius 1 hour ago 0 replies      
Hey OP, I found the parallax image kind of jerky on scroll. OSX, Chrome Latest.
hellboy_86 2 hours ago 0 replies      
very good sight for the preparation of interview.The coachs are very helpful,they will listen your problem even at midnight and tell you the way to solve the problem
dotdi 3 hours ago 0 replies      
The signup form seems to reject passwords with special characters but there are no indications besides "8 characters minimum". Kinda lame.
bunshin 2 hours ago 0 replies      
login/signup over http -
kriro 3 hours ago 0 replies      
I hope this doesn't sound unfriendly but that is a pretty "boring" PR post. People are generally way more interested in learning about your motivations and what you do and what drives you. So in the future I'd suggest a way more personal OP.

Also the recaptcha box is misaligned in the layout (FF curren, OSX/MBP).

simi_ 3 hours ago 3 replies      
Template modified from here [0]; doesn't inspire too much confidence to be honest.

0: http://startbootstrap.com/template-overviews/landing-page/

Show HN: A puzzle game inspired by functional programming, written in PureScript david-peter.de
54 points by sharkdp  6 hours ago   29 comments top 9
cies 2 hours ago 1 reply      
PureScript is a game changer. Compilation is fairly simple (unlike GHCJS), full Haskell'ish type system and modern/compact syntax, picked up a lot of momentum lately.

It find it by far the best AltJS implementation currently available.

Have a look at the code implementing the transformer functions, so clean!


Nice demo!

gholap 2 hours ago 1 reply      
Awesome game!The stackequal function is confusing though... Any help or description would've saved a lot of time...
fvirexi 1 hour ago 1 reply      
Amazing game!

On the "Fort" level, the map [blue][white]->[blue] removes the [blue] block, rather than the [white]. This is a different behavior than the map [red][red]->[blue], which converts two [red] into one [blue].

sharkdp 6 hours ago 4 replies      
This is still work in progress. I would love to hear your feedback.

GitHub link: https://github.com/sharkdp/cube-composer

glaberficken 1 hour ago 0 replies      
I know this is not reddit, but I couldn't resist being a bit juvenile about this =)http://imgur.com/9W6DGFj
thomasahle 1 hour ago 1 reply      
I solved the second one using stackEqual. Still have no idea what it does...

The interface is really fun though, and the blocks look nice. Only the "Solved!" text is quite small and not easy to spot.

ilya-pi 1 hour ago 1 reply      
This is so amazing, I love it so much! Very challenging, yet highly entertaining.
MegaLeon 2 hours ago 1 reply      
Thi is damn fun, well done. Any plans for a mobile version?
deepnet 2 hours ago 0 replies      
This is very challenging.

Very very challenging

Show HN: Diff.io diff.io
165 points by wickedlogic  10 hours ago   76 comments top 25
llamataboot 9 hours ago 2 replies      
I see some green blobs, some pricing info, and hear some marketing speak about letting my CMS be a "self-actuated change awareness system".

I want to know how I integrate this API into my tests, what exactly it tells me, and how to use it. How about a free plan to test it out? How about developer docs? How about something more than a few screenshots and a 30 second video that is incomprehensible marketroid speak?

Sorry for the harshness, but I really think visual diff tools are needed for integration testing. I want to figure out which ones are flexible and how they can be used. This site helps me do none of that.

schappim 6 hours ago 1 reply      
If you want a DIY version of this, try ImageMagick's compare command:

compare bag_frame1.gif bag_frame2.gif compare.gif

Documentation: http://www.imagemagick.org/Usage/compare/

nbevans 8 hours ago 6 replies      
Tip: Remove the "plans" page. This thing is too early stage to start talking about $ plans. Nobody even knows what the hell this is or what it is good for.

Your business model should be as follows:

1. Make something new, useful and free.2. Get people hooked on it, like a drug.3. Grow a modest user base.4. Introduce "value added" features, marked as preview or beta, for enterprise customers and integration into other web services.5. Once features added in step 4 have matured, remove the beta clauses and slap a price tag on them.

empressplay 8 hours ago 3 replies      
Your "bootstrap" level should be free. I don't see any bootstrapping startup paying for a service they don't need / can build themselves for free (if they're really desperate for it.)

You want to capture that potential future business, and hope that you can convert them to paying customers as they become profitable; you don't want them to go "hey, great idea, but I'm not paying for that" and then implement their own solution.

ivanhoe 46 minutes ago 0 replies      
Looks like a useful service. Just a word of warning, your SSL certificate is not trusted by Chrome and possibly some other browsers. You have to install Intermediate certificates to make it work for everyone.
morgante 9 hours ago 4 replies      
This seems like it could be greatcan I drop this into my CI workflow to find visual regressions?

That's the question you should be answering. Not trying to sell some "self-actuated change awareness" mumbo jumbo. The video literally sounds like an infomercial for a cult.

Sorry for being harsh, but it sounds like you have some cool technology which is unfortunately overwhelmed by terrible marketing.

Permit 6 hours ago 0 replies      
I just want to say that I strongly disagree with the people here who are complaining about your pricing page.

You need to validate that people will pay money for this product, and the quickest way to do so is to ask up front. I really don't buy this "Give it away for free, get them hooked and then staple on paid features" approach.

PG said it best: "Better to make a few users love you than a lot ambivalent."[1]

One of the best ways to find out if people love what you're building is to ask them to pay for it.


wldlyinaccurate 1 hour ago 0 replies      
This reminded me of Wraith, a screenshot comparison tool which The BBC developed for integration testing: https://github.com/bbc-news/wraith
stephentmcm 9 hours ago 2 replies      
I've half built a tool to do this using PhantomJS, and a really half-baked API. The image grab part is easy. The diffing is what's hard... well sort of.

What I tried and what this site appears to do is a straight pixel change detection, which fails to account for how important that change is. Minor things change on a site all the time it's catching major breaking changes that's hard, say a CSS rule change that looks fine on desktop but ruins the site on mobile.

zoidb 4 hours ago 0 replies      
Hey nice! I've actually done something similar myself as a weekend project - https://page-watch.com

Also checkout the following projects, https://visualping.io/ and https://dpxdt-test.appspot.com/

If you are using something like phantomjs to generate website screenshots I wonder how you are dealing with dynamic content. A lot of pages have continuous animations that can screw with simple image diff comparisons. For this reason you may want the option to limit your compare to a subset of the page.

kasparloog 5 hours ago 0 replies      
Monitoring is a good idea. However, pixel-based comparison services are quite pointless for web pages. Banners, dynamic content etc. simply drives spam.

Try Browserbite with its feature-based comparison. There are other regression-oriented tools out there as well that use pixel-based methods as well.

bcjordan 9 hours ago 0 replies      
Very nice! Your CMS integration looks like a fantastic way to mitigate the onboarding pain of most integration testing systems.

Definitely a useful type of test to have and certainly comes from a place of pain. Last year I worked on a bootleg similar project during the YC Hacks eventit was hard to get it to work right.

Recently Applitools Eyes[0] started gaining popularity for CI-based visual testing, I hooked it up to some Selenium integration tests at work earlier this year and the things it catches have consistently amazed me. Catches nearly all of the bugs that manage to slip past the typical unit / end-to-end tests.

One hard part they navigated well has been the interface for being able to review changes, set new baselines, and set a certain area as "ignored". IIRC they even use some fancy computer vision algorithms to handle slight variations in screenshots (e.g. font alignment false positives).

[0]: https://applitools.com/

uptownfunk 7 hours ago 0 replies      
I want to know what this does, the youtube video does not explain clearly in layman's terms.
olivierkaisin 6 hours ago 0 replies      
Great project!

This is really a need for monitoring consistency of UX of any website.

Although I just think you should simplify your pricing model. I don't understand why you are talking about "requests". Who cares about bandwidth today anyway? Just make people pay for the number of pages the frequency of the checks.

Also, you should allow people to set up e-mail alerts when some parts of their website pages change (e.g. payment forms).

I would definitely pay for such product. : )

Gigablah 9 hours ago 1 reply      
Your API documentation isn't public. That's an instant turn-off.
gcb0 8 hours ago 1 reply      
the license plates image is misleading as hell!

for a moment you think it is smart enough to realize subject and background and only show you changes on the normalized objects.... but it is actually just an edited image on the other side to add a clean element for the diff.

bliti 7 hours ago 0 replies      
Your landing page might benefit from using wordpress as an example. I saw the service and immediately thought about how to integrate this into wp. Maybe even turn it into a wp plugin? Dunno. This does seem useful.
joshcanhelp 8 hours ago 0 replies      
This looks fantastic. I was just looking into doing this "manually" with an automated screenshot process for a site I'm refactoring part by part.
bgraves 9 hours ago 1 reply      
Hmm, is this built on top of url2png by any chance? :)
omarchowdhury 9 hours ago 0 replies      
Could use this to monitor competitor's landing pages and see what they split test.
cekanoni 5 hours ago 0 replies      
your ssl is signed by unknown vendor so i wouldn't trust it..
OneTwoFree 8 hours ago 1 reply      
The site shows an SSL warning message. The certificate details says it was issued by "Avast untrusted CA".
Arguments for TPP dont make sense bostonglobe.com
60 points by walterbell  7 hours ago   7 comments top 5
themartorana 1 hour ago 0 replies      
Not to hijack the better points of the article, because it's a good one, but this line is telling:

"The White Houses efforts to portray the treaty as critical to national security simply underscores its inability to make a case for the agreement on the basis of economic benefits."

If you can't make a cogent argument, just flail your hands about and yell "National Security!" You wouldn't dare try to impede national security!

Those two words are what remain of Bush's "you're either with us, or against us" brand of patriotism, but it has a choke hold on the U.S. I cannot understand why otherwise smart people continue to let "national security" dissuade all common sense in everything.

Edit: "Investor-State Dispute Settlements" make me want to throw up my hands and move to Mars. I can't fathom how anyone can accept calling ISDS "national security" as anything but pure, black-tar hogwash.

JabavuAdams 1 hour ago 1 reply      
I'm surprised that the article doesn't spend more time pointing out the sheer arrogance of this, to non-US eyes.

Even the countries who would possibly be signing on to this must be insulted by it. That's not a good place to start.

Nobody else in the world cares about US interests, except insofar as it enriches them and/or prevents them from getting beat up and/or cornholed by friendly, drunk, sometimes generous, often abusive Uncle Sam.

PebblesHD 3 hours ago 1 reply      
The secrecy surrounding the negotiations based on the premise that "We'll see it when it's passed" is absolutely part of the reasons it's been resisted in the way it has. The portions that have been leaked so far seem to suggest it's role is little more than expanding US control over media rights and limiting other countries abilities to produce potentially competing products (Medicines, media etc) which of course means any country with any form of sensible population would want nothing to do with it. Sadly the desires of the population seems to mean little when governments weigh the concerns of big business but still.
aikah 14 minutes ago 0 replies      
Especially the "China is out to destroy us" argument. It's funny how each time there is a heated debate in USA, China suddenly looks it is going to invade USA soon ? Even worse, China might join the TPP in the next future. So enough of "but but China..." bull.

The TPP is a excellent deal for multinational corporations,no question, they wrote the deal, whether it's good for your job or your small business here in USA is a different story. People should be able to see the deal right now, because it will have a lot of direct consequences on their lives. Or Obama doesn't trust people's common sense? or he wants that legacy at any cost?

drawkbox 1 hour ago 0 replies      
China is setting up a 'New Silk Road' [1], not the darknet one but resurgence of their trade dominance of Asia from the past. China is also benefiting their trade partners in ways that the US doesn't always and we should. The original silk road was known for bringing riches to all points on the routes.

China also has presence in the South China Sea where 2/3rds of all trade go through, it is the reason they are adding new islands there as well. CNN recently had this in the news but it is ultimately protection for the trade routes through the South China Sea.

They have also been diplomatically setting up station in Yemen [2] and Somalia [3] along the Suez Canal trade route. So at major points of the water based trade routes, China is owning them or taking control of them.

China is also building a massive trade route through Pakistan to the Gwadar and Karachi ports in Iran and Pakistan, very close to Iraq + India and near Afghanistan.[4] Completely within Pakistan/Iran, it is another route around the South China sea near the Persian Gulf.

The World Trade Organization (WTO) in 2005 left China with huge advantages in exports and currency tools that are smart for them and bad for the US in terms of running trade in Asia etc. We have slipped a bit, largely this is due to short term thinking and overt control of trade partners. We are giving up alot in the TPP because we never really have, we have to convince countries to trade with us for our advantages and theirs, over what China is offering.

Trade agreements aren't always bad. But in the US now due to the control of them they are usually bad for the workers. The problem with the TPP is that corporate riders have attached on in ways that are solely focused in greed, over the workers of the US and protections for US.

You could argue that China lent us the money to get into debt to them to allow them to do this while we were bogged down with wars, unwinnable wars, with force in the Middle East around the same areas. We need more Marshall Plan type liberation through economic advantages for the whole countries involved to be a better option for trading partners. China is winning the game, that is why this is fast tracked but it is also bad for the US internally but the other option is losing more trade dominance.

The Yale article on the new Chinese Silk Road (One Belt, One Road initiative) mentions the core reasoning in this snippet:

Will supporting China's One Belt, One Road, compromise core universal values and high environmental and labor standards? These are key areas where the US can show leadership and remain a keystone of the 21st century global economic architecture. But a keystone must work with other stones rather than stand alone.

It is a pretty easy sell for the Chinese to these countries like Pakistan, Iran etc with us right on their doorstep and without a good economic mutually beneficial plan for the places we 'liberated'. Force doesn't always work but better quality of life always works, always brings more money. We should leave places in a state like Japan or South Korea, not how we left Iraq/Afghanistan/ etc. Now China is also getting defense/military power to contain these areas.

This is a massive world change. We can't change it with force this time, China is everyone's biggest trade partner including ours. It would be better to work it out with them than exclude them. We have to benefit the US and other countries with trade, not take everyone down. China is doing the opposite and the better deal will win.

[1] http://yaleglobal.yale.edu/content/china%E2%80%99s-new-silk-...

[2] http://www.washingtonpost.com/blogs/worldviews/wp/2015/03/31...

[3] http://thediplomat.com/2014/07/after-23-years-china-to-reope...

[4] http://tribune.com.pk/story/896213/pakistan-dismisses-indias...

Servo: The Countdown Continues s-osg.org
121 points by Manishearth  11 hours ago   31 comments top 5
DiabloD3 9 hours ago 5 replies      
Servo becoming part of a modern browser gives me a serious boner. Chrome and Firefox are both significantly working on trying to make sane multi-threaded models, and they often either end up with insane ones, or end up with sane ones that don't perform usefully any better than having left it single threaded in the first place.

I just wish that Chrome would fix performance on OSX. I have no issues on Windows or Android (of course), but OSX it just seems way slower than it should be on a lot of normal tasks.

I mean, literally, the only reason I use Chrome is because of synced tabs, history, and bookmarks built into the browser and having access to that on Android too, purely all the integration into the phone features (I have a Nexus 5).

To hijack my own reply here, where Microsoft is going with Windows 10, if they really hit off, I'd consider a future Lumia model to replace my Nexus 5, because Project Spartan seems to be catching MSIE up to what Firefox+FirefoxOS and Chrome+Android do now.

Edit: Not sure why I'm getting downvoted here. I'm pro-Servo.

pjmlp 5 hours ago 3 replies      
> servo = !!dlsym(NULL, "servo_test");

I just cry when I see something like this.

cgcardona 1 hour ago 0 replies      
It's worth mentioning that getting Servo to build and run on OS X is very straight forward and worked for me the first time.

Here is the github repo: https://github.com/servo/servo

Here is this HackerNews thread rendered in Servo: http://i.imgur.com/6yvrr3V.png

tinganho 8 hours ago 1 reply      
I'm just hoping someone will create a new Electron (used in Atom), but based on Servo instead of Chromium.
monk_e_boy 5 hours ago 1 reply      
How will developer tools work with servo? A plugin?
Rules for Writing Safety Critical Code spinroot.com
29 points by plumeria  7 hours ago   20 comments top 6
erikb 11 minutes ago 0 replies      
I never worked in a safety critical environment, so my ideas are probably flawed.

My feeling says that limiting loops and not using some language constructs can enhance quality that much. Checking and rechecking requirements, having different levels of testing, and most importantly have static and unit test checks on the source code abstraction level has a huge impact, though. Example: Even if you use only simple constructs like if and for you still run into problems with complexity because some problems are complex. Now the complexity simply is spread, which in some regards might make it easier to handle but in other cases makes it much harder to see the dependencies.

TickleSteve 2 hours ago 1 reply      
A lot of these rules are just good practice for general embedded s/w development (see also MISRA), such as fixed upper bounds on loops, etc are intended to minimise dynamic situations and assist analysis.

Just to be clear...Following these rules does not get you any kind of safety related certification.There is a lot more work, both up-front in requirements & analysis, and after implementation to gain any kind of certification.

jacquesm 2 hours ago 1 reply      
In 'C' or 'C++'.

Though some of the rules are portable to other languages.

I'd add: have someone else familiar with the code base look over your code, add tests for your functions, test exhaustively where feasible, document your code and document your reasoning behind the code as well, make it look good, try to avoid being clever.

SCHiM 2 hours ago 1 reply      
However from the top of my head I can give you one example that is likely used in very security-critical applications that also uses goto:

The linux kernel.

The kernel coding conventions actually state that this is because over-zealous nesting is more harmful than using goto statements.

>The rationale for using gotos is:- unconditional statements are easier to understand and follow- nesting is reduced- errors by not updating individual exit points when making modifications are prevented- saves the compiler work to optimize redundant code away ;)


chopin 2 hours ago 2 replies      
I am not sure whether I understand rule #2 correctly. My main use case for loops is iterating over an array or a list of statically unknown size, therefore the loop is limited to the actual size of the array or list. Would that count as statically provable? At least in Java, these cannot hold more than 2^31 elements for the standard library collections. For this use case, would it be required to have a hard-coded upper bound additionally?
lordnacho 54 minutes ago 1 reply      
What about using smart pointers? There's a whole class of potential errors related to using raw pointers.
Death on the Steppes: Mystery Disease Kills Saigas nytimes.com
14 points by igonvalue  4 hours ago   discuss
Ask HN: My free app has gone slighty viral looking for ideas to monetize it
80 points by Rabidgremlin  10 hours ago   108 comments top 46
kriro 4 hours ago 4 replies      
I'd approach this differently and from reading your replies you seem to be a fairly laid back (non "cutthroat") guy so this might be interesting for you.

Use it as a fun experiment to see how much you can grow it not how much you can monetize. Formulate some assumptions and test them. I'd personally pick one of the countries and see if I can push installs in that country hard (might be difficult due to language issues).Try to figure out how people learn about your app and install it. Figure out what phones it is installed on and write a blogpost on using your app on that phone etc.

55k active users isn't bad. If you keep on growing someone will get interested even if you didn't monetize before (possibly even because you didn't) especially since it's not a "fad app" but something sustainable as long as there's low resource phones.[worst case you can use it if you ever want to apply at Facebook]

tl;dr: use it as your private growth-lab and learn a lot :)

aaronbrethorst 10 hours ago 7 replies      
Unlikely to succeed. Your users won't want to be monetized and they're from countries that are relatively unmonetizable. You don't say what you do for a living, butpersonallyI'd slap this on my resume as a 'look at the awesome user base my apps have had' sort of event, and move on. Great way to gain better leverage for the next job move or raise request, but not likely to be more than that at present.
polyvalent01 4 hours ago 3 replies      
Hi OP I'm from morocco and I can tell you that NOBODY in Morocco will pay your app. Why ? I'll tell you why.

Here in the 3rd world countries we don't have credit card unless we get a job, and when I say "get a job" I mean 28 and up . Morocco is very different from Europe and US because we don't have unemployement and just to make a living is really hard.

Also Piracy here is something commun because our ISP ( and we have only one lol who fuck the market with their High price and low value) Doesn't block torrent, as long as you stay out of Illegal stuffs...

Also even if I have a credit card at 21 ( I worked in a call center in the last summer so I can afford it) I will never lose money on apps. First: I'm poor Second : We only have 10 000 Dirhams ( 900 Euro ) to spend in a whole YEAR. Wich means we're very careful on what we spend money on.

So the best thing I can tell you is to add a banner and one or two Interstial ads and NOBODY will bat an eye .

Hope I gave you an insight OP :)

BinaryIdiot 10 hours ago 2 replies      
This is tough. When webOS was announced I got into the early Palm developer's program and created an application. It was kinda neat but also not incredibly complex. After the Pre was released within about 6 months it had over 100,000 downloads (which, for a new OS and device, seemed kinda awesome!). It was a free app but I thought I could try to monetize it a little.

First step was to try ads. It went from highly rated to about 3 stars because everyone hated the ads (understandable). I tried putting them at the top, bottom, middle; nothing worked at all.

There were no in-app purchases for webOS (or really any platform at the time) so I did what everyone else started doing: when they launched being able to pay for apps I provided my app for $.99 with no ads. After 2 years of running I made $9.

Essentially I destroyed the user-base my app initially had by trying a couple of ways to monetize them that provided poor user experience. I'm not sure what the best solution is here but don't make my mistake and worsen your user experience to make money; it won't work.

FYI for anyone curious my app on webOS was a take on the tip calculator. I know I know "why would you try to charge for a TIP calculator!?" but I thought the spin I had was novel, you could rate different parts of your restaurant experience to get an exact amount to tip rather than dealing with percentages at all (it only showed you the percentage after it calculated the tip). I had done a ton of tip research at the time and thought the idea might be worth something (plus I was young and dumb). It even had bill splitting! But yeah in the end I really shouldn't have charged for it I mostly wanted to experiment to see if I could monetize it and I ended up completely destroying it. http://www.webosnation.com/dumb-waiter-free

gabchan 8 hours ago 2 replies      
SocialLite is a great name btw.

Monetization via end users is not realistic. This is my hypothesis regarding your user profile: (1) low-income or no-income aka cost sensitive, (2) possibly bad mobile data infrastructure, (3) pay-as-you-go mobile data or limited wifi access.

Your app is valuable because it is a REPLACEMENT for the company's real app, because the real deal (as you put it nicely) is too large.

I would perhaps develop clones of your app for other social networks, and have a constellation of SocialLite apps for Twitter, Instagram, Pinterest, Tumblr, etc...


Because the value is in how lightweight you are but still be able to satisfy end user needs. Do not add ads, or in-app purchase bullshit. Your users don't want that. And customers are gods.


Because you are collecting DATA. Usage patterns and quantifiable habits. The companies would be interested in that. Even just Facebook might be interested in what stats you have now, and having data on their frienemies adds proportionally more value.


Before you write another line of code, please reach out and get some feelers to see if the companies indeed want data and what data they are looking for. Since you are in developing markets, and companies want to expand there, you are providing a unique and rare insight into those markets. Data driven insights are better than anything else.


I would not survey the users. Bad UX (specifically bad information timing) and whatever little data you ascertain will not be actionable anyway.

mbesto 2 minutes ago 0 replies      
Make a pro version with a few extra features and sell it for $2.99.
fabiandesimone 31 minutes ago 0 replies      
Why not put 'App Recomendations' messages that drive installs for other apps?

There's a ton of CPA networks that pay anywhere from .5 to $3 for an app install.

kirualex 6 hours ago 2 replies      
I had the same idea 4 years ago and did the exact same thing for several apps. This was a bad idea : https://medium.com/@kirualex/an-android-developers-nightmare...

Google content policy is now very clear :Do not post any applications whose primary function is to:generate traffic to a website; or provide an overview of a website that you do notown and you do not handle (unless you have permission of the owner / administrator of the website).

eddiedunn 42 minutes ago 0 replies      
Kickstarter campaigns often charge people extra money for getting access to Alpha and Beta builds. People are impatient, many want stuff sooner rather than later, so they pay for it.

You could offer a modified version of this; allow premium customers access to new features earlier, but roll out the updates to your free subscribers eventually as well. After a delay of 3 months perhaps?

It will gently encourage people to upgrade, but those who don't want to pay won't feel cheated as they will get the features eventually as well.

lsiebert 10 hours ago 0 replies      
Don't put third party advertisements in. If you are going to do any advertising, come up with a second project that might be of interest to your demographic, but that costs money, and advertise for your own product.

I'd consider some sort of soccer score app that integrates with FB.

drawkbox 3 hours ago 0 replies      
With a free app you have to have your monetization in before launch. But this is a great platform to launch other apps from. Apps even next to a popular free app get more visibility/discovery. Many companies launch a free app designed solely for users to help drive pay app usage.

Donation is probably the only option as advertising for those areas aren't as high in payout. Don't be sad by the letdown you will get from donation though, it is always way lower than expected. Ad supported apps also don't really get that much money.

The only successful app strategy is to have quality apps and as many as you can support with quality levels.

qwz 59 minutes ago 0 replies      
Looks like the same kind of users as Opera Mini which has high number of users in Indonesia, India, Pakistan etc. They face similar problems as you do. Many users which don't have much money.

Idea 1) Sell it to Opera SoftwareIdea 2) Do like Opera and sign deals with mobile network operators to include operator contentIdea 3) Sell Internet access through your app. Internet access is normally sold by hour in these countries. Sign deals with operators and similar.Idea 4) Advertising in app

onuryavuz 5 hours ago 0 replies      
Actually there is an official app published by Facebook, for size-sensitive users. It's called Facebook Lite and here is the google store link : https://play.google.com/store/apps/details?id=com.facebook.l...
cvitale 7 hours ago 1 reply      
Mr slightly viral,

You priced your app at zero. It became a success. Monetizing your app now will probably make it less so.Rather monetize by building good will with your customers (brand) and applying lessons learned towards development of your app2. If it's good enough you can charge for it.

garagemc2 1 hour ago 0 replies      
I'm sure everyone else has gone through the pro's and cons of different monetisation and product strategies.

But having looked through the thread, I don't believe anyone has asked you to think about Why the app is getting traction.

You can come up with your own hypothesis or you can ask your users.

Once you've understood why, you'll be better placed to take the next step. Whether that involves monetisation, creating clones, developing the app, not developing the app - that is up to you.

Tl;dr Find out why users like your app and try to strategise based on that.

sdernley 2 hours ago 0 replies      
Congratulations on the success of the app!

When i've been in similar situations i've tried to look forward and not back. By that I mean, if it's getting a lot of downloads then let the people who have already downloaded it have it, don't change their experience by adding adverts in or damaging parts of the experience. Charge for new people to get the app. Saying that, I've never had it with as many people already downloaded the app, but i'd like to think i'd still do the same thing.

I have an app that I originally charged for and it got very little downloads, I made it free for a while and didn't pay much attention to the downloads, went back to it at a later time and noticed it had a lot of downloads so I started charging for it just to see what would happen, I expected to make it free again within a week due to no downloads. Downloads obviously dropped a bit, but still kept a pretty consistent level and have done ever since. I make a point of always improving the app though, so maybe that helps too but I just think it comes down to timing and having those previous downloads could help, it seemed to help me.

I'm not sure if you can turn a free Android app into a paid one though, I don't think you used to be able to, so that might all be pointless and you'd have to make a new id for it, but you've proved people definitely want it.

Whatever you do, good luck. I'm sure having a high downloaded app will help you at some point even if you don't manage to do as much as you want with this one. I hope you do.

jmbrook 3 hours ago 0 replies      
First of congratulations on the app, it is fulfilling a real need.

You have cracked the first problem of getting people to download + use +care about the app.

I like the idea of doing the survey however from my experience (we did a paid for Google Customer survey) our users want more content and for price of free which wasnt hugely useful.

Personally I think you have three easy options:

1. Add some low level not too obtrusive adverts in (you will get a nice trickle of money in)

From my own experience of putting adverts into a util app (https://play.google.com/store/apps/details?id=com.teazel&hl=...) no-one minds at all. The key is to not go overboard. We have banners that don't refresh too often, disappear if they going to draw over a dice. The number of apps I see show full screen adverts at start up, every page transition etc - all very icky.

2. As others have said try and grow it and use it for Resume/CV building. My one reservation on this is make sure you actually try and capitalise on it. Im reminded of friends staying in awful jobs due to the training/experience and years later never really harvesting the rewards.

3. Use it to cross promote another app (either by yourself or sell the space). Getting an app to be downloaded is so hard now having this to kick start the next project is a great de-risker.

I would go for option 1 or 3 depending on whether you have other apps in the pipeline.

As an aside is this lightweight wrapping of a webapp model work for other providers? LinkedIn etc?

ceejayoz 10 hours ago 1 reply      
Be mindful of what Facebook's lawyers will think of you monetizing their logo and their website.
rnovak 4 hours ago 0 replies      
I am/was in the same situation as far as popularity goes with my desktop application (for OSX), and I personally went the route of not monetizing at all. To me, the knowledge gained through every feature I added and every bug I fixed is/was more valuable than the money I could have made.

Then again, I have a great paying job that I love, and I primarily built it because I couldn't find a similar application with the features I was looking for, so other people finding it useful is just a bonus. Plus, it's a great way to show that I have passion for development outside of work, and that I'm continually trying to improve myself as a programmer/engineer. I even provided detailed Arch/Design/Req docs in the github repos, just in case anyone was interested in looking.

Of the options listed in this thread, I like the idea of adding an "in-app" purchase for the feature you mention gets requested a lot (photo uploads I believe). The knowledge that will give you is immensely valuable (being able to turn features on/off in the same application), if you don't already have that built in.

Anyway, that's just my opinion, but you should do whatever you think will make you happy.

angryasian 6 hours ago 3 replies      
I'm not accusing you of anything, but

Tinfoil is a great app thats similar. Also free and open source - https://play.google.com/store/apps/details?id=com.danvelazco...

Gustomaximus 10 hours ago 1 reply      
Nice app. Developing countries love their saving data (I used to work with an app in a similar vein). In your shoes Id likely move forward in 3 stages;

1) Bug Fix - if you can build momentum on growth your really onto something. Given the 80% inactive rate, have you looked at why people are uninstalling (I saw a bunch of no photo upload button on my quick look)? Improving scale if probably the best way to make money if you don't really need the cash now.

2) Insert reasonably unobtrusive ads and see how they go. Given the countries involved you'll be surprised that even with a large number of users you're not hitting big money. Possibly try a few different ad placements to see the user experience vs. clicks vs. payments.

2) Once you have ads and know how many clicks you are getting, look for local opportunities for the bigger country(ies). Things like sponsorship of affiliate/offer type deals. These should pay more but come with a real time cost.

3) Once you have a view how much a customer is worth, decide if you want to take the cash out or re-invest back into growing the app. Ideally if you can spend $X on recruitment and get back $X+Y you should chase growth. If not, enjoy riding the organic wave.

Regarding the poll, I'd not bother. What people say and do are often very different. I'd be more inclined to test ads and placement for real response. Monitor for feedback and possibly make a ad free version if people want.

I've heard donation buttons don't really work.

Adding additional social support sounds good but at a price? Not sure there. These markets are super cost conscious so I'd personally look to focus on growth first and secondly monetising the user at no cost to them.

Good luck

blazespin 5 hours ago 0 replies      
Rather than monetize, I think instead you should try to get more people to install it. Make it better. Add features to block ads or something. Clearly you've built something people want. Find a way to engage with your users and build more trust with them. Your next app will be quite popular with them, I'm sure.

You're trying to monetize too early. Get real traction first. A million dollars isn't cool. You know what's cool? A billion dollars.

jcoffland 8 hours ago 0 replies      
Many apps or softwares are successful because the price is right. Often the right price is free. You need to consider if your user base even has money to give you. Your best bet is to use traffic from your current app as a way to sell another related service.
makuchaku 8 hours ago 0 replies      
Script the build & make such tiny apps for all popular permission hogging apps with websites. Then cross-promote them within your app.

This is what I would do :)

pratyushag 3 hours ago 0 replies      
Given your motivations and comments, I would recommend that you have a whatsapp like subscription in place. One can get around paying for the subcription by inviting friends. For best results, make it easy enough to select all for the invite [you will soon realize that you'll get most of your users from such people who don't mind inviting a friend to an app they like a lot]. At some point in the next 1-2 years, you would likely get to 1 million downloads!
lucaspiller 6 hours ago 1 reply      
I have an app in the Google Play store, it has around 1,500 active installs and I decided to do a bit of an experiment last year by releasing a paid pro version. It was exactly the same, it just had a different colour icon and 'Pro' branding. I put the price at 99c/99p, and put a link to it in the free edition description (the descriptions were the same other than that). I was pretty surprised when people actually bought it...

I think I made about $5 before I realised after a couple of weeks, and then I took it down. The app hadn't been touched for a few years and wasn't the best quality, so I didn't feel happy for basically scamming people. I was considering doing the same for a donate version, but wanted to improve the app first - which I never got around to.

I think you could get some income by doing something similar, but it's very unlikely to replace your main income.

fpvracing 10 hours ago 1 reply      
Looks like a cool app and you've got some great reviews.

I would not add advertisements as you will risk damaging the good relationship you currently have with your users. Try adding a donation button and just see whether it brings in enough money. Adding support for other social networks also seems like a good idea, but a lot more work.

I'm actually in the process of developing my first Android app for our community at https://fpvracing.tv. Any tips / tutorials you would recommend?

ggurgone 7 hours ago 1 reply      
Here's how you could play it:

1) Play dirty: serve high resolution media (pic an videos) to the users - this results in more data downloaded = costs more money to your users. Here is where you ask them to pay a fair monthly subscription that would cost them less than $x-internet-provider-money (you can make tailor made plans depending on the stats)

2) Make it faster for who pays! At the very top of the page you could add a speed indicator (something like a thin progress bar) to indicate the speed of the page.Then make one of the views (the profile page for example) super fast to tease your users! and the ask for upgrade to premium to get all teH things fast :)

No matter how you play it I would "re-brand" it and remove any reference to the FB UI - which I guess is (c) Mark Boy

bond 3 hours ago 0 replies      
My opinion is not to listen people telling you not to put ads.Remember, your demographics is not first tier so that advice doesn't apply... You'd be surprised what a banner or an interstitial can bring on those countries....
raverbashing 3 hours ago 0 replies      
Don't monetize the app, but build from the success of it.

You have an App with 240k installs, that's very good in a CV or when pitching your services.

This demographic is not going to pay you, sorry.

Now, developing apps that are light and work in older phones can be a marketable skill.

ranrub 1 hour ago 0 replies      
Is this really just a webview that loads m.facebook.com?
pbreit 7 hours ago 1 reply      
How about the WhatsApp approach: first year free, then $0.99 per year?
nait 5 hours ago 0 replies      
You could try adding a "Social Lite Deals" page where you put affiliate offers (e.g. stuff with reduced prices from Amazon).

This way you provide some kind of additional value and don't risk offending your user base. Granted it won't be as effective as ads but perhaps it's a good starting point to figure out what your users like and accept.

kneonx 8 hours ago 0 replies      
You could add a 1 second splash count down whenever they open the app from multi tasking, and a simple payment can disable that. It's not an ad. Just a countdown timer with an unlock feature. For a typical user, it wont be that big of a pinch, but for power users who cycle between apps and check back it could be worth monetizing.

Once again you're not putting ads, you're just exercising your right to monetize something you built ;)

OR if there are premium features you can push out that are not ad-removal related you might stand a chance at converting 1% of your users (freemium model)

dutchbrit 4 hours ago 0 replies      
Don't do ads, people will uninstall it in a jiffy. Create a second app, call it Social Lite Plus or something, and have some extra options - bit of a freemium version, but not sure if that's a possibility?
crdoconnor 6 hours ago 1 reply      
Add an upgraded app that lets users redirect their traffic via servers you control. If they installed your app for privacy reasons, give them a reason to pay you for more privacy.

If Turkey is very popular that tells me that your users might want to conceal the fact (from their government) that they use facebook at all.

emilioolivares 10 hours ago 1 reply      
This kind of happened to me. I've tried building serious apps with limited success and traction. I'm a huge reddit/imgur fan so a built a hobby site for myself using reddit's api to browse through their images: http://www.flipmeme.com. Currently gets 100k uniques per month, can't monetize!!! In other words, the stuff you really work on doesn't get anywhere, random stuff you build as a joke suddenly takes off?!
aniketpant 8 hours ago 1 reply      
I was looking around and I found https://play.google.com/store/apps/details?id=com.facebook.l... which comes from Facebook itself. Strangely it is incompatible with all my devices and I think this is due to a play store location based restriction (I am based in India).
mastercoms 7 hours ago 1 reply      
When I think light, the last thing I think of is ads. Ads will make your app feel bloated to users.
z3t4 6 hours ago 1 reply      
You can take the opportunity to build your brand, or someone else's. Gaining peoples thrust and building a reputation is hard, but very critical! Fifty thousands active users are worth about one million dollars.
antigirl 4 hours ago 0 replies      
Wouldnt the users get a better experience using the browser rather than using webview wrapped site?
maerF0x0 4 hours ago 0 replies      
Do the whatsapp thing. Free for 1 year. $1 afterwards. Its affordable even in all those countries.
abannin 4 hours ago 1 reply      
Congrats! This is really awesome. You've found some amount of product-market fit, and that is really really amazing. I think you should keep going, as this is when things start to get hard. You've cleared a few hurdles, and now you need to clear some very different obstacles.

From the countless hours that I've spent trying to figure out how to get users to give me money, I can confidently say that a surveying your users about monetization is the worst data you will ever see.

I can also say, with 200% confidence, that ads are not the right decision at this point. Here is why:1) They aren't your users. These are FB users, and if you start showing ads to them, FB will view this as stealing ad space from FB. Not a good spot to be in.2) The geo distribution seems pretty clear that the light weight solution is a compelling feature. Ad SDKs are notoriously heavy on the binary, sometimes 20MB. Ads also use a large amount of data and are often slower than everything else. Most web pages could load in a fraction of time if they dropped the ads. So, putting in ads seems to kill the biggest feature of your app.

I don't buy the argument that you can't monetize that geo distribution. It's true that those geos are overlooked by larger companies, but that also means less competition. Just know that you're fighting for low ARPU users. Whatsapp used this strategy wonderfully. When their competitors were fighting over iPhone penetration in the US, they were building for feature phones in similar geos. They also kept the price point low, keeping in mind they had lower ARPU users.

I suspect that your best solution would be to find a compelling in-app-purchase (IAP). To do this, you'll need to start knowing everything about your users. What features do they use? What features do they not use? When do they use the app? What do they want to accomplish with the app? Remember, Line started selling stickers when everyone could use emotiacons. Sometimes the winning business model is the thing that no one thought to try or everyone thought was too dumb. What is FB missing from the experience that you could add? I've always been impressed at how user's actions can be the opposite of what they say. Your users will reveal their intent by what they do, so watch them very carefully.

I suspect a very telling analysis would be to start comparing users who hit the day-7 mark and leave vs those who hit the day-7 mark and stay. My guess is that you'll start seeing some patterns about how retained users are interacting with the app, and then double down on that.

As a side note, your DAU to installs ratio seems to imply poor retention for a social app. This may be because the growth is targeting the wrong type of user. Regardless, this is a number that you'll probably want to get to know very well. If you do have lower-then-average retention, find a way to turn it into a strength with other numbers that are really impressive, such as engagement.

This is really, really awesome and you should be proud of what you have accomplished. The next stage of growth will be harder to scale, but the bragging rights are a few orders of magnitude higher up there. Keep it up!

zkhalique 5 hours ago 0 replies      
Yes, add google admob and facebook audience network ads, and a way to turn them off
unicornporn 4 hours ago 0 replies      
If you do this I suspect most users will move to "Tinfoil for Facebook". It does exactly what you describe and is popular and open-source.
codecamper 2 hours ago 1 reply      
You spent an hour to write an app? ok.
Open-source ambient physical display that visualizes weather conditions tempescope.com
14 points by gedrap  4 hours ago   2 comments top 2
jurasource 1 hour ago 0 replies      
My first thought was "um, isn't that a window?" :)
meesterdude 1 hour ago 0 replies      
The idea is good, but the implementation is boring. Pair that tech up with a terrarium, and you've got something. Add sunlight and clouds and you could end up with something fairly artistic.

That it mimics the outside weather is gimmicky and misplaced. That's a sidefeature, a checkbox; thats not what really matters. Something that looks cool that people will buy is.

BrowserRemote, debug your user's browser remotely via Chrome DevTools github.com
12 points by auchenberg  5 hours ago   1 comment top
joshribakoff 22 minutes ago 0 replies      
I created a similar proof of concept recently. We need to inspect the webpage displayed on a Chrome based "kiosk" running behind a firewall. We have an existing socket (or socket IO binary) connection, and my proof of concept "attaches" the Chrome remote debugging port to listen on the socketIO connection - See the youtube video in the readme to see it in action. https://github.com/joshribakoff/devtools-proxy

The tool linked in the OP looks a lot more user friendly, but perhaps my example code will be of use to someone who wants something [overly] simple.

How Large Are Global Energy Subsidies? [pdf] imf.org
15 points by anigbrowl  5 hours ago   3 comments top 2
nkoren 1 hour ago 0 replies      

"Coal [...] is the biggest source of post-tax subsidies, amounting to 3.0 percent of global GDP in 2011 and rising to3.9 percent in 2015. [...] Petroleum is the next most heavily subsidized product, [...] remaining at 1.8 percent of global GDP in 2015 despite declining petroleum prices. This is followed by natural gas, [which] is onlyabout one-third of that for petroleum. Last is electricity, for which the projected post-tax subsidy declines to just 0.2 percent of global GDP in 2015."

Solar, wind, etc. are presumably subsets of the electricity subsidies, and are so negligible as to not warrant a single mention in this report.

Shivetya 1 hour ago 1 reply      
So basically post tax subsidies are anything they can throw in there to make the fuel source look worse than another? That and they want to clump together all users of particular energy types so as to eliminate areas of the world where such imbalances don't exist, or don't exist at the severity they desired for their report.

The gist of this report is that consumers are underpaying for power and that if only people paid more taxes on energy there would magically be more money for health, welfare, and education.

Just ignore the post production subsidy values, its as real as unicorns and the Easter bunny. The odd part is many of the costs they are trying to attribute to post taxes mostly occur in the developing world for who are least capable of paying for it. As in, the "West" has extensive controls over pollution from coal and petroleum but that is not the case elsewhere.

Set text on the web to a baseline grid with Sass and rems sassline.com
20 points by kjannis  5 hours ago   2 comments top
espadrine 51 minutes ago 1 reply      
The page is not very in-depth and the link to a promised blog post does not go to a blog post. Is there something missing?
Show HN: Ruby gem to scrape a web page github.com
12 points by daviducolo  5 hours ago   1 comment top
nathan_f77 1 hour ago 0 replies      
Good work, but you might not have heard about Mechanize: https://github.com/sparklemotion/mechanize
Stonebraker Explains Oracle's Obsolescence, Facebook's Challenge barrons.com
33 points by mooreds  10 hours ago   7 comments top 5
nl 57 minutes ago 1 reply      
Look at Facebook, it is one giant social graph, with the problem of how to find the average distance from anyone to anyone. You can simulate a graph as an edge matrix, and a connectivity matrix in an array-based system, and you model graphs in a table system, or you build a special-purpose engine to implement the graph directly. All three are being prototyped and commercialized, and the jury is out whether there is room for a new graph engine or if one of the other technologies would be good enough.


So I'm dealing with this problem. There is nothing out there.

Neo4J doesn't really do in-graph processing[1]. BlazeFB/OrientDB/RDF Stores all are similar to Neo4J

Pregel/GraphX/Giraph are graph processing engines, but lack property stores.

I want a single system that does both. I want to run PageRank (etc) and query-by-property on the same system.

Titan was promising, but they stopped working on it when they were bought.

I'm surprised no one is fixing this.

[1] http://neo4j.com/blog/categorical-pagerank-using-neo4j-apach... note this bit: "I can scale each Apache Spark node to perform parallel PageRank jobs on independent and isolated processes all consuming a Hadoop HDFS file system where the Neo4j subgraphs are exported to." (ie, Spark runs against HDFS, not Neo4j)

bane 1 hour ago 0 replies      
The linked profile on MarkLogic is quite good. [1]

I remember them from ages ago as basically an XML focused database. I'd see them at trade shows with a small booth. They had interesting technology but had very engineer-y marketing and not a lot of customers. My company had been on the lookout for such a technology and IIR our engineering team checked them out for a bit, but they weren't a great match for our product and we ended up using dtSearch instead. [2]

In the last year or two, I've started hearing MarkLogic show up again all over the place and wondered what was going on. Turns out they got new leadership (Gary Bloom) and have been making a big push to grow. It's funny how that happens, I wonder how many other serviceable companies with decent tech are hiding out just waiting for the right CEO to come along and push them into the spotlight (I'd also add that 'XML' is no longer one of their marketing keywords).

1 - http://blogs.barrons.com/techtraderdaily/2015/02/13/oracles-...

2 - http://www.dtsearch.com/

arjunrc 2 hours ago 0 replies      
According to the article, there are three strategies - Traditional Row based DBMS, Column based ones (Vertica, VoltDB) and MapReduce/Hadoop.

My current employer is making the switch from Row based to Hadoop - which I feel is because of hype & not justified technically, given the size of our cluster. The goal is to reduce speed of data delivery to clients, but I believe a column-based DBMS with an optimized ETL, would be the way to go.

Wonder how it'll look like in 5 years & if others companies' IT are buying into hype too.

threeseed 2 hours ago 1 reply      
I agree about Oracle's lack of a strategy that incorporates Hadoop is definitely going to hurt them. With the addition of Spark the Hadoop platform is looking like being the first choice for analysing data sets whether small or big. And whilst I am sure SQL has and will continue to be a major part of that it won't be the only approach. There will be R, PMML, Python, Scala and a whole lot more.

That aside Facebook having a buy versus build decision to make seems pretty strange. What would they even buy given that Cassandra and HBase which they created are two of the most scalable databases right now. Strange observation.

ExpiredLink 3 hours ago 0 replies      
Stonebraker and his predictions - legendary!
Toyotas Unintended Acceleration and the Big Bowl of Spaghetti Code (2013) safetyresearch.net
133 points by UberMouse  12 hours ago   111 comments top 19
hliyan 10 hours ago 8 replies      
This is appalling:

 Toyota had more than 10,000 global variables. And in practice, five, ten, okay, fine. 10,000, no, we're done. It is not safe, and I don't need to see all 10,000 global variables to know that that is a problem, Koopman testified.

 Toyotas failure to check the source code of its second CPU, supplied by Denso even as executives assured Congress and NHTSA that the cause of UA couldnt be in the engine software

 He was critical of Toyota watchdog supervisor software to detect the death of a task -- design. He testified that Toyotas watchdog supervisor is incapable of ever detecting the death of a major task. That's its whole job. It doesn't do it. Instead, Toyota designed it to monitor CPU overload, and, Barr testified: it doesn't even do that right.

 Barr also testified that Toyotas software threw away error codes from the operating system, ignoring codes identifying a problem with a task.
When the news first broke a few years ago, given Toyota's reputation for quality and process, I thought this was an American industry lead witch-hunt of a Japanese competitor. But if this testimony is correct, what Toyota engineers have done is unforgivable.

thaumaturgy 10 hours ago 0 replies      
There are a bunch of neat comments from past threads about this if you search HN for "Michael Barr":

"On a cyclomatic-complexity scale, a rating of 10 is considered workable code, with 15 being the upper limit for some exceptional cases. Toyotas code had dozens upon dozens of functions that rated higher than 50. Tellingly, the throttle-angle sensor function scored more than 100, making it completely and utterly untestable." https://news.ycombinator.com/item?id=7711771

"For example, http://www.edn.com/design/automotive/4423428/Toyota-s-killer... quotes Barr's claims: 'Toyotas electronic throttle control system (ETCS) source code is of unreasonable quality.' 'Toyotas source code is defective and contains bugs, including bugs that can cause unintended acceleration (UA).'" https://news.ycombinator.com/item?id=8906513 and the linked article has a link to slides which are enlightening)

A number of comments at https://news.ycombinator.com/item?id=6636811, "Toyota's firmware: Bad design and its consequences"

meesterdude 8 hours ago 3 replies      
So, take this into account, and add in self driving cars. The complexity involved in these, and the coordination required, is nontrivial and its clear from the article they do NOT have a good handle on things.

I mean, most cars do seem to get around OK, so I'm partly amazed that under the hood, things could really be so scary. But we can't be lazy about adding complexity and systems, especially as more faith is placed on them.

That this is not NASA grade code (or anything close) does not give me any warm fuzzies. It reeks of unprofessionalism, greed, and laziness.

There needs to be a sane-software assesment. People rely on products with an ever increasing amount of source code - it would be interesting if a third party could come along and certify that a given codebase is not a big scary unmaintainable mess; not to say there won't be bugs or issues, but that these guys are at least trying to make a well designed system, and aren't doing a bunch of crazy stupid things.

yaakov34 6 hours ago 3 replies      
This issue returns to Hacker News and to public consciousness every few months, and each time there is something missing: namely, some kind of direct proof that an actual failure of this software resulted in unintended acceleration, anywhere, ever. Let alone a case of runaway acceleration which the driver is unable to stop with the brakes (requiring a simultaneous brake failure). Since the accelerator pedals in these Toyota vehicles have been pressed no fewer than tens of trillions of times in recent years, that's not an appalling safety record at all. In fact, stuck pedals (whether due to bad lubricants or rolled-up floor mats) are many orders of magnitude more likely to cause stuck throttle than software failures, while runaway vehicles (ones with brakes not working either) are generally caused by "pedal misapplication", i.e. stomping on the gas instead of the brakes.

The fact that software has an execution pathway leading to something bad does not mean that this pathway can ever be entered, since in a closed realtime system like this, it is not possible to receive every combination of inputs, unlike in a system loading user data from a file. This is not to say that Toyota shouldn't clean up and verify its code, but the moral panics over what this code says about programmers, the human condition, Japan, etc. etc. are unwarranted.

Quote from http://en.wikipedia.org/wiki/2009%E2%80%9311_Toyota_vehicle_...:

On February 8, 2011, NASA and the NHTSA announced the findings of a ten-month study concerning the causes of the Toyota malfunctions of 2009. According to their findings, there were no electronic faults in the cars that could have caused the sudden-acceleration problems.

ilitirit 42 minutes ago 0 replies      
Software that can modify any aspects of a vehicle's handling should be subjected to a higher level of testing and scrutiny than things like airbags and safety belts. A faulty cruise-control component is demonstrably more dangerous than a faulty safety belt.
plumeria 9 hours ago 0 replies      
Here are the slides Barr used in his presentation: http://www.safetyresearch.net/Library/BarrSlides_FINAL_SCRUB...
kensai 5 hours ago 0 replies      
"In 1998 that standard had a Rule No. 70 called -- I don't remember the exact language. But function should callthemselves. And the rules basically are the same inbut they changed the numbering system, so in thestandard this rule, same rule is No. 16.2. So thisviolation of the MISRA C rule."

"What was NASA's view about this recursion? A So NASA's view, NASA was concerned about stack -- possible stack overflow. They had a couple of pages devoted to it, about five pages. I pulled some quotes here. Recursion could exhaust the stack space leading to memory corruption and run time failures that may beYes. In what way? The stack can overflow due to this recursion in the Camry. And create memory corruption? And that would create memory corruption, that's difficult to test -- detect in testing."

Man, some elementary stuff here. They changed the specs numbering and did not update their manuals as well as forgetting that recursion in very costly in memory and could overwrite the stack... Jee, these are things a C programmer learns from day one, even in CS50...

hackuser 7 hours ago 1 reply      
In the 1990s an engineer for one the U.S. automakers told me that the code in their cars was a black box. Nobody knew how it functioned; all they could do was watch the input and output, and add patches as needed to modify the output.

Maybe the engineer was talking about code for a specific component, but perhaps Toyota's software isn't unique.

JabavuAdams 1 hour ago 0 replies      
Please edit the title to read "Toyota's", not "Toyotas".
btilly 10 hours ago 2 replies      
Please add (2013) to the title.

People may have forgotten this because it was in the news a few years back. But Toyotas randomly experienced "unintended acceleration" due to software bugs.

Many reported incidents were undoubtably due to the problem that people in a panic can step on the wrong pedal and will misremember what they did. Others were due to a floor mat that could jam the pedal. But some were Toyota's fault.

_ati 9 hours ago 0 replies      
Similar to the aerospace and medical may be there should be strict regulations in terms of processes to be followed for development in the automobile industry also. Usually in medical, failing the audit would restrict the producer to sell the product in market for 1 year. May be something similar could be enforced in automobile industry also. Ofcourse it might increase the cost of cars but atleast they will be lot more safer.
userbinator 10 hours ago 4 replies      
Things were so much simpler when the only problems that could cause unintended acceleration were mechanical in nature. A broken return spring, seized linkage, etc. My daily driver has a mechanical throttle (although it is electronically fuel-injected), and honestly I can't see much point in "drive-by-wire" for cars.

But, on the other hand, even despite so many possible bugs, AFAIK no one has been able to demonstrate one instance of unintended acceleration even with extensive testing.

bliti 9 hours ago 0 replies      
These are safety-critical systems. It still is mind numbing that the quality of the code is so bad. After this came out, I've assumed all modern fuel-injected Toyota's suffer from the same lack of safety. I don't think other automakers may be better.

I own a Toyota, but it has a mechanical throttle body. :)

bootload 8 hours ago 1 reply      
"Defects in the cars electronic throttle control system (ETCS) were directly responsible for the Camrys sudden acceleration and resulting crash." [0]

I couldn't find an exact description of how the driver crashed. Was it using the on-board cruise control or normal throttle use? Never use the cruise control. Must ask when I get my car serviced if it has electronic or mechanical throttle body cf @bliti

[0] http://www.usatoday.com/story/money/cars/2013/10/25/toyota-s...

swang 10 hours ago 1 reply      
So many questions remain...

How do I tell which Toyotas are affected? Do they all have these problems? What, if anything, did Toyota do to fix their software engineering processes?

I ask because my parents have a 2005 or 2006 Toyota Sienna, and I don't feel very comfortable with them driving it now.

PhantomGremlin 9 hours ago 1 reply      
There is, to me, a more interesting question:

If not Toyota, then who? Which auto manufacturers do it right? And is there any public evidence to support that? If not, then I'm probably just as "safe" or "unsafe" in any other brand of car as in a Toyota.

michaelfeathers 8 hours ago 3 replies      
> Toyota had more than 10,000 global variables. And in practice, five, ten, okay, fine. 10,000, no, we're done. It is not safe, and I don't need to see all 10,000 global variables to know that that is a problem, Koopman testified.

I wonder why people want to believe 5 or 10 are okay.

tulb 7 hours ago 0 replies      
thrownaway2424 8 hours ago 1 reply      
Counting global variables is just silly. I think any number of global variables is perfectly fine.
Silk Road successors economist.com
44 points by SimplyUseless  5 hours ago   18 comments top 3
cyphunk 2 hours ago 0 replies      
That one chart single handedly shows how permanent the idea of online drug markets are and also how attractive the field currently is for further innovation. It shows a market with high turn-over which to the minds of a geeky criminal translates to the question "can I do it better and survive longer?"

As a .gov I'd be concerned that the eventual party that does get it right, might have state support. A situation where instead of paying the bills of drug addiction therapists within the site, as Silkroad did, it would ban them outright.

hackercurious 4 hours ago 3 replies      
ROSS ULBRICHT has been sentenced to life in jail for his role in the Silk Road.

This article shows what a waste of resources this trail was. Online markets for illegal substances are going to follow the path of file sharing, both are nearly impossible to stop.

"Closing down the webs biggest drug shop has simply cleared the way for competitors."

sytelus 1 hour ago 2 replies      
Can you imagine what if someone open sources these kind of websites? Then pretty much every big shot drug dealer would have their own copy without needing much tech expertise. Silk Road got busted in part because DPR failed to fix bugs that caused IP leaks. But if it was open sources then these bugs would have been quickly fixed and busts would become increasingly challenging. I think DPR's vision is undeniable. Ultimately, the invention of Internet is leading to free choices that can no longer be suppressed by laws or even morality of situation - whether we like it or not. The ethical questions such as what if children uses these websites or what if your brother became heroin addict because of it - these questions would painfully be mute in face of technological reality that will be enforced upon us. In effect, we are slowly but steadily moving towards a framework that is dramatically going to be different than traditional governments, regulated economics, monopolized currencies, power hierarchy, bureaucracy, rather indirect democracy and laws crafted for vested interests as opposed to people themselves. There seems to be some purer form of laws that seems to be taking form all by itself that won't be human manufactured and probably would be as enforcing, universal and powerful as laws of nature itself - at least as long as we allow technology to exist.
Paris Geothermal Boom Brings Deep Drilling to Crowded Suburbs bloomberg.com
14 points by adventured  5 hours ago   2 comments top
cju 2 hours ago 1 reply      
I live nearby Bagneux, one of the cities mentioned in the article. People who are living near the drilling location are complaining a lot due to the noise and vibrations. It seems the drilling has to be performed continuously (24/7) so it's impossible to sleep or even live quietly. The company is paying hotel nights for many inhabitants.
Show HN: Woofmark: a modular, progressive Markdown and HTML editor github.com
51 points by bevacqua  11 hours ago   8 comments top 4
jchampem 4 hours ago 0 replies      
I like it. In fact I am considering using it for a project I am currently working on (https://github.com/jchampemont/notedown) as well as your other project 'insignia'.
logane 9 hours ago 2 replies      
Cool demo [0]. The highlights around the text editor and the ambiguity of the buttons' functions (what does a button labelled "." intuitively mean?) ruin parts of the demo for me though. Maybe consider using a different color / scheme for the active box highlighting + more standard buttons.

[0] http://bevacqua.github.io/woofmark/

bababoosh 6 hours ago 0 replies      
Cool, slightly OT, I currently use Voog Wysiwyg since some years, should I use woofmark instead? Any other wysiwyg editor? (Markdown stored is fine with me
unindented 6 hours ago 2 replies      
I found it interesting that the project's only dependencies are also written by the author: https://github.com/bevacqua/woofmark/blob/1ffb31db3008c3c018...

Is it a case of NIH, or is it justified?

Medical Devices: The Therac-25 (1995) mit.edu
63 points by pdkl95  12 hours ago   15 comments top 8
joezydeco 9 hours ago 0 replies      
Just another plug for the comp.risks digest. This digest from the ACM Committee on Computers and Public Policy has been moderated continuously by Peter G. Neumann since its inception in 1985. If you don't frequent Usenet like you used to in the 80s, the web archive is here:


The Therac-25 was discussed here many times, starting with Vol. 3 Issue 9:


phkahler 10 hours ago 1 reply      
I've always taken that machine as a argument against event driven programming. Why? Well John Carmack articulated the problems very nicely when he wrote about inline code, covered on HN here:


The Therac problem was a result of states getting out of sync and into an undesirable configuration. I think reading about the machine and then the above Carmack will cause one to see the connection.

bjoveski 11 hours ago 0 replies      
this might be a good guideline for the folks that don't want to read all of the paper.


The Leveson paper is quite long, and not all parts are equally important:

 Skim Sections 1 and 2. You should understand the basics of the Therac-25's design and how it was used. (You may also find this figure a helpful accompaniment to Figure 1 on page 4.) Skim Sections 3.1-3.3, which detail a few of the Therac-25 incidents. Read Sections 3.4 and 3.5. These detail a particular incident, the software bug that led to it, and the response to the bug. Pay close attention to 3.5.3, which describes the bug. Skip Section 3.6. (It describes an additional incident and a different bugfeel free to read if you are interested, though) Read Section 4 closely.

mcroydon 9 hours ago 0 replies      
Not to be self-serving, but I've always been fascinated by Therac-25. I ended up doing a deep dive a few months back and put together a short 5ish minute podcast episode about it:


I used this PDF as one of the primary resources and it was a fascinating read.

InclinedPlane 9 hours ago 2 replies      
Similar problems still exist, turns out software is hard: https://medium.com/backchannel/how-technology-led-a-hospital...
angersock 11 hours ago 1 reply      
While this is pretty much the Ur-example of faulty software design causing human injury, the fact is that the entire system failed. Had the Therac-25 not removed the hardware interlocks of the Therac-20, the accidents would've been much less likely to occur.

I also think that we should be careful in trying to draw too much caution in what we do from this accident--the majority of software (EHR systems, apps, etc.) being developed in the medical field today would not be served by the sort of scrutiny that would've prevented this accident.

In fact, one could (and I will) make the argument that simply having faster release cycles and better customer interfacing (instead of, say, custom consulting work coughEpiccough) would cause a better increase in quality than some insanely rigorous pile of paperwork.

theGimp 11 hours ago 1 reply      
Interesting read, but please label PDFs. I hate clicking on them while on my phone.
cheeze 10 hours ago 0 replies      
Please add a PDF warning.
Introducing Opener medium.com
16 points by timonus  8 hours ago   8 comments top 3
hobo_mark 4 hours ago 1 reply      
> Why dont links just open in apps?

I am not familiar with iOS but in Android they do, since day one, how is iOS different in that regard?

tilt 3 hours ago 0 replies      
How does it compare with http://applinks.org/?
ballpoint 3 hours ago 3 replies      
This looked awesome, but I found it on the app store and you're charging. I don't think this is a serious enough problem for me to pay you to fix it.
TIS-100 Tessellated Intelligence System zachtronics.com
87 points by holmak  16 hours ago   17 comments top 7
ShaneWilton 14 hours ago 3 replies      
Zachtronics Industries makes incredible engineering games. I haven't tried this one (though plan to tonight), but if this looks interesting to you, definitely check out some of his older work.

Ruckingenur II in particular is interesting. It places you in the role of a hardware reverse engineer, tasked with tinkering with circuits for anything ranging from basic electronic locks, to the copy protection on the Gamecube, with the goal of bypassing different security mechanisms. It's a really novel game.

You can play it for free here: http://www.zachtronics.com/ruckingenur-ii/

fpgaminer 12 hours ago 2 replies      
Looks cool, and I've enjoyed Zachtronics games before. I wish the demo video was longer and gave a better idea of the gameplay, though. I might throw the $7 at it anyway to find out.

I've had a vague desire for a game like this lately. I wasn't really around for the early computing era (my first computer was a 486), but I've played with the old machines and learned a lot of the history. There's a special kind of fun to be hand with them, and a sort of peace in working with their simplicity. They offer an oasis from the ever increasing complexity around us. Like the peace one gets from working on a garden; it's still work, but the work is simple, rewarding, and just for your own benefit.

My desire went so far as to build and tinker with my own game. It was to be like Elite, but you pilot your spaceship using only a Commodore 64 esque computer. You had to program everything for it. There were no flight controls or anything, instead you wrote programs to control the thrusters how you wanted, control weapons, drive the radar and plot the detected objects on the screen, etc. If you wanted keyboard controls of the thrusters, you made a program for that. And I had plans to add inter-ship modems so you could build scout ships with automated scouting programs that send back their data.

It was HTML5+JS based, and I got it to the point of having a working asm.js 6502 simulator, various peripheral hardware, MS BASIC, thrusters, radar, and a solar system to explore. But I got busy and had to stop. One major roadblock was that BASIC was terrible at all the register banging required to write most of the needed programs. So to make it "fun" I would have had to bring up a respectable DOS-like OS, a C compiler, and a code editor.

I really loved the idea though. It had all the fun, cool, retro elements of working on a C64, combined with the fantasy-lore of space adventures. My head swam with neat ideas like adding radiation dangers which could begin flipping RAM bits; interacting with space stations using your on-board modem so that all the Elite-like markets were operated like old BBS software; wormholes that gave you access to alien systems with powerful but undocumented peripherals; etc.

FrankenPC 11 hours ago 1 reply      
I remember when I first installed Omega for the PC. http://en.wikipedia.org/wiki/Omega_%28video_game%29I thought it was the greatest game ever made at the time. However, it was too easy to optimize and win. If I ever decided to create a game, I was definitely going to do something along the lines of a programmable battle simulator.This is a long winded way to say that I'm VERY glad to see Zachtronics making games which assume there is a market for gamers who enjoy programming. I hope to see more like this in the future. Side note: Just purchased this on Steam. Looking forward to cracking it open.
amelius 2 hours ago 0 replies      
This sounds more like work than a game.
karmicthreat 14 hours ago 0 replies      
I'm glad the time between Zachtronic games is shorter now.
blake8086 7 hours ago 1 reply      
Wow, Steam really made this painful. I bought the game, only to find out it doesn't run on my platform. No refunds! Beware, I guess.
tempodox 1 hour ago 0 replies      
Too bad it's Windoze only.
       cached 2 June 2015 13:02:02 GMT