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December 13

How to close current page in HTML/Javascript (on all platforms) ?

Note that the current page is not one that I opened with Javascript (let's say the user clicked on a link after a Google search to get here). I tried:

window.close();

This only seems to work on some platforms. I found many suggestions online, but none that work on all platforms I tested (Chrome, Firefox, Opera, and IE). Any ideas ?

Thanks, StuRat (talk) 02:54, 13 December 2015 (UTC)[reply]

MDN says you're only allowed to call window.close() on a window that was opened with window.open(). So you can't close arbitrary windows with JavaScript. (Thankfully. I don't want scripts closing my windows whenever they feel like it.) --71.119.131.184 (talk) 22:33, 13 December 2015 (UTC)[reply]

Javascript clue?

I have a quiz with 10 questions (each question should bring 10 points if answered correctly). Each question is a yes or no question. Whenever a user clicks on the right answer a string "Y" (Y) appears, and when ever it clicks on the wrong answer an "X" (X) appears.

My question is, if I want that every Y to bring +10 points, and every X to bring -10 points to the total possible sum of 100 hundred points, what is the right way to do that? How could I use each printed Y\X to add or subtract 10 points?

Thanks, Ben-Yeudith (talk) 16:22, 13 December 2015 (UTC)[reply]

You could concatenate them all into a 10 character string, then loop through the string, and examine each character, and add or subtract the points for each. However, it would seem to me that you already have an if-then statement for each Q that decides whether it was answered correctly or not, so you might as well just adjust the total inside that if-then, rather than do it later (initialize the total to 0 at the start of the quiz). Also note that the -10 for a wrong answer is typically done to dissuade quiz-takers from just guessing, and this implies that skipping a Q they don't know how to answer should also be an option. StuRat (talk) 22:11, 13 December 2015 (UTC)[reply]

I just slapped this together a couple weeks ago to help my class study for a final. View the source code to see if it helps. [1] 209.149.113.52 (talk) 14:37, 14 December 2015 (UTC)[reply]

December 14

What is the cost of pirated software for the users?

Is there any reliable and independent source analyzing hidden costs of pirated software? I mean direct costs for the users, not just nebulous costs like less proprietary software available, or less technical support. I am thinking aobut fines if being caught, malware, malfunctioning, time spent trying to find it and cracking. --3dcaddy (talk) 00:35, 14 December 2015 (UTC)[reply]

You do know this is a difficult question. The costs are different depending on your circumstances. If you earn $130,000 a year the cost of pirated software is difference than if you are unemployed and earn $0 a year. If you are unemployed, the cost of pirate software is acceptable even if you get malwares because you literally have nothing for the malware owner to steal off you! 175.45.116.66 (talk) 04:58, 14 December 2015 (UTC)[reply]

The malware can steal your computer from you. Imagine that 99% of your computer's processor and 99% of your network bandwidth is used by malware to send out spam. You have effectively had your computer stolen. Now, you have no money (as you claim) and, if you are in this situation, no knowledge of how to remove the malware. So, you have two options: turn the computer off and never use it or turn it on and never be able to use it. 209.149.113.52 (talk) 20:28, 14 December 2015 (UTC)[reply]

I don't know how independent the study has to be. But Microsoft sponsored a study, which was conducted independently, about the economical impact of software piracy. It was conducted by IDC and the National University of Singapore (NUS) and can be downloaded from [2]. --Denidi (talk) 13:54, 14 December 2015 (UTC)[reply]

In the 1980s a pirtated software was detected by its updates and demo versions. Those offered a free user manual when a software version with dongle crack was detected. The coupon code clarified what illegal copy was installed on the computer. The promised «user manual» was sent by an attorney to these computer users and made them pay for the software and the losts of the software vendor. Today, every computer in use is connected to the internet and software is used to call home. --Hans Haase (有问题吗) 00:07, 15 December 2015 (UTC)[reply]

Are you using Google Translate for your posts Hans? I have difficulties understanding most of it. And I don't se how the bits that I understand relate to my answer. --Denidi (talk) 02:58, 15 December 2015 (UTC)[reply]

Yes, I did. The post is updated now. --Hans Haase (有问题吗) 23:55, 17 December 2015 (UTC)[reply]

Image help

This image appears to be divided into multiple portions and Dezoomify doesn't help. As I'm quite lame in it, could someone help in possible stitching and downloading in maximum resolution over File:H. Piffard - The Thin Red Line.jpg? The image is in public domain, as the artist Harold H. Piffard died 77 years ago. Brandmeister^talk 16:10, 14 December 2015 (UTC)[reply]

I uploaded a full-resolution version. (I used Chrome's network inspector to see what images the page was requesting from the server. The tiles have URLs like ...&DMSCALE=15&DMWIDTH=512&DMHEIGHT=512&DMX=...&DMY=...&..., and by replacing that with DMSCALE=100&DMWIDTH=8192&DMHEIGHT=8192&DMX=0&DMY=0, I was able to download the whole image as one "tile".) -- BenRG (talk) 19:10, 14 December 2015 (UTC)[reply]

The full-resolution image has a bunch of dots all over it - it looks like it was a very high resolution scan of a very low resolution printed image from a book or a magazine or something. Grabbing the highest resolution version is not particularly useful.

SteveBaker (talk) 00:40, 16 December 2015 (UTC)[reply]

Yes, the color rosettes are visible. It has far more real detail than Brandmeister's upload, even when downscaled to the same size ([3] [4]). It could probably be downscaled somewhat without losing "important" detail, but the savings in storage and processing costs would probably amount to less than 1¢ over the lifetime of Commons. It's not worth thinking about even at minimum wage. -- BenRG (talk) 22:01, 17 December 2015 (UTC)[reply]

Freegate not working

Hi all, I've been using Freegate as a proxy in China, and it has worked fine in the past, but lately it has started playing up rather badly. It won't find any servers, and when it does, it usually cuts out quickly. Then, last night, it started working, eventually. Then I disconnected the internet, and today, it is up to its usual tricks. It usually just says "No server is available. Please try again later." Has something changed with Freegate, has the Chinese government worked out how to defeat it, or am I having an unlucky run? IBE (talk) 17:10, 14 December 2015 (UTC)[reply]

Writing smartphone applications in various languages

Hello,

Will it be possible in the foreseeable future to write a program in any of the major programming language (Python, Javascript, C++ etc.) that would run on different smartphone operating systems such as Android, iOS, etc? Thanks, 109.160.175.221 (talk) 19:02, 14 December 2015 (UTC)[reply]

There are a number of frameworks like Xamarin which allow cross-platform development, and many more which wrap HTML/CSS/JS into applications which can run on a range of smartphone platforms - see Multiple phone web-based application framework. -- Finlay McWalterᚠTalk 19:14, 14 December 2015 (UTC)[reply]

December 15

Windows cannot install important updates

Information as of 2009: OS Name Microsoft® Windows Vista™ Home Premium Version 6.0.6001 Service Pack 1 Build 6001 Other OS Description Not Available OS Manufacturer Microsoft Corporation System Name System Manufacturer HP-Pavilion System Model KT369AA-ABA a6512p System Type x64-based PC Processor Intel(R) Pentium(R) Dual CPU E2200 @ 2.20GHz, 2200 Mhz, 2 Core(s), 2 Logical Processor(s) BIOS Version/Date American Megatrends Inc. 5.23, 4/21/2008 SMBIOS Version 2.5 Windows Directory C:\Windows System Directory C:\Windows\system32 Boot Device \Device\HarddiskVolume1 Locale United States Hardware Abstraction Layer Version = "6.0.6001.18000" User Name Time Zone Eastern Standard Time Installed Physical Memory (RAM) 4.00 GB Total Physical Memory 3.99 GB Available Physical Memory 2.15 GB Total Virtual Memory 8.18 GB Available Virtual Memory 6.13 GB Page File Space 4.28 GB Page File C:\pagefile.sys And on 7 August 2009 I was told to always say I HAVE A DSL MODEM.

Last week my computer would not start and I got a message saying I could tell the computer to repair itself. It went through system restore and everything seemed fine. During the time right after the computer is turned on, I have been getting numerous messages, on a blue screen, that the computer had to shut down to protect itself. And that happened again yesterday. I had to restart the computer because of Windows updates, which had also happened prior to the system restore. I waited until I was ready to turn off the computer after the updates finished installation because I didn't want to have to figure out how to get back to what I was working on. But today, the monitor went black and said "no signal", and the computer started beeping. This has happened a couple of times, mostly right after the computer was turned on, but also once when I did the virus scan and left it alone and it was "asleep" after that finished. So I unplugged the computer and when I turned it back on, I was told I should probably do a system restore. Which I did. Everything seemed to work after that, but surprise! The logo in the lower right corner is there again, and when I move my mouse over it, it says "Windows is downloading updates (46% complete)". Earlier, I got a little popup message saying Windows could not install important updates, and to click to find out more. It went away before I could click and I don't know where to click. But obviously I need to stop Windows from installing any more updates until this problem is fixed.— Vchimpanzee • talk • contributions • 20:34, 14 December 2015 (UTC)[reply]

Sorry to say you're having so many issues with your computer.. This is a computer reference desk, it's not really "troubleshoot" your windows issues, I'm sure people will be happy to give you some tips but do you have an actual question? is it just "how to disable automatic updates?" That should be fairly simple, this is the 1st result of a google search. Vespine (talk) 21:39, 14 December 2015 (UTC)[reply]

I'm not sure what my actual question should be. I'm up to 61 percent now and will be turning off the computer soon unless I remember that I want the download to be completed. Though I probably don't. But I'm trying to figure out what could be causing all these problems. I don't really get specific enough error messages when these problems happen. McAfee also downloaded updates and I don't know whether these could be causing the problems. But if they did, that's harder to deal with since I know I need McAfee to be up to date. They have tech support though I don't have time for that today, and if the problem is serious enough they might charge me extra. How to explain all this to them I don't know.— Vchimpanzee • talk • contributions • 22:11, 14 December 2015 (UTC)[reply]

From the symptoms you describe, there's a fair chance a hardware fault is the cause although I'd try and rule out overheating by cleaning any fans first. Nil Einne (talk) 22:28, 14 December 2015 (UTC)[reply]

Thanks, but I'm not sure cleaning a fan is something I can do. The computer doesn't feel hot and I don't feel heat around the vent. Going inside is not something I feel confident about. I'll ask McAfee for help Wednesday and see if there's anything related to their software that can be fixed.— Vchimpanzee • talk • contributions • 23:32, 14 December 2015 (UTC)[reply]

Cleaning fans is something a child can do. Get a can of gas duster (often referred to as "canned air" though this is not actually correct), which you can find all over the place, remove the side panel, and blow dust out. You don't even have to touch anything inside. You'll probably want to do this outside. This is something you should do periodically, since computers accumulate dust over time, which makes them hotter, which is bad for the hardware. If you want to watch someone doing it first there are fifty billion videos online. --71.119.131.184 (talk) 05:43, 17 December 2015 (UTC)[reply]

A corrupted update downloads or update database can be fixed by clearing the folders catroot and catroot2, located in Windir or System32. Usually, these services are running and access the files. Stop all services to see the ms knowledgebase to find which services needs to be stopped to release the files in the catroots and allow to delete the files in the folders. When done, restart as the best way to restart all the services. The catroot files wil be rebuild automatically. It will take longer to check for updates the next time, but do not interrupt it. --Hans Haase (有问题吗) 00:00, 15 December 2015 (UTC)[reply]

"The monitor went black and said 'no signal', and the computer started beeping" strongly suggests a hardware problem, possibly with the video card. I doubt that Windows Update is causing the problem, or that disabling it will help, though I suppose it's worth a try. -- BenRG (talk) 00:53, 15 December 2015 (UTC)[reply]

Update: Windows successfully installed updates. I forgot and turned off the computer when downloading was not complete. It resumed at 72 percent and is up to 76. I had a McAfee support person preparing to look at my computer in case anything from them caused any problem. The connection was lost 20 minutes ago and I am trying to resume.

And today, I went to McAfee first rather than my email. There were no problems but I can't say why.— Vchimpanzee • talk • contributions • 19:27, 16 December 2015 (UTC)[reply]

The person from McAfee said to call. I did. We just finished up and the other person found no obvious problems. Part of that was turning on the computer. Still no problems. Windows is at 99 percent.— Vchimpanzee • talk • contributions • 22:40, 16 December 2015 (UTC)[reply]

Windows can take an unreasonably long time if it is doing lots of updates over a slow modem. If it finishes, you will probably be OK (at least we hope so). Dbfirs 19:21, 17 December 2015 (UTC)[reply]

Devices in and out

You know when you put in a device like a cam or such and Windows XP goes "blong bling" and when you take it out, the computer goes "bling blong"? Sometimes when I take it out, it doesn't go "bling blong" for a long time or not at all. Is there anything I can do? Many thanks. :) Anna Frodesiak (talk) 01:34, 15 December 2015 (UTC)[reply]

It is a very low priority process. It isn't necessary, so it tries to play the little tune, but the system is perfectly happy to skip it if the CPU or sound processor is too busy. Why is the CPU busy? If you are running XP, the probability that you have malware on your computer that is using up all your CPU cycles is very very very high. 209.149.113.52 (talk) 13:16, 15 December 2015 (UTC)[reply]

I understand. But it is more than just the tune. If I reinsert the device, it is not recognized unless that tune happens. Also, I don't think my cycles are being used up. My computer is very fast, my task managers's CPU usage history shows it stays at near 0% all the time. Anna Frodesiak (talk) 23:29, 15 December 2015 (UTC)[reply]

Problem in running a OBB file

I have an OBB file in my pc, but I don't know the exact software to run it. Please, suggest me a software through which I can extract the contents of my file. — Preceding unsigned comment added by 223.176.38.113 (talk) 05:38, 15 December 2015 (UTC)[reply]

We have an article on Opaque binary blob, but you might need an Android emulator to run it on your PC. Do you just want to inspect the file? Dbfirs 10:52, 15 December 2015 (UTC)[reply]

I want to run this file without using android emulators. I want to extract its contents and hence, install the program using the extracted setup file.182.66.101.114 (talk) 06:18, 16 December 2015 (UTC)[reply]

You must have a clever PC if it can run Android code without an emulator. It should in theory be possible to extract the data files from the OBB, but I don't know how to do that. The creators of OBBs tend to obscure the structure. Dbfirs 08:39, 16 December 2015 (UTC)[reply]

A lot of Android programs are shipped as Dalvik/ART bytecode, so it depends on what you mean by "emulator", which is an ill-defined term. Certainly if you want to run the software unmodified you need to provide the Android platform's bells and whistles, but you don't need to emulate a processor architecture. Although there are native-code Android executables, so you can't guarantee that for any arbitrary Android software. Wine is a better-known example of this fuzziness; it doesn't do any CPU emulation. For that matter, "PC" is similarly ill-defined. There are Android netbooks and the like. People don't always mean Wintel when they say "PC" (especially if they aren't computer nerds like us). --71.119.131.184 (talk) 05:36, 17 December 2015 (UTC)[reply]

Well, in my experience, "PC" is synonymous with "Wintel" these days, even though a "personal computer" originally meant any computer used by an individual instead of an organisation, and even IBM PC -based computers can run a variety of OSes. There are even IT professionals who market their software as "PC, Mac, Linux" as if Linux was a separate physical computer and not just an operating system for PCs (and possibly other computers too). JIP | Talk 20:38, 17 December 2015 (UTC)[reply]

Well Wine would provide compatibility the other way round, unless our article is out of date. I admit I hadn't taken into account that the OP might have meant a Tablet computer. Dbfirs 19:07, 17 December 2015 (UTC)[reply]

@Dbfirs: I took the liberty of fixing your wikilink. Wine goes to the actual alcoholic beverage, you want Wine (software). JIP | Talk 20:35, 17 December 2015 (UTC)[reply]

Oops! Thanks for that. I hadn't been drinking it, honest ossifer! Dbfirs 20:53, 17 December 2015 (UTC)[reply]

Video upscaling question

When displaying a video (or image) whose resolution is lower than that of the display panel, the video is upscaled.

Assume that I have 2 monitors of the same physical size but difference resolutions: 720p and 2160p. Is there any difference when they display a 720p video? I think the 2160p monitor just use 3x3 pixel block to simulate a 1x1 block of the 720p video, and there is no pixel stretching at all. 14.177.58.42 (talk) 20:30, 15 December 2015 (UTC)[reply]

There won't be stretching but you might notice the lesser quality of the 720p video. After all, there's less pixels and therefore less detail in the 720p video frames, which are now being displayed at 2160p. FrameDrag (talk) 21:37, 15 December 2015 (UTC)[reply]

There are many, many ways of upscaling...and the visual results are different in each case.

Pixel replication - so if your monitor is 2x higher resolution than the image, then you'll have 2x2 areas of completely uniform color. This can result in visible aliassing.
BiLinear interpolation - the system blends the colors of adjacent image pixels to fill in the gaps between them...so on a 2x resolution screen, a hard black/white edge in the original image looks like a soft blend through mid-grey. This can result in the image looking blurry.
Cubic/Quartic interpolation - similar to the above except the blending of adjacent colors is done gradually, then steeply, then gradually again. Looks better than bilinear - but is more expensive for the electronics to calculate.
Lanczos resampling - a yet more complicated way to do this that results in yet better images.

Then those things may be done in linear color space or gamma-space...much other things may be involved.

The results are therefore extremely dependent on the algorithm being used. On a moving picture, the results can be even more involved. If the video image is compressed then the motion compensation can be done pixel-perfect at the higher resolution, resulting in smoother motion on the higher resolution device.

Bottom line...it's not that simple!

SteveBaker (talk) 00:35, 16 December 2015 (UTC)[reply]

Noting that you have a nice integer ratio, that makes for the best upscaling. On the other hand, say when upscaling from 720 to 1080, then some pixels are duplicated while others aren't, resulting in distortions. Either that or the software does some type of interpolation to turn 2 pixels into 3, which still won't look all that good. I wish there was always an option to just keep it at the lower resolution, and use only a portion of the screen, but I've rarely seen that option. StuRat (talk) 06:57, 16 December 2015 (UTC)[reply]

It's not particularly hard on pretty much any computer, or most smart TVs. Nil Einne (talk) 13:22, 16 December 2015 (UTC)[reply]

If you mean displaying at a lower than native res on a computer monitor by only using that portion of the screen, so you still have 1 pixel to 1 pixel mapping, I don't believe I've ever seen that option on a computer monitor. Instead, they automatically upscale to use the full screen. StuRat (talk) 17:09, 17 December 2015 (UTC)[reply]

In addition to SteveBaker's comment, see image scaling. madVR is a popular video renderer on Windows for people interested in high quality video upscaling. It's GPU assisted and supports quite a few different upscaling and downscaling algorithms. This includes increasing the resolution by 2x, 4x or 8x as necessary and then downscaling or upscaling as needed. super-xbr and NNEDI3 are popular but demanding scaling methods. (Modern GPU generally have their own algorithms, but madVR is normally considered to offer better quality if your hardware can support it.)

I don't think the claim "A 720p video on a 720p screen always looks better than the same video on a 1080p screen due to pixel stretching" is universally true. I'm fairly sure there are people who prefer the look of a 720P video (or whatever) upscaled with a quality upscaler on a 1080 display, than on a 720 display (i.e. displayed natively) even everything else being equal (which is almost impossible with displays anyway). Once you get to significantly higher resolutions like 2160 (or even a non integer like 2520) it will get even more likely.

An existing common example would be that many people would prefer the look of a SD video upscaled with a quality upscaler played on a 1080 display even if that SD video resolution was non integer (as they often are) to 1920x1080 (or whatever resolution needed for the aspect ratio); than they would that same video non upscaled. Although we are talking far lower resolutions here, and finding a display equivalent in every other way but the resolution would be very difficult. (Probably the best you can do is to use a projector and different lens or distance to achieve the same size while using different numbers of pixels, but that still wouldn't be perfectly equivalent.)

Of course, as was discussed very recently, many people also fool themselves in to thinking they notice some difference when they actually don't (and given the distance, size and how well they see, perhaps can't), so that also needs to be taken in to account in any test. In particular, I suspect the most common thing would be that people won't actually notice the difference between any of these: 720P content played natively on a 720 display, 720P content played upscaled with a fancy algorithm on a 1080 display and 720P content played upscaled with a resonably simple (well better than nearest neighbour) on a 1080 display; if everything else is equal.

Still the takeaway message remains sound, it's foolish to assume everyone prefers something, just because someone (perhaps you) does.

Nil Einne (talk) 13:44, 16 December 2015 (UTC)[reply]

It really depends on the content you are upscaling. For things typically displayed on a computer monitor, like text and lines, you really want to avoid non-integer scaling. For example, if every other line of pixels alternates between black and white on a 720 image, and you upscale that to 1080, it's going to look horrid. But for typical TV images, like moving pics of people, I don't think it much matters if you view native 720 or 720 upscaled to 1080. StuRat (talk) 17:15, 17 December 2015 (UTC)[reply]

The tough thing is text - particularly text that's overlaid on live action video. As you say, for live action video, simple pixel replication works reasonably well - but for text you need some kind of interpolation. But interpolation can make other kinds of image blurry. If you're watching some sporting event and you have overlaid stats and logos and such - you have every kind of image all on the screen at once. What's optimal for one is pessimal for the other. My TV has modes for viewing different kinds of content - and probably that setting changes those kinds of decisions - but most people are not willing to dive into the menus to change the settings every time they flip channels or watch a different show. So the TV inevitably winds up in some compromise mode that's optimal for the "In-Store-Demo" and never changes from that. SteveBaker (talk) 16:47, 18 December 2015 (UTC)[reply]

December 16

Representation of numbers in binary

I would like to know why we can't represent binary numbers in power of two?

For example 5381 can be represented as 5 × 10^3 + 3 × 10^2 + 8 × 10^1 + 1 × 10^0 = 5381 while 1101 can't be represented as power of two's. We can't write 1101 as 1 × 2^3 + 1 × 2^2 + 0 × 2^1 + 1 × 2^0 even though this gives the decimal equivalent of 1101 i.e 13. Is there any way to represent 1101 in power of two's but after adding the terms in the represented form we should again get 1101?JUSTIN JOHNS (talk) 09:08, 16 December 2015 (UTC)[reply]

That is because you are adding in decimal instead of binary. Bubba73 ^{You talkin' to me?} 06:12, 17 December 2015 (UTC)[reply]

Um, 1101 in binary is equivalent to 1 × 2^3 + 1 × 2^2 + 0 × 2^1 + 1 × 2^0. Why did you think it wasn't representable that way? --76.69.45.64 (talk) 09:57, 16 December 2015 (UTC)[reply]

1101 in base 10 (i.e. 10^3 + 10^2 + 10^0) is 10001001101 (=2^10 + 2^6 + 2^3 + 2^2 + 2^0) in binary - does that help? AndrewWTaylor (talk) 12:09, 16 December 2015 (UTC)[reply]

Is your concern that writing

1101₂ = 1 × 2³ + 1 × 2² + 0 × 2¹ + 1 × 2⁰

uses the digits 2 and 3 which not binary? That is because the right hand side is in base ten notation, not binary. If you want it all in binary, you can write

1101₂ = 1₂ × 10₂^11₂ + 1₂ × 10₂^10₂ + 0₂ × 10₂^1₂ + 1₂ × 10₂^0₂

-- ToE 12:45, 16 December 2015 (UTC)[reply]

On second reading I'm still not sure of the questioner's concern, but I now suspect that AndrewWTaylor answer that 1101₁₀ = 10001001101₂ is more likely to address it. -- ToE 13:48, 16 December 2015 (UTC)[reply]

I'm not quite sure what Justin's concerned about, either, but another thing that's important to remember is that when we talk about "base 10" and "base 2" and the like, we're only talking about numeric representations of numbers; we're not changing the underlying number. If I ask you to count the number of x's here:

xxxxxxxxxx

you will say "ten", and if I ask you whether your answer was in base 10 or base 2, you'll look at me funny and say "Huh?", because changing the base does not change the number of x's on the line, it's still ten.

But it's easy to get confused, because when we see "10" we automatically pronounce it "ten", not "one zero". Strictly speaking, "ten" is "10₁₀", and we ought to pronounce "10₂" as "one zero base two", not "ten base two". (Or maybe I'm splitting hairs. But remember, "There are 10 kinds of people in the world, people who understand binary numbers and people who don't.") —Steve Summit (talk) 15:04, 16 December 2015 (UTC) [edited 15:46, 16 December 2015 (UTC)][reply]

I am tired of this joke about 10 kinds of people. Don't remember how many times I heard it. Although the first time I heard it in CS 101, my fifth course, I found it funny. --Denidi (talk) 18:33, 16 December 2015 (UTC)[reply]

Speaking of old jokes: you learned about binary in CS 101? --76.69.45.64 (talk) 03:43, 17 December 2015 (UTC)[reply]

Sorry Dendi. Anyway, the joke is incorrect. There are really 10 kinds of people, those who understand ternary, those who heard the joke about binary and are now hopelessly confused and those who don't understand what the heck we're talking about. SteveBaker (talk) 04:04, 17 December 2015 (UTC)[reply]

Enough with the stupid old nerd jokes. Happy upcoming OCT 31, everybody. —Steve Summit (talk) 04:31, 17 December 2015 (UTC)[reply]

I once took a Unix sysadmin class whose teacher was missing two fingers. When we got to chmod, I thought of Tom Lehrer. —Tamfang (talk) 05:10, 17 December 2015 (UTC)[reply]

Eventhough 1101₂ = 1₂ × 10₂^11₂ + 1₂ × 10₂^10₂ + 0₂ × 10₂^1₂ + 1₂ × 10₂^0₂ is the correct way to represent the number in binary it doesn't gives us the value 1101 rather it gives the value 13 which is the decimal equivalent of 1101.I think it may not be possible to produce such a representation eventhough in decimal it's possible.This might be a weakness of binary but not sure about it.JUSTIN JOHNS (talk) 06:46, 17 December 2015 (UTC)[reply]

The thing is, the value 1101 in binary is exactly the same as the value 13 in decimal. It's sort of like if I asked you how far it is to the end of the road - 300 feet, 100 yards, 91.44 metres, and 9.66E-15 light years are all the same answer, just in different units. 1101₂ and 13₁₀ are the same number, just in a different base. MChesterMC (talk) 09:40, 17 December 2015 (UTC)[reply]

Somewhere I have a marvelous old HP "programmer's calculator" that does decimal, binary, octal, and hex. If I put it in binary mode and ran the calculation 1₂ × 10₂^11₂ + 1₂ × 10₂^10₂ + 0₂ × 10₂^1₂ + 1₂ × 10₂^0₂ (rearranged into RPN, natch), the display would show 1101. —Steve Summit (talk) 11:15, 17 December 2015 (UTC)[reply]

I think User:scs's comment is correct about this. Numbers aren't in any base, they just are numbers. But in order to write them, we need representations of numbers, and those representations are in bases. The number of fingers on a person's hands can be written as 10₁₀ or 1010₂, but the actual number is still the same. JIP | Talk 18:47, 17 December 2015 (UTC)[reply]

Google Chrome on iOS

Hi, my Chrome app is acting weird. Specifically, when I look at these ref desk pages, they all come up with the last posts on December 12. They used to work fine, and all other pages seem to work fine. I've tried clearing my cache (and cookies, history, etc) in Chrome and also forcing WP to purge its cache, but neither helps. Any ideas? Thanks, SemanticMantis (talk) 15:11, 16 December 2015 (UTC)[reply]

Could an anti-virus and similar malware tools lead to less security?

In the same way that a seatbelt, air-bag or insurance could make people possibly drive less carefully, could an anti-virus make people be less careful with what they are doing? Risk compensation examples are rarely about computer security, but why wouldn't the phenomenon arise in this field? --Denidi (talk) 16:20, 16 December 2015 (UTC)[reply]

Sure, conceivably - as you ask, why not? Risk compensation seems to be pretty basic to how humans work. I can't find anything as explicitly empirical and data-driven as e.g. the Munich taxi data, but here's a journal article in Computers and Security that talks a bit about risk compensation in context of computer security [5]. SemanticMantis (talk) 16:35, 16 December 2015 (UTC)[reply]

When I am using someone's Windows PC I am super careful not to visit dodgy sites or to download and run anything. When I am at home running Slackware on a system that I can easily restore to last night's backup, I am less careful. When I am running Tails, or Tiny Core, both of which which lose all changes when I reboot (and I have not entered and will not enter any personal info or passwords during that session), I freely download and run anything that seems interesting. You could say that this means that my using Tails "leads to less security", but the simple fact is that when running Tails no malware can harm me, and I behave appropriately. --Guy Macon (talk) 21:07, 16 December 2015 (UTC)[reply]

I was going to drown you in a load of scholarly articles, but you can easily go to scholar.google.com and search for "mac users are less secure" and find more than you want to know about. To summarize, a quote from my brother, "I don't have to worry about viruses or hackers because I only use a Mac and an iPhone." 47.49.128.58 (talk) 15:25, 17 December 2015 (UTC)[reply]

As we discussed in February and March of this year - exactly what type of threat are you trying to secure your system against?

If your threat model is unrealistic, or incomplete, your security response will be equally unrealistic or incomplete.

I really find the thought-experiment about "hacking a vending machine" to be very instructive. If you fixate on cyber-security to the exclusion of physical security, you're probably overlooking the most obvious and important set of threats.

Nimur (talk) 17:14, 17 December 2015 (UTC)[reply]

Most computer users are taught that it is somehow their job to decide whether attachments and other links are safe to click on or not. If, instead, computers were programmed to simply categorize media into "safe" (words or images to display) versus "unsafe" (programs or other active content to execute), and only implement one-click openability on the former, users could click on links with abandon, but they'd actually be more safe, not less. (In other words, while it's certainly true that the provision of a safety system can cause people to worry less about security, this is not necessarily a bad thing, in fact it's arguably the whole point of safety systems. It is therefore not necessarily a reason to not deploy safety systems!) (But yes, returning to my earlier point, and before 1,267 people jump down my throat to lecture me, I do realize that some media, such as Flash and even Microsoft Word documentation, is not always so easy to discriminate across my "safe" versus "unsafe" dichotomy.) —Steve Summit (talk) 18:19, 17 December 2015 (UTC)[reply]

Yes, I'm going to jump down your throat for this. The difference between good guys and bad guys is not mathematically formalizable, so computers can't check for it. The distinction between "executable" and "nonexecutable" data is irrelevant. In-browser Javascript is Turing-complete but sandboxed, so theoretically as safe as "nonexecutable" text and images. In practice both are unsafe because of bugs in the implementations. Javascript may be more unsafe because of greater complexity, but there's no clear line. And phishing in its most basic form requires no exploitable bugs or executable code.

OSes could do much more than they do to protect people. Every program I run should not have read access to all of my personal files, much less write access. But some should, and I have to decide which ones. We know from smartphones and general UI experience that if you ask for permission to break a security barrier, many people will click "allow" without even reading the message. Those people need to be less stupid. -- BenRG (talk) 19:38, 17 December 2015 (UTC)[reply]

Not going to get into a long argument here, but we know from general experience that people are this stupid. If you believe that additional restrictions can't/shouldn't be built into computer systems, if you believe that the only solution is to keep trying to educate the poor users not to do "stupid" things, then the computer security problem is going to continue to get worse and worse -- and it's already unimaginably bad. (I'm not saying that you, Ben, believe these things, but plenty of people seem to.) —Steve Summit (talk) 20:02, 17 December 2015 (UTC)[reply]

For me, the most astonishing misunderstanding is the completely incorrect assertion that malware must have user-visible symptoms. Some malware will flood your UI with pop-ups... but such an infestation is easy to identify, and therefore an appropriate response can be taken. But there is a much more sinister threat. Great malware exists that never shows the user an annoying pop-up advertisement; never slows down the CPU or network in a meaningful way; never even appears in the technical data dumps, system logs, or power-user interfaces. These are the silent keyloggers and traffic sniffers and rootkits and illicit backdoors. A great piece of malware is one that you never even know is installed - it will just persist forever and the user won't even think about trying to clean it up. These invisible artful engineering marvels are only really appreciated by systems-programmers. This is the stuff that keeps me up at night - now that my AC power adapter has firmware - and a digital communication channel to the operating system - is that firmware exploitable? Can a thus-exploited AC-adapter-microcontroller get on to the main computer's system bus and sniff other traffic? How would I even know, unless I had the ability to deeply inspect the electronics schematics and the software implementations? Nimur (talk) 20:22, 17 December 2015 (UTC)[reply]

Once a month Windows Update downloads and runs a new version of Microsoft's Malicious Software Removal Tool. It's tailored to malware that's actually present in the wild, so by construction that malware can't evade detection by it. The malware could block Windows Update, but that's noticeable. -- BenRG (talk) 21:06, 17 December 2015 (UTC)[reply]

You can give people control of their own computers or not. If you do, some of them are going to break security barriers willy nilly. If you don't, because some software legitimately needs to break those barriers, a central authority has to decide which software gets that permission. This applies to every computer user, not just the irresponsible ones, unless the central authority also decides which users are responsible. The alternative is to give people control of their lives and try to educate them to not mess up their lives. Do you disagree with that? -- BenRG (talk) 20:56, 17 December 2015 (UTC)[reply]

You didn't get into the human side of it. The human user will not care about "safe" and "unsafe". If the link says something like "Click here to see Obama getting a blowjob from Hillary!" then it wouldn't matter how unsafe the computer labeled the link. The human would click it. Even if clicking it caused it to say "Hey Idiot! This is completely unsafe! Don't click it again you complete moron!", the human would click again and again and again. In the end, humans are the primary threat, not unsafe links or attachments. 47.49.128.58 (talk) 19:51, 17 December 2015 (UTC)[reply]

Not going to get into a long argument here, but when I said "only implement one-click openability on the former", I didn't say what I'd like to see done with the latter. (Hint: it is not "protect them with an 'are you sure?' prompt".) —Steve Summit (talk) 20:02, 17 December 2015 (UTC)[reply]

To answer the question in the subject line (if not the following paragraph), antivirus software is very complicated (modern scanners have built-in emulators for x86 and various bytecode languages, for example), it has access to all of your files and all of your data on all web sites (so it can scan them) and to the OS kernel, and it's not written by the world's smartest people. That means it opens an enormous attack surface when it's installed. This paper describes some exploits for Sophos antivirus that could be triggered without any user action (because Sophos scans things before you even get the option to open them) and led to full system takeover. Those bugs have been fixed, but the situation is probably the same now for every antivirus product because they are still very complicated and under active development. -- BenRG (talk) 19:38, 17 December 2015 (UTC)[reply]

"it's not written by the world's smartest people" Why would AV developers be below average? I don't associate them with low IQs.Denidi (talk) 22:29, 17 December 2015 (UTC)[reply]

Most (or all?) complex software has flaws. Even those with high IQs are seldom able to ensure that every possible attack route has been blocked. It's a race between AV software developers and malware writers, and sometimes the bad guys win. Dbfirs 08:57, 18 December 2015 (UTC)[reply]

But would competent hackers tend to the other side ? There are certainly good paid honest jobs in the security industry, developing AVs and all. --Denidi (talk) 15:08, 18 December 2015 (UTC)[reply]

December 17

PayPal problem

In PayPal, after I had mistyped the amount of deposit needed to confirm my bank account to remove limit on withdrawals, my linked bank account suddenly disappeared. When I try to re-attach my bank account, I repeatedly receive "Sorry, we are not able to process your request. Please try again later" after I fill the "Link bank account" form. I've already emailed PayPal, but received an unhelpful automated reply. Any ideas how to fix that? Thanks. 93.174.25.12 (talk) 12:08, 17 December 2015 (UTC)[reply]

I don't want a to alarm you unnecessarily, but the first thing that I would do is to run a good anti-virus and anti-malware scanner on the computer where the problem occurred. Alternatively, see if you can carry through the process on another computer. I'm not too familiar with PayPal so perhaps someone else here has other suggestions? Dbfirs 18:47, 17 December 2015 (UTC)[reply]

Maybe PayPal anti-fraud algorithm concluded that someone was testing the system. Somehow they have to exclude people who cannot verify their bank account. --Scicurious (talk) 19:07, 17 December 2015 (UTC)[reply]

Yes, perhaps they've locked the account, but shouldn't they have sent an e-mail to inform the OP of this? Dbfirs 08:48, 18 December 2015 (UTC)[reply]

Reading e-books on Linux

I recently bought an e-book about ASP.NET MVC to read at home so I could learn how it differs from ASP.NET Web Forms. It turned out that the download link didn't give me the actual e-book but instead a proprietary urllink.acsm file that Adobe Digital Editions could use to download the actual e-book. Well, Adobe Digital Editions isn't available for Linux. I had to install Wine and use Winetricks to download and install Adobe Digital Editions 1.7. This version must be hopelessly obsolete by modern standards but none of the newer versions would even start up under Wine.

Adobe Digital Editions 1.7 started up nicely under Wine, and I dragged and dropped the urllink.acsm file to its window. It downloaded the actual e-book, which I could read at my leisure.

Can I somehow read this e-book without Adobe Digital Editions, for example under Calibre, a native Linux e-book reader? I didn't find an EPUB file that the e-book would be stored in (as the webstore claimed), but I found a password-protected PDF several megabytes in size. Is this the e-book? Evince couldn't open it without the correct password, which I don't even know. Is there a way to get rid of this DRM nonsense so I could read the e-book freely?

I am of course not going to redistribute this e-book, that would be software piracy. This is only so that I could freely use the content I bought fully legally and paid good money for, for my own use. JIP | Talk 18:41, 17 December 2015 (UTC)[reply]

Use Windows.--Scicurious (talk) 19:06, 17 December 2015 (UTC)[reply]

I suggest you give feedback to the book publisher, and to the website you purchased the book from, saying that you find the limitations on reading the book a problem, and if these conditions were not made clear up front, you may be able to ask for a refund.-gadfium 21:09, 17 December 2015 (UTC)[reply]

What publishing house is this, if I might ask? I know DRMs just from library books. I even got the impression that publishers had abandoned completely the idea, since lots of users (also Windows based) have problems with it.--Denidi (talk) 22:57, 17 December 2015 (UTC)[reply]

The e-book was published by Wrox, and the distributor I downloaded it from was a Finnish e-book store called AdLibris. JIP | Talk 15:24, 18 December 2015 (UTC)[reply]

A couple of thoughts, in no particular order. Your friend when it comes to DRM is apprentice alf, whose tools can deal with the "Adobe Adept, Barnes & Noble, Amazon and eReader DRM schemes". Otherwise you're probably stuffed. If at all possible, I'd follow gadfium's policy, then give this store a very wide berth in future. On the other hand (while I'm not at all defending the bone-headed store and/or publisher), it seems that all you are intended to be able to do with this document is read it on a computer, rather than transferring it to an ereader, or whatever else you might want to do with it. You can read it on your computer, so you have all they intended to give you; the question then is whether you were led to believe that you would get more. Henry ^Flower 17:02, 18 December 2015 (UTC)[reply]

Errors: Relative, mixed or absolute cell reference in spreadsheets

What leads to more errors: referring to cells with an absolute location ($B$3), mixed ($B3 or B$3) or relative? That is in a spreadsheet that's being working on, data is being added, it's being processed.--Scicurious (talk) 19:03, 17 December 2015 (UTC)[reply]

The distinctions between "absolute" and "relative" references (are those even the right terms?) are complicated. I don't know if I've ever seen the distinctions described completely and understandably; I've kind of worked them out for myself.

About all I can say is that if you've got a spreadsheet where the distinctions matter, you're going to have lots of problems if you ever use an "absolute" reference when you needed a relative one, or vice versa. I can't imagine distilling out a simple rule saying that one or the other form is somehow more (or less) error-prone; that sounds like it would inevitably end up being endlessly misleading advice.

If you or your users are having trouble with this, I would suggest either (a) learning more about the distinctions so that you can remember and use them reliably, or (b) restricting yourself to the simple, regular, homogeneous spreadsheet layouts which don't end up needing "absolute" references at all, meaning that you can always and safely use the "relative" ones. —Steve Summit (talk) 19:34, 17 December 2015 (UTC) [tweaked 13:57, 18 December 2015 (UTC)][reply]

Those are indeed the correct terms, and they have been in use at least since the early days of Lotus 1-2-3. Example here. --LarryMac | Talk 18:08, 18 December 2015 (UTC)[reply]

Thanks! I was skeptical because when you create them and when they're sitting there working, both styles are pretty "absolute" in my book. The difference shows up only -- and as the nicely vintage reference you cited clearly explains -- when formulas containing references are copied to new locations. —Steve Summit (talk) 18:39, 18 December 2015 (UTC)[reply]

My experience is that absolute and relative references have more to do with copy/paste operations than anything else. If it is a relative reference, it changes as you paste. If it is an absolute reference, it doesn't change. So, you choose the one that does what you want. 209.149.113.52 (talk) 15:46, 18 December 2015 (UTC)[reply]

How to deal with wired.meraki.com

On a library computer with Firefox, I have been told the problem is one of updating the version of Firefox. The problem seems to have been at least partly solved.

But on those sites where it hasn't, the screen is white with the words "Connecting to wired.meraki.com" or something similar (probably ads, since the various sites are almost never related to the content I want) for the longest time before the actual content finally shows up. On a library computer with only Internet Explorer, on one of the same sites, there is no such explanation but the screen stays white for a long time.— Vchimpanzee • talk • contributions • 19:46, 17 December 2015 (UTC)[reply]

December 18

Windows 10 drivers

If you have Windows 10 drivers for a device, does that mean that you will never need new drivers as Windows 10 is updated? Bubba73 ^{You talkin' to me?} 04:37, 18 December 2015 (UTC)[reply]

Usually not, but it is not possible to 100% sure. Ruslik_Zero 13:47, 18 December 2015 (UTC)[reply]

The hardware might need or might get a new driver released. This has nothing to do with Windows 10. A new Windows version could break the backwards compatibility with drivers of version pasts, I doubt this could happen with updates within the same version. So, even when Windows moves to Windows 13, your drivers will probably run OK. Windows has also “compatibility mode” options that make the applications believe tehy are running on the old Windows still. --3dcaddy (talk) 18:41, 18 December 2015 (UTC)[reply]

Can't see my 5GHz network

I have a laptop running Windows 7 with a wireless-N adapter (Intel Wireless-N 7260) and a dual-band wireless-N router. The 5GHz network is enabled on the router and set to broadcast SSID. Why can't I see it in the list of networks available for connection? Do all wirelsss-N adapters support the 5GHz band? ―Mandruss ☎ 14:05, 18 December 2015 (UTC)[reply]

No. All wireless N adapters do not support 5GHZ. Many do not. I have five different adapters in my house. Three do support 5ghz and use it. Two do not and don't even see it. 209.149.113.52 (talk) 14:32, 18 December 2015 (UTC)[reply]

Yeah, after a little more online digging, it appears I probably have the single-band version of 7260. Nuts. Stuck with 2.4 for now. ―Mandruss ☎ 14:54, 18 December 2015 (UTC)[reply]

One wireless adapter, two networks

Could one run-of-the-mill wireless adapter connect to two wifi networks at the same time? Mine does not support this, but I wonder where the limitation comes from. --3dcaddy (talk) 18:33, 18 December 2015 (UTC)[reply]

Both Linux and Windows have virtual WiFi projects that claim to allow you to connect to multiple wifi networks with one wireless device. I haven't used either one. The Windows one is here. 209.149.113.52 (talk) 19:03, 18 December 2015 (UTC)[reply]