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November 13

Table headers in datasheet

I am currently loking at this datasheet from Atmel. There are a couple of tables describing the contents of the device's EEPROM (tables E-1 and F-1) whose column headers' contents look like 0_h / 8_h. The byte address for each row is a range of eight bytes. I can understand using 0h through 7h to divide the row, but why is each number paired with a second hexadecimal digit that is 8 greater than itself? — Melab±1 ☎ 03:10, 13 November 2015 (UTC)[reply]

My guess is the / means "or", meaning, for example, the byte values at addresses F000h and F008h are always the same. However, this doesn't seem to be explained in the document, so I'm not sure. I notice there are other tables in Appendix E (tables E-6, E-8, and E-10) that only label the columns as 0h to 7h. Maybe this suggests you only need to use addresses ending in 0h to 7h to access the data values in table E-1 (and table F-1?). --Bavi H (talk) 04:52, 13 November 2015 (UTC)[reply]

Oops. I originally thought the row headers were ranges of 16 bytes (F000h - F00Fh). Now I see the row headers are only ranges of 8 bytes each (F000h - F007h). I'm more confident the / means "or": For the first row labeled F000h - F007h, the columns represent addresses ending 0h to 7h. For the second row labeled F008h - F00Fh, the columns represent addresses ending in 8h to Fh, and so on. --Bavi H (talk) 05:20, 13 November 2015 (UTC)[reply]

Spam that involves short sentences and one misspelling?

A spam bot has cropped up at GlyphWiki with bizarre edit summaries and weirder edit contents (this is a wiki that hosts designs of Chinese characters). Searching "Way to use the internet to help people solve prblsemo!" (one of the "messages" left behind) in Google shows that GlyphWiki is not alone. What purpose does such a bizarre attack have? What's the single misspelling in the message for? Do the cryptic edit summaries mean anything? —suzukaze (t・c) 05:27, 13 November 2015 (UTC)[reply]

About the misspelling, it could randomly swap some letters in a sentence it sends out to millions, in an attempt to evade automatic blocking software looking for a particular sentence. StuRat (talk) 06:43, 13 November 2015 (UTC)[reply]

The thing to remember is that computers are stupid. Most spambots aren't very complex. They just look for any HTML form and submit spam. They're going for quantity over quality. Especially looking at this page, I think this particular bot is more oriented towards comment sections. These kinds of bots often stick spam links in the name or title fields of comments. Since Mediawiki isn't a blog platform with comments, it might be sticking spam links in the submit data for these nonexistent fields, so the links never get posted. --71.119.131.184 (talk) 08:33, 13 November 2015 (UTC)[reply]

I looked at a site once by a guy who hated Wikipedia. He developed tools to bypass the CAPTCHA so you could create and use multiple accounts automatically. I also saw an auto-editor on his site that copies previous edit summaries and slightly misspells them so they won't look, to the computer, like duplicates. When I looked at it, he had a few other tools, but was mainly working on one where you give it some copyrighted text and a Wikipedia article. It would then alter one sentence at a time, each time with a different account, over a long period of time. It would turn the Wikipedia article into the copyrighted article. That appeared to be his purpose - making articles on Wikipedia copyright infringement. I assume that someone else could develop similar tools to put spam in pages or, perhaps, use his editor tool but instead of making article copyrighted, they add spam. I've been Googling, but I keep coming back to a user here on Wikipedia who doesn't have a user page anymore. I haven't found his website. 209.149.114.132 (talk) 13:39, 13 November 2015 (UTC)[reply]

Diff 563404424 is still in the Wikipedia history, even if Google can't find it. One may hope that our old friend has since recanted - at least the parts pertaining to intentional, automated vandalism. Nimur (talk) 16:33, 13 November 2015 (UTC)[reply]

I wouldn't call that an "old friend." 162.211.46.242 (talk) 20:32, 16 November 2015 (UTC)[reply]

I believe you're looking at XRumer with its distinctive edit summaries. These are designed to provide any value for input fields. The misspellings usually come from a highly developed list of alternatives, designed to avoid filters and spam detectors. The general conversation it adds is used to supply some SEO context. You can expect these edits to be followed up with some real spam. -- zzuuzz ^(talk) 14:08, 13 November 2015 (UTC)[reply]

Is there some sort of problem with GMail?

Lately I have been sending pictures of people I have taken photographs of to their own respective e-mail addresses. Pretty much everyone has had a GMail address. So far, I have extremely seldom received a reply. All this makes me worried whether the mails are getting there in the first place, especially as e-mail is a connectionless protocol. The mails have been in the order of 20 to 30 MB each. I have received mailer-daemon replies from GMail if I send too large mails, or mails to addresses which don't exist, but I extremely seldom get a reply from anyone I send a mail to. Is there some sort of problem with GMail, or do people simply have too little time or energy to reply to my mails? JIP | Talk 21:02, 13 November 2015 (UTC)[reply]

Why not email them and ask if they got the photo? Or ask if they have too little time or energy to reply to your mails? GangofOne (talk) 21:45, 13 November 2015 (UTC)[reply]

That's what I've been thinking about too, but in case they have received my mails and just haven't replied, I fear I might come across as pushy or nosy. JIP | Talk 23:47, 14 November 2015 (UTC)[reply]

How about - "I've accidentally deleted the photo I sent you - could you send me a copy?" If they didn't get it, you can tell them it's not important - and if they don't reply, your question is answered. Tevildo (talk) 01:04, 15 November 2015 (UTC)[reply]

Check out Sidekick, I use it and it tracks when an email is opened and by whom if sent to multiple people, and lets you know. Integrates with Chrome and Gmail seamlessly. RegistryKey^(RegEdit) 22:00, 15 November 2015 (UTC)[reply]

It's also possible you send so much stuff to everyone they just tuned you out. I have a relative who sends me a dozen forwarded emails a day, and I no longer bother opening them. I haven't actually blocked them, and do look at the titles, but others might choose to block them. StuRat (talk) 17:48, 16 November 2015 (UTC)[reply]

If someone sends me an email and doesn't specifically ask for a reply, and I have no other reason to reply, I don't reply. Certainly I never bother replying just to say "thanks I got your email". If you WANT to know if people are getting the photos you are sending, you should just ask, please reply if you got this picture. Vespine (talk) 22:57, 17 November 2015 (UTC)[reply]

November 15

Slow running Win 7 laptop

I am having troubles with my ≈4.5 year old Toshiba Windows 7 laptop, almost randomly, running 'slow' and even 'locking up'.
This is possibly due to my bad habit of running several browser windows with multiple tabs in each.
• I also usually hibernate the laptop after use and only reboot it after days of use. (or when it won't respond!)
• Right now Task Manager says I'm running about

-120 processes. (Is that excessive?)

- 81% physical memory,

- CPU 10%

• Laptop config is:

Windows 7 Home Premium 64 bit (service pack 1)
Intel i3-2310m Processor (quad core)
4Gb RAM
750 Gb HDD (55% free)
Geforce 315M video

I sometimes seem to be using a lot of memory like 95% for not doing much. Irregularly the usage seems to go right up ↑ for no obvious reason. Sometimes when I kill a few browsers tbas it will drop ↓ abruptly and the laptop become responsive again, but sometimes I can't even close a browser, without a significant wait!
• Any suggestions? 220 of ^Borg 17:45, 15 November 2015 (UTC)[reply]

The number of processes and memory use are not remarkably high. Which browser do you user? When the laptop freezes is it actively using the hard drive? Ruslik_Zero 20:04, 15 November 2015 (UTC)[reply]

When was the last time you cleaned the dust out of it? Over the years I've seen a number of people complaining about issues with laptops where it turned out the entire thing was crammed full of dust, causing overheating, which causes the system to run slowly and/or crash. --71.119.131.184 (talk) 21:27, 15 November 2015 (UTC)[reply]

The browser I was using at the time was Chrome. I sometimes switch to Firefox (usually after a 'crash'). The laptop was repaired about 15 months ago, HDD replaced after dying after about 2.5(?) years usage.

• They did include a note about dust, but IIRC that was standard practice. I have been watching the temperature gauge (cpu temp?), and it seems to indicate correct temperature. Doesn't seem to happen while playing games, makes me suspect a browser issue. I have checked the inlets & exhaust are clear, but haven't opened it up to check. Now it is well out of warranty, so likely a good idea

• I have previously received a warning about the HDD thrashing, perhaps I got ripped off with the replacement HDD? My window experience index dropped from 5.6 to 5.1 after repair, and last night I ran the test again and it dropped to 4.9!

• ~~I have an SD card that I think is configured to be used as cache memory, maybe that's a problem.~~ No, that's been disabled .
I'm on my tablet now so no quick access to more PC info. -220 of ^Borg 23:45, 15 November 2015 (UTC)[reply]

I would reboot more often (at least daily). That clears out old processes wasting CPU time. (See if you notice it being faster right after a reboot.) StuRat (talk) 17:45, 16 November 2015 (UTC)[reply]

Not generally necessary. My 6 GB RAM Vista box currently has uptime of 380 hours and runs perfectly well. I probably reboot less than once evert 6 months. My 1 GB Windows 7 netbook regularly runs slowly and is automatically rebooted twice a week to free up memory. So - if you have enough, a reboot is not really necessary.--Phil Holmes (talk) 18:28, 16 November 2015 (UTC)[reply]

The RAM is only part of the story. If one of your processes has a memory leak (which seems quite common in Windows from my experience), it will soon fill your RAM, no matter how much you have. You may just be lucky enough not to have any memory leaks. StuRat (talk) 06:11, 17 November 2015 (UTC)[reply]

StuRat interestingly, I actually had a forced reboot via a BSOD about 12 hours ago. Makes me concerned about the HDD as that's the sort of thing that happened last time it 'died'. It does reduce the memory usage, but there still seems to be peculiar spikes in that. I may have to post a screenshot so you can see what I mean. 220 of ^Borg 02:44, 17 November 2015 (UTC)[reply]

I'm hesitant to say that 4GB of RAM isn't really enough in this age of software bloat, but that's the only real problem I see with the setup. Have you considered purchasing more RAM? FrameDrag (talk) 20:23, 16 November 2015 (UTC)[reply]

Money is very tight right now. I have lots of RAM, just not laptop type! What would another 4GB cost? 220 of ^Borg 02:44, 17 November 2015 (UTC)[reply]

• Any ideas about the magically dropping Windows experience figure? 220 of ^Borg 02:44, 17 November 2015 (UTC)[reply]

Recently on my laptop I found a windows update hanging and causing a memory leak, leading to all the symptoms you describe. It wasn't easy to find but the utility I found at processhacker.sourceforge.net helped. Sandman1142 (talk) 08:39, 17 November 2015 (UTC)[reply]

Updates? That's something I haven't done recently. 220 of ^Borg 11:39, 17 November 2015 (UTC)[reply]

November 16

What makes cosine similarity useful for classifying documents?

Why use the cosine similarity to know how similar two documents are? That is, (A * B) / (||A|| * ||B||). A and B are sequences of word frequencies.

Couldn't you just make a table of words + frequencies for each document and subtract the value of doc A from the value of doc B? More differences in these would imply more general difference. That is A - B, A and B are sequences of word frequencies. --3dcaddy (talk) 19:01, 16 November 2015 (UTC)[reply]

You need some historical background for a complete answer... The Jaccard index (also known as a coefficient) was popular for measuring similarity and diversity among two different sets. Flowers are used often as an example of Jaccard index. My set might contain color and length of stem. Yours might have color and number of pedals. We compare based on what we both have and get a measure of similarity. It is also important to note that Jaccard index handles sparsity very well. If I forgot to write down color for half the flowers in my set, it still works for those that actually have data. Next... what if we are working strictly with binary data. Every field is a yes/no answer. It is still two sets containing different columns and there is still a lot of sparsity. The Tanimoto coefficient is an algebraic form of the set theory Jaccard index for binary sets. It is popular and common. But, it has some overhead that can be simplified. If you know the algebraic form of cosine, you will see that it is very similar to the Tanimoto formula. So, why not throw out the complexity and use cosine instead? You nearly get the Tanimoto coefficient, which is the same as the Jaccard index for binary sets. Jaccard index is already accepted, so using cosine is nearly accepted. That is the history. Why do we not just count the differences? If I say the differences count up to 132, what does that mean? Nothing really. You need to confine the answer to a range so I know the minimum and maximum values. We know that cosine is -1 to 1. If you tell me the different is 1, that is the max value. I only have to ask if the 1 means absolutely different or absolutely the same. By convention, 1 means absolutely the same and 0 means completely different (-1 means the exact opposite, but that makes no sense in most examples). If that doesn't answer the question, please ask for what I missed. I don't want to flood you with even more details that you don't think are pertinent. 162.211.46.242 (talk) 20:31, 16 November 2015 (UTC)[reply]

The short version: Each document is modeled as a vector in a high-dimensional vector space. When you have two vectors that point in nearly the same direction, they are more "similar" than vectors that are orthogonal or antiparallel, or just point in rather different directions. See also document modelling. (or maybe not, that's a rather pitiful stub) SemanticMantis (talk) 21:33, 16 November 2015 (UTC)[reply]

Thanks for the answers, now I get it. It didn't realize that counting the number of differences, instead of finding a range of values, was quite off the track. Is there any literature about such issues, that intuitively make sense, but are mathematically no-good? --3dcaddy (talk) 21:42, 16 November 2015 (UTC)[reply]

SemanticMantis is correct. Cosine similarity is strictly the cosine of the angle between the two vectors. The relative vector lengths are ignored. If you analyze the Tanimoto formula, you will recognize that it takes into account the distance between the end-points of the vectors. So, if the angle is 10 degrees, cosine is always the cosine of 10 degrees. With Tanimoto, if the vector lengths are nearly the same, the distance between the end points will be near minimal and give me a higher similarity value. If one vector is much longer than the other, the angle remains the same, but the distance between the end points is much longer and the similarity is reduced. If the cosine similarity is good enough for you, then use it. If it turns out that some vectors are extremely long and others are extremely short, you will want to use Tanimoto difference to account for that aspect of measuring similarity. Then, if you are still refining your algorithms, you can look into SVD (which I personally don't like) or convert your data into ordered strings and make a big jump into string-based similarity. 209.149.115.177 (talk) 14:50, 17 November 2015 (UTC)[reply]

Super Mario Maker

After watching YouTube videos of Super Mario Maker, I've become interested in actually buying a Wii U just to play it. It would be the first video game made in the last two decades that I would actually consider buying.

However, I'm afraid I've fallen hopelessly out of touch of modern video games. The last time I bought new video games, they were on real, physical, honest-to-gosh floppy disks put inside a nice, beautiful cardboard box I could take home, open up, and put into my computer.

I figure that these days, actual physical storage media is like Soooo last millennium! What are you, Methusalem?. So, how would I actually go about buying and installing the game? JIP | Talk 19:25, 16 November 2015 (UTC)[reply]

You can either buy a physical Wii U Optical Disc retail, or you can download from the Nintendo eShop. -- Finlay McWalterᚠTalk 19:34, 16 November 2015 (UTC)[reply]

In case a physical disc isn't available, how would I go about downloading it? Can I do it solely using the Wii U? I already have a wired (i.e. non-wireless) broadband Internet connection, which I'm using right now to write this message. Can I use that on the Wii U? Does it have an Ethernet cable connection? How do I pay for it? Can I just use my credit card or do I have to set up some sort of new-fangled subscription account? JIP | Talk 19:40, 16 November 2015 (UTC)[reply]

The Wii U doesn't have an ethernet port, and most people use its Wifi capability; if you can't do that, you can buy a USB Wii LAN adapter which plugs into the Wii U's ethernet port. You can use a credit card with the eShop (and maybe a debit card); you can also buy physical gift cards (they're just plastic cards with numbers on them) in supermarkets which give eShop credit. -- Finlay McWalterᚠTalk 20:05, 16 November 2015 (UTC)[reply]

You said both "the Wii U doesn't have an ethernet port and "plugs into the Wii U's ethernet port". Which is it? Or did you mean "the Wii U's USB port"? In any case, I might be better off finally buying and installing a WiFi device in my apartment. So far I've had no use for one as the only Internet-capable device I ever use is my computer, which uses the wired Internet connection, which I presume is both faster and more secure than a WiFi connection. JIP | Talk 20:23, 16 November 2015 (UTC)[reply]

Oops, yes, I meant USB port. It's just a usb<->ethernet dongle. I see them for about £10 on Amazon. -- Finlay McWalterᚠTalk 20:29, 16 November 2015 (UTC)[reply]

Furthermore, once I get it, I'd like to play other people's levels. Can these be downloaded free of charge or are there additional charges for them? JIP | Talk 19:42, 16 November 2015 (UTC)[reply]

As I understand it, when someone is finished designing a level they tell others the level's ID code (where the ID is a 16-hex-digit number). Here's an example of people posting their IDs in the SuperMarioMaker reddit: https://www.reddit.com/r/MarioMaker/comments/3t164h/level_of_the_week_8_factory_submissions_last/ -- Finlay McWalterᚠTalk 20:09, 16 November 2015 (UTC)[reply]

(edit conflict) There's also the 10 Mario/100 Mario Challenge which chooses several levels at random from the ones users have uploaded, and you have either 10 or 100 lives to get through them all (or skip ones that might be very difficult). I believe that after playing each level it saves snapshots of those levels in your game so that you can look at them in the level designer afterward. FrameDrag (talk) 20:19, 16 November 2015 (UTC)[reply]

You might appreciate SuperBunnyHop's review of a bunch of SMM levels submitted to him here. I think it gives a reasonable idea about what is, and crucially what isn't, possible in SMM. As constructing-stuff-in-the-game type games go, it looks to be considerably inferior to Little Big Planet and especially Minecraft. -- Finlay McWalterᚠTalk 20:13, 16 November 2015 (UTC)[reply]

Wii U is intended to be easy and idiot proof, and it succeeds admirably at those goals. You will have no problems buying (officially licensed) games as physical media or online. For inspiration on SMM, see Bananasaurus Rex's playthrough of this insane level [1] :) SemanticMantis (talk) 21:30, 16 November 2015 (UTC)[reply]

November 17

Laptop

Whenever I close my laptop, the computer will do the same thing that happens when hitting the "print screen" button, namely copy an image of the screen to the clipboard. Does this also happen on your laptop? GeoffreyT2000 (talk) 02:28, 17 November 2015 (UTC)[reply]

no. Vespine (talk) 02:33, 17 November 2015 (UTC)[reply]

Could be something physically hitting the Print Screen button. StuRat (talk) 06:14, 17 November 2015 (UTC)[reply]

Laptops usually have a setting for what to do when the laptop is closed, such as "turn off the screen" or "log off". It is possible someone changed that to "print screen" just to be annoying. 209.149.115.177 (talk) 14:52, 17 November 2015 (UTC)[reply]

Detecting that a folder contains unreachable files or folders due to deep nesting

Windows has a limit of 255 characters imits for path names according to [2]. It's fairly easy when copying or renaming folders, to get in a situation where some of your data is unreachable by ordinary means because this limit has been exceeded. The previously quoted source says robocopy can bypass this limitation. Another trick is to use the subst command from a windows shell to create an alias for a reachable folder with unreachable sub-folders, and access the nested material using the alias.

My question: Is it possible to test beforehand whether a folder contains sub-folders or files with names that exceed the name length? I ask because I would like to avoid starting time-consuming tasks that are bound to fail and possibly mess things up (zip + move). --NorwegianBlue^talk 13:08, 17 November 2015 (UTC)[reply]

Best bet would be writing a Python or PowerShell (or whatever language you're comfortable with) script to recurse through all the folders in a tree and keep track of the max path length as you go. This thread has a Visual Basic (ugh) script for doing this.

The other option is to move the files elsewhere before you begin said task, to shorten the length of the paths; depending on what you're doing this for, though, that may not be possible. FrameDrag (talk) 14:42, 17 November 2015 (UTC)[reply]

The claim that Windows limits path names to 255 characters is not correct or authoritative. Microsoft's documentation, Naming Files, Paths, and Namespaces, explains that maximum path length is file-system-dependent. Certain programmatic functions in the Windows API are limited to use strings of length MAX_PATH, which is 260 characters; but most built-in utilities (including Explorer and the command prompt) are able to use extended path names, with lengths of about 32,000 characters. This has been true of all Windows operating systems for about 20 years - including Windows NT, Windows 95, and Windows CE - so unless you're using a very old system like Windows 3.1, or Windows for Workgroups, or some other ancient software, you do not need to limit path names based on the MAX_PATH limitation. When you write C or C++ code to the Windows API, if you choose to use legacy path functions, you need to be aware of these limits; but you can always use newer APIs to access the file system. If you aren't writing C or C++, (or otherwise directly linking the Windows API), you should probably ignore the "260 character" limit completely, because it doesn't apply. The shell and the individual file system may have different limitations, but this MAX_PATH is not one of them.

Nimur (talk) 16:23, 17 November 2015 (UTC)[reply]

You've misunderstood the documentation. Almost all Windows programs are limited to 260-character paths (259 + trailing NUL), including .NET programs, and there's no sign of that changing in the future. -- BenRG (talk) 18:27, 17 November 2015 (UTC)[reply]

"The Windows API has many functions that also have Unicode versions to permit an extended-length path for a maximum total path length of 32,767 characters." Maximum Path Length Limitation. I think you are conflating two different limitations: limits that are intentionally imposed by specific programs, and limits that are enforced by the operating system itself. Nimur (talk) 20:51, 17 November 2015 (UTC)[reply]

Maybe you misunderstood the quoted sentence to mean that any program that uses the Unicode API supports long paths. That's not the case. Long paths are only supported in a \\?\ prefixed form which doesn't follow the usual Win32 rules (for example the . and .. pseudo-directories aren't supported). Some software will work if you pass it a \\?\ path and it doesn't inspect it too closely, but software that understands and reliably supports long paths is rare. It is indeed a limit of "specific programs", not the kernel, but the "specific programs" include almost every program that has ever been written for 32-bit or 64-bit Windows.

(Cygwin 1.7+ is a notable exception; you can probably safely use long paths in a pure Cygwin environment.) -- BenRG (talk) 00:06, 18 November 2015 (UTC)[reply]

I'm not exactly sure where you got that by reading that MSDN page, I got a completely different read out of it. It says that normal X:\ path names are limited to 260 characters (X:\ + path + NUL terminator), and that \\?\ path names are (probably) limited to the file system limit. It also says that the filesystem itself and the shell are separate, and that it's possible to create perfectly valid things that the shell can't interpret correctly. It's also worth noting that the question wasn't about the char limit... FrameDrag (talk) 20:21, 17 November 2015 (UTC)[reply]

Thanks for your replies! I did some experimenting based on the assumption that Nimur's assertion was correct, before reading the discussion. Here's what I found:

It was possible to create and traverse hierarchies that are deeper than 260 characters with explorer (Windows 7). I created the hierarchy by unzipping a deep hierarchy twice (i.e. nested within itself).
However, there was some weirdness when I crossed the 260 character limit. For one thing, when I tried to text-copy (ctr-C) a folder name presented in the explorer address bar, it changed to old DOS 8-character long-name represesentation when I clicked the address bar, thus preserving a path name shorter than 260 characters, like so:

T:\AD-HER~1\HENVEN~1\2012-0~2\TAKKTI~1\XYZ-TE~1\Brukere\N\nblue\MINEDO~1\MI\HENVEN~1\2012-0~2\Takk til Kristoffer, med nye versjoner\Ny mappe

The full version of the path name in this case would have had 385 characters.

When trying to create new files or folders (in a directory that was beyond the limit) by right-clicking, nothing appeared to happen. However, when I pressed F5, it turned out that the folder or file had been created with the default name, but the gui hadn't been updated.
In cmd.exe, chdir with an argument longer than the 260-character limit failed. If I went step-by-step to the deepest "legal" directory, I could show the next level with "dir", but I couldn't chdir to a directory which gave a path name longer than the limit. I could, however, access the directory via explorer and start a shell with shift-click. But then, the path name was shown as above (T:\AD-HER~1\... etc).
dir /b /s failed with an error message when it reached a folder that was nested too deeply.
When I right-clicked the root folder and selected "properties", only the files that were below the limit appeared to be counted, ditto for the disk space used.
7-zip (current stable version, which is from 2010) was able to successfully compress the entire hierarchy, preserving full-size names at each level, and to decompress it without error messages and with no obvious errors.
I also did an experiment that turned out to provide an answer to my original question. I tried to compress the folder to a zip-file using the built-in Windows mechanism (right clicking and selecting "send to compressed folder"). And voilá - an immediate error message reporting the first file name that was too long. So the question is answered, at least for Windows-7. Unfortunately, the problem that prompted the question occured on an XP machine that needs to be maintained (don't ask)....

-NorwegianBlue^talk 22:29, 17 November 2015 (UTC)[reply]

Resolved

@NorwegianBlue: - I'd be interested (as a smug Linux rubbernecker) whether the failures you got with chdir and dir in cmd.exe also happen if you run them in Powershell. I would hazard that they do not. -- Finlay McWalterᚠTalk 22:39, 17 November 2015 (UTC)[reply]

For what it's worth, TCC/LE, a freeware almost-compatible replacement for cmd.exe, appears to support long paths. PowerShell 2.0 appears not to, but it's rather old. I can't find any clear information about newer PowerShell versions online. -- BenRG (talk) 00:06, 18 November 2015 (UTC)[reply]

(Also, chdir is never going to work because the Win32 "current directory" is just a string that's prepended to partial paths by the Win32 parsing code that \\?\ bypasses. Windows just doesn't support long current directories.) -- BenRG (talk) 00:25, 18 November 2015 (UTC)[reply]

@Finlay McWalter: - As BenRG predicted, powershell 2.0 failed in a similar (and slightly worse) manner than cmd.exe did. From the most deeply nested reachable directory, cmd.exe was able to list the files and folders of the next level. Powershell, however, only echoed the name of the current directory. --NorwegianBlue^talk 07:30, 18 November 2015 (UTC)[reply]

Scanner won't open

My Epson scanner won't open when I click the icon on my computer. I can turn it on but that's it. What could be the problem?--Jeanne Boleyn (talk) 13:24, 17 November 2015 (UTC)[reply]

In technical terms, your scanner is f*cked. Try reinstalling it. If that doesn't work try installing it on a different computer. if that doesn't work, chuck it out. Vespine (talk) 21:51, 17 November 2015 (UTC)[reply]

You can always try unplugging it and plugging it in again. Rebooting the computer may overcome trouble too. Graeme Bartlett (talk) 22:36, 17 November 2015 (UTC)[reply]

Moving data from one secondary SSD to a larger one

I've just purchased a 500GB SSD and I'd like to copy the data from my 240GB SSD (drive letter D currently) to it. Normally I'd just add the drive in but I've actually run out of SATA ports on my motherboard so an upgrade will have to do. Will anything bad happen if I just plug both drives in (unplugging another one temoprarily) and just copy all the data across, then unplug the original and give the new drive the drive letter D? I have installed programs but no OS installed to the drive. 81.138.15.171 (talk) 17:03, 17 November 2015 (UTC)[reply]

Nothing bad should happen (standard disclaimers apply), but if you want to be certain a kit like this (many different ones available, search around for the one that suits you best) makes cloning a disk almost painless. WegianWarrior (talk) 18:45, 17 November 2015 (UTC)[reply]

The installed programs may not appreciate being transferred between drives because of registry issues, and you might have to reinstall them, depending on how the program identifies where it is in the registry. Won't know that until you try it, unfortunately. Also, make sure you turn off your computer before swapping the drives. SATA does support hot-swap in the specification but it depends on your SATA controller as to if it's actually supported. Drive cloning as mentioned above would be a mostly one-click process, but still might have the registry problems. Keyword in all this is 'might.' It also might go completely fine without any problems whatsoever. Obligatory make-sure-to-backup-important-data message here. FrameDrag (talk) 20:27, 17 November 2015 (UTC)[reply]

Another alternative for Windows 7 and above is to back up your existing SSD to another drive with enough free space, swap SSDs, format, and restore. Alternatively, SATA controller add-in cards are dirt cheap. I recently put this $20 card in a PC that didn't have enough sata ports and it works fine. --Guy Macon (talk) 21:40, 17 November 2015 (UTC)[reply]

Linux hard disk questions

Because of circumstances beyond my control, I no longer have the right to use the Windows drive that was in the computer my company gave me. I can keep the actual computer though, so I have physically removed the drive. Fedora 20 Linux boots up happily without it, but I still see "Windows Boot Manager" in the boot menu even though the computer is now 100% Bill-free. How do I get rid of it?

This has also given me an empty drive bay. Assuming I buy another hard drive, can I somehow have one partition, or one mount point, span both drives, part of one and the total of another, or part of one and part of another? I think I must have asked this question earlier but I have forgot the answers. JIP | Talk 18:08, 17 November 2015 (UTC)[reply]

The issue will be what boot manager you are running. If it is grub2 (F20 default), you can see the grub.conf file usually in /boot/grub2/grun.conf. It looks like a mess, but it is rather easy to find each kernel that it will load. You can delete the one you don't want. I know that there are tools to edit the grub.conf file, but I don't use them, so I cannot explain how to use them. As for spanning multiple disks, that is what LVM is used for. Again, this is default for F20. Both disks become a volume that you, the user, sees as a single drive. My suggestion is to backup all the files you really want to keep. Then, put in a second drive. Then, install the latest Fedora from disk and tell it to completely format and reuse all drive space. You'll quickly end up with a single logical volume over two disks and the boot manager will be cleaned up. 209.149.115.177 (talk) 18:37, 17 November 2015 (UTC)[reply]

I think that when I fill up my current drive, I can buy another two drives and keep the old one as a backup. I can then install the latest Fedora release on the new drives and use LVM on them. Is it possible to have LVM only use part of one drive and the whole of another? How is it controlled which files end up on which drive if they're the same logical partition? Or will the files themselves be spread out across the drives, with part of a file lying on one drive and part on another? What happens if I remove one drive? Can I still access the remaining drive's files or will the whole LVM system fail? If I migrate the drives themselves to another computer, is it enough to plug them both in somewhere? Do I have to boot the computer from the LVM drives for LVM to work or will it somehow automatically work even if I boot from a normal singular drive? JIP | Talk 19:13, 17 November 2015 (UTC)[reply]

LVM merges partitions into single logical volume. You don't really have much control over where files go (there are advanced LVM settings, but I don't play with them). So, you can partition a single drive into two partitions and only use one of those partitions in a logical volume. The cool thing about LVM is that you can remove and add partitions whenever you like. I had a disk that was reporting too many bad sectors. I removed it from the LVM (which took time, but automatically removed all data from the failing drive). Then, I added a new drive to the LVM. My file system was, from my point of view, the same (technically bigger). I also solved a problem we had using LVM. We had a JBOD with 24TB of disk space in it. We kept getting file corruption. After a hell of a lot of research, I highly suspected the size of the disks. It reported as a single 24TB partition. So, I broke it into 6 4TB partitions on the JBOD side. I didn't lose much data storage - just a very minor amount for the partition overhead. Then, on the server side, I merged the 6 partitions into a single logical volume. After a year of monthly (or more often) file corruption, we ran for the next two years without a single corrupt file. The users still saw the 24TB "disk", which was actually a volume of 6 partitions. 209.149.115.177 (talk) 19:45, 17 November 2015 (UTC)[reply]

So, as I understand it, LVM divides files between the drives but doesn't actually spread out individual files, and I don't get to choose what files go where. But I didn't really see a reply to my other questions. Is an LVM drive or partition only accessible through LVM, or can it be mounted as a standard drive or partition and whatever files there are can be accessed? Do LVM drives or partitions automatically know they're under LVM and so all I have to do is to plug them in and they're accessible through LVM? How do I actually add or remove a drive in LVM? Does a drive under LVM obey the normal file system structure or does LVM have its own file system? Is an LVM drive accessible if I don't plug in all of the drives under LVM? In particular, I want to know whether an LVM drive can be accessed without LVM, and whether installing LVM drives to a new system is as simple as just plugging the drives in. JIP | Talk 20:15, 17 November 2015 (UTC)[reply]

LVM is part of Fedora. You may already be using it. Run "sudo lvdisplay" to see what logical volumes you have. I only have one drive in my computer I'm using right now, but it has a logical volume wrapping the single user partition on that drive. The volume is what the OS sees as a "drive". You can format the volume with whatever filesystem you like. It is just a drive. All in all, it is another level of abstraction. You have the physical disk. Above that, you have partitions. Each partition is a separate "drive" even though they are all one physical disk. Volumes treat multiple partitions as single drives. To get technical, it gets down to block mapping. Block 82 of my logical volume will be mapped to, say Block 129 of one of the partitions in the volume. But, that partition is part of a physical drive. Block 129 of the partition may be block 2031 on the physical drive. You (and your files) don't know about the indirection. They just know about the volume because the filesystem resides on the volume. So, assume you are using something simple like a file allocation table based filesystem. You have a file allocated to blocks 153 to 187. Those are logical volume blocks. You don't control which partition owns those blocks or what block they are on the partition. You can do advanced settings, but I don't mess with that. As for messing with volumes, you use the lv* commands (I'm sure there's a GUI also). There is lvcreate, lvdisplay, lvextend, lvremove, lvresize -- just off the top of my head. I'm sure there are more lv commands. In the end, you won't notice you are using logical volumes until you decide to mess with the volumes. Otherwise, they are just drives built into the Fedora's file management system. 209.149.115.177 (talk) 20:49, 17 November 2015 (UTC)[reply]

I'm finally getting my head around all this. So LVM is not about actually storing the files, but about accessing them? The files get stored as normal files under normal file systems, but LVM is just there to let me access all of them via a single mount point? JIP | Talk 21:07, 17 November 2015 (UTC)[reply]

That is mostly correct. When you merge a partition into an volume, the partition will be formatted by the logical volume manager to be part of the volume. You can't take a drive out of a logical volume and slap it into another computer. It no longer is independent. It is a dedicated part of a volume. This is very similar to RAID. If a partition is part of a RAID 5 volume, you cannot take a single drive out of it and use it elsewhere. So, it is not like taking a bunch of independent drives that work fine by themselves and putting them under one mount point. It is merging the filesystem of a bunch of drives so they are dependent on one another. As such, they become a single mount point. 75.139.70.50 (talk) 23:30, 17 November 2015 (UTC)[reply]

I'm fairly sure I use grub2, because it's the F20 default. I don't remember choosing any alternative boot manager. I have a /boot/grub2 directory but there is no grub.conf file there. locate grub.conf didn't find it either. JIP | Talk 19:16, 17 November 2015 (UTC)[reply]

Mine is in /boot/grub2/grub.cfg - I think I typo'd with grub.conf earlier. 209.149.115.177 (talk) 19:45, 17 November 2015 (UTC)[reply]

Mine is in /boot/efi/EFI/fedora/grub.cfg; it depends on whether your machine uses UEFI or not. --70.49.170.168 (talk) 19:50, 17 November 2015 (UTC)[reply]

I did find /boot/efi/EFI/fedora/grub.cfg, and there is a line in it for "Windows Boot Manager". But at the last moment, I chickened out from editing the file. If I make any errors, could it cause grub2 to fail and make my system unbootable, and therefore pretty much unusable? JIP | Talk 20:26, 17 November 2015 (UTC)[reply]

I don't use a GUI or special "helpers". I Googled and "grubby" appears to a tool Fedora has to alter the grub.cfg file without manually editing it. 75.139.70.50 (talk) 23:30, 17 November 2015 (UTC)[reply]

Open alternatives to Kindle

As I understand it Kindle is very snoopy and DRMy. Is there an alternative? Or can I jail-break a Kindle?
All the best: Rich Farmbrough, 20:53, 17 November 2015 (UTC).[reply]

Defective by Design's list of DRM-free ebook suppliers is here. -- Finlay McWalterᚠTalk 23:18, 17 November 2015 (UTC)[reply]

Kindle is a tablet. There are many tablets on the market that aren't locked down by Amazon. Many are cheaper than a Kindle. If you are talking about the Kindle Reader app. You can get many books in PDF form and read them with any PDF reader you like. If you are talking about Kindle books, there are programs that you can use to convert those to PDF documents. It isn't the easiest thing to do, but it exists. 75.139.70.50 (talk) 23:32, 17 November 2015 (UTC)[reply]

Try one of the Kobo eReaders. Instructions for Building The Kobo Reader Sources are here. --Guy Macon (talk) 00:07, 18 November 2015 (UTC)[reply]

Fairly sure the OP is referring to the Amazon Kindle eReader devices, which aren't tablets under most common definitions. And there aren't that many eink/epaper or eink/epaper like devices any more (well there never was but they more common than tablets at one time). There is however more than the Kindle. Kobo is the most obvious example, but there's also the Nook, a bunch of Hanvon devices and others. The Mobiread forums [3] and wiki [4] are a good source of information for such devices. There are even some with Android, but I'm not sure if it's really a good choice. Amazon does seem to be going down the route of Apple, and making it difficult for users to get full control over their devices, e.g. [5] [6].

Note however, depending on precisely which version you're looking at (including ad supported or not), where you live and whether Amazon is having one of their regular specials, you'll probably find most of these devices are at best comparable in price to Amazon devices, not cheaper.

PDF is a fairly bad format for most fiction eBooks since it's designed for fixed-layout which is unnecessary and means the book generally only works well on certain screen sizes. Likewise the ability to change font size etc (a big advantage with ebooks) is limited. PDF should only really be used for ebooks when fixed-layout is needed such as with text books, picture books, journal articles etc, although even there there are alternatives for fixed layout.

EPUB which is an ISO standard is probably the only common standard ebook format that's somewhat open and used by pretty much everyone other than Amazon. (The latest versions also support fixed-layout and may be where picture books and possibly text books will move. Although as I understand it epub 3 is very complicated format, hence why it's taken so long for even the full featured commercial rendering engine.)

However most ebooks in ePub format from commercial sources have DRM. In some countries you can legally remove this DRM if you own a licence for the book. OTOH in some countries such as the US with DMCA or similar laws with anti-circumvention clauses, you're potentially breaking the law (as in criminal matter rather than a civil matter between you and the copyright owner) if you do so for most purposes regardless of what licence you have (enabling the book to work with text to speech tools may be one exception in the US, but I'm not certain).

If you're able to remove the DRM, it's relatively easy on a computer for a number of DRM formats. This BTW includes the DRM Amazon uses in the Kindle books. Also I believe Apple FairPlay DRM (never done it myself but what I've read suggests it's possible). And perhaps the key one is Adobe Digital Editions DRM which many epub vendors including I believe Google Play, Barnes & Noble and Kobo support for transferring to other ereaders (their own devices sometimes use different DRM).

While the popular library management application Calibre refuses to official support DRM-removal in any way, there are plugins that can be added that after set-up mean you can basically just import the book like normal (not sure about Apple). Calibre BTW also has fairly good automatic conversion between ebook formats. It can even often fix ebooks which are unnecessarily PDFs (or otherwise fixed layout) although your best bet is to avoid them. (Calibre can also handle TXT, saved HTML, RTF, DOC, older formats like LIT, actually pretty much anything you're likely to encounter. Albeit with the possibility some formatting may be lost, or you may get some weird stuff on particularly poorly made sources.) So with some minor technical competence, actually dealing with DRMed ebooks isn't generally that different from non DRMed ones. And likewise you may not have to care whether your books are from Amazon or someone else, which may not match your device. (If you're in the US, this may be an advantage because from what I've read Amazon often has the cheapest ebooks, although as mentioned if you're in the US the DMCA may cause problems.)

Note that most commercially sourced PDF eBooks are DRM protected too, so it's not like getting PDFs allays DRM concerns. Also most ereaders including Amazon's do support DRM free ebooks in the formats they support for DRMed ebooks, if you get them from somewhere (be it originally like that or with the DRM removed). Obviously with Amazon their lack of support for epub means conversions may be necessary (although as mentioned is generally easy). However the Kindle devices are popular enough that MOBI and KF8 books are also very common. E.g. Humble Bundle DRM-free fiction ebooks generally provide both Mobi and EPUB, and possibly PDF [7] [8].

BTW, if you do have a tablet, there are plenty of ereader apps on both Android and Apple Store, and even Windows Store, which support proper ebook formats like epub or Mobi (probably both if they aren't vendor apps). Likewise on most laptop/desktop OSes. So there's never any real reason to use a fixed layout format like PDF for ebooks, where it isn't needed by the book.

Nil Einne (talk) 12:45, 18 November 2015 (UTC)[reply]

November 18

Computer systems that handle leap seconds honestly?

As noted in our article, Unix time (the well-known seconds-since-1970 scheme) is "no[t] a true representation of UTC". This is because it makes no formal provision for leap seconds, and in fact some rather dreadful kludges are necessary at midnight on leap second days in order to handle leap seconds at all (and there have also been some rather dreadful bugs).

My question is, does anyone know of an operating system (mainstream or not) that is able to handle UTC leap seconds up-front and properly? By "up-front and properly" I mean that

the kernel-level clock runs for 86,401 true seconds on a leap-second day (analogously to the way a true and proper calendar runs for 29 whole days in February during leap years), without having to do anything kludgey
a user-level program that prints the time of day (perhaps after fetching a time_t value from the OS, perhaps after using a C library function like ctime or localtime) will actually print a time like "23:59:60" (as illustrated on our leap second page)

In terms of the well-known, mainstream operating systems, as far as I know, all versions of Unix, Linux, and Microsoft Windows fail both of these tests. (I'm not sure about MacOS.) —Steve Summit (talk) 01:42, 18 November 2015 (UTC)[reply]

The tz database has time zones under right/ that count leap seconds, and I think that you can get a value of 60 in tm_sec (which is permitted by POSIX) if you use one of those. But actually using them appears to violate POSIX. -- BenRG (talk) 04:14, 18 November 2015 (UTC)[reply]

It is a lot more complicated than simply defining one possible behavior as "handling leap seconds honestly" when the defined behavior implies that when doing a conversion from seconds_since_epoch value to a time in hours/minutes/seconds the computer has to give one of two possible hours/minutes/seconds answers for a particular seconds_since_epoch value and then one second later convert the exact same seconds_since_epoch value and convert it into a different hours/minutes/seconds value -- and the conversion has to (by psychic powers?) pick the right answer even converting a stored seconds_since_epoch value. See [ http://www.madore.org/~david/computers/unix-leap-seconds.html ] Also, this definition of "handling leap seconds honestly" is completely unable to handle them "honestly" for dates and times a few years in the future because we have no idea when leap seconds will be added or subtracted. See [ http://www.wired.com/2015/01/torvalds_leapsecond/ ]. --Guy Macon (talk) 12:38, 18 November 2015 (UTC)[reply]

Windows 7

Can I copy my disk version of windows 7 to another drive in case my first drive fails? --31.55.64.160 (talk) 02:52, 18 November 2015 (UTC)[reply]

Sure, if you use Disk cloning software like Clonezilla. FrameDrag (talk) 12:55, 18 November 2015 (UTC)[reply]

How do I create a website with an unusual URL extension?

I see a lot of weird URL extensions on this website: https://iwantmyname.com/domains/new-gtld-domain-extensions I'm just not 100% sure what's the process behind these unusual URLs as opposed to just using dot com. Are they free for everyone to use, or did this company somehow gain exclusive rights to them? Can I buy a website through, say, WordPress or GoDaddy and just use a weird suffix? 2605:6000:EDC9:7B00:8C5C:47A8:2805:69A7 (talk) 03:59, 18 November 2015 (UTC)[reply]

The "URL extensions" are top-level domains. Ultimately ICANN decides what TLDs can exist. They've chosen to do this by soliciting proposals from private parties, with a $185,000 application fee, and with the submitting party getting control of the domain if it's approved. The benefit for ICANN appears to be that they make tons of money (more than 1000 applications according to this, so over $185 million in fees). The benefit for winners is that they get to collect fees from registrants; it's probably especially lucrative for broad domains like .biz or .app where many companies will feel they have to register their trademarks just to protect them. The benefit to everyone else is unclear. But yes, you can buy subdomains of the new TLDs, from the controlling entity or a reseller, for a price ranging from cheap to thousands of dollars. -- BenRG (talk) 05:51, 18 November 2015 (UTC)[reply]