Wikipedia:Reference desk/Archives/Computing/2016 February 8

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February 8

The Hunting of the Snark

As a young child in the early 1990s, I enjoyed playing a range of little computer games on Grandmother's computer whenever we visited my grandparents; I'm looking for one of them now. It had a title similar to, or identical to, The Hunting of the Snark; you had to find little snark characters in a gridded board (most spaces were empty, a few had snarks, and one had a boojum that ended the game if you found it), presumably findable through some method, but I was young enough that I couldn't find them except by clicking spaces randomly. Can anyone point me to any information about such a game? Google searches produce results mostly related to the namesake original poem, and the game-related things I found were talking about a simple program that you could write in BASIC twenty years earlier, not something that would be sold commercially on par with programs such as Chip's Challenge. Nyttend (talk) 00:42, 8 February 2016 (UTC)

My memory of that game is from much earlier than the 1990s. It would be more around the early 1980s. The source code was in a magazine or on a floppy included with a magazine. Likely, it was Byte magazine. However, all my memories from the 80s are merged together into a heaping pile of big hair, bright colors, and piles of floppy disks. 209.149.115.90 (talk) 19:49, 8 February 2016 (UTC)

To clarify, Nyttend, are you describing a graphic game? Given the amount of shovelware that came with PCs in the 90s, it may be that somebody took the basic (as well as BASIC) Snark game and put a rudimentary graphical front end on it. As you mentioned, Google searches are difficult, not least because of the more modern, colloquial meaning of snark. --LarryMac | Talk 20:27, 8 February 2016 (UTC)

Maybe some variant of Hunt the Wumpus? Some versions had tile graphics [1]. 21:34, 8 February 2016 (UTC)

Yes, a graphic game; at least part of the game, if not all, was controlled by clicking spots with the mouse. Nyttend (talk) 14:49, 12 February 2016 (UTC)

Sounds similar to Minesweeper. All the best: Rich Farmbrough, 02:42, 16 February 2016 (UTC).

Google DNS Server

What could be some caveats or cautions about using Google DNS Server (IP address 8.8.8.8) as my DNS server? Privacy issues, maybe? ←Baseball Bugs ^{What's up, Doc?} carrots→ 05:20, 8 February 2016 (UTC)

There are two issues: performance and privacy.

Privacy: as Infoworld pointed out a while back.[2][3]

"The reality is that Google's business is and has always been about mining as much data as possible to be able to present information to users. After all, it can't display what it doesn't know. Google Search has always been an ad-supported service, so it needs a way to sell those users to advertisers -- that's how the industry works. Its Google Now voice-based service is simply a form of Google Search, so it too serves advertisers' needs. In the digital world, advertisers want to know more than the 100,000 people who might be interested in buying a new car. They now want to know who those people are, so they can reach out to them with custom messages that are more likely to be effective. They may not know you personally, but they know your digital persona -- basically, you. Google needs to know about you to satisfy its advertisers' demands. Once you understand that, you understand why Google does what it does. That's simply its business. Nothing is free, so if you won't pay cash, you'll have to pay with personal information. That business model has been around for decades; Google didn't invent that business model, but Google did figure out how to make it work globally, pervasively, appealingly, and nearly instantaneously."

The question is whether your ISP's DNS servers are worse. Are they selling your information as well? (I am looking at you, AT&T).

Performance: Most major websites use Content Delivery Networks (Amazon, Akamai,,) to serve content. A Content Delivery Network looks up your computer's IP address and directs you to the nearest server. With a public DNS server, the CDN might serve you content from a distant server, and thus your download speeds will thus be slower than if you use your ISP's DNS server. Google's DNS server information page says:

"Note, however, that because nameservers geolocate according to the resolver's IP address rather than the user's, Google Public DNS has the same limitations as other open DNS services: that is, the server to which a user is referred might be farther away than one to which a local DNS provider would have referred. This could cause a slower browsing experience for certain sites"

If you are in Australia, using the US-based Google DNS server means that "closest" Akamai cache will be chosen as in the US and you’ll see very slow download speeds as your file downloads over the international link. It's not as bad in the continental US, but it is still slower.

BTW, wikileaks keeps a list of alternative DNS servers.[4] --Guy Macon (talk) 08:30, 8 February 2016 (UTC)

That information is somewhat outdated, Google supports an extension which can provide your subnet to the CDN's DNS server so they can provide more accurate resolution [5] and it's been enabled at least for Akamai.

Also while the quoted part may be from Google, I'm not certain your intepretation is correct even ignoring the extensions. Talking about US-based Google DNS server from Australia is confusing since both 8.8.8.8 and 8.8.4.4 are anycast addresses. In NZ the servers responding are generally in Australia (you can tell by the latency). I didn't test the IPv6 servers but I'm pretty sure they're the same. I suspect this is normally the case in Australia too, since Google will definitely want their Australian servers to be used for Australians and I doubt many Australian ISPs care enough to fight Google, in fact I strongly suspect Google has the clout that they'll be able to resolve any routing/peering disputes which may cause problems. As a home end user, there's not much you can generally do about routing, so most likely you're going to be sent to the Australian DNS servers in Australia. And I strongly suspect the Australian DNS servers will do lookups with CDN's name servers specific for the Australian servers. That seems to be what this page is saying [6].

In other word, I strongly suspect if you're in Australia it's fairly unlikely you'll be connecting to Google's US DNS and it's also fairly unlikely you'll get US CDNs (unless they're the closest). You may still not get the best CDN's particularly if they don't support the extension. For example, some ISPs work with CDNs to provide specific servers for their customers. Likewise, I have no idea where Google has DNS servers in Australia, do they have them in both Melbourne and Sydney for example? I wouldn't be surprised if som CDNs do which means if Google doesn't you may not get the best geographically located servers even in Australia. Obviously in my case without the extension I'll be getting CDNs in Australia and not NZ even if they exist and there will be countries where the responding name server may be an even worse choice. (It can be complicated but your assumption should be if you're ISP is remotely competent their name servers should provide CDNs that give the best routing.)

One final comment, I'm in NZ not Australia but one our only major internet cable also connects to Australia anyway and I can say things are not nearly as bad as they were 5-10 ears ago. I'm using VDSL2 although the cable to my house is a bit crap or far so only get about 50mbit/s. I can maximise this even connecting to the US, sometimes even at peak times. (In fact, if you're not connecting to a CDN it's easily possible the US server will be faster than the local one.)

It obviously depends significant on the ISP and how much international bandwidth they have, and it's possible NZ ISPs tend to have more because there are fewer CDNs (and I'm not sure where trans-Tasman bandwidth is much cheaper than Californian bandwidth). The SCC is not even close to capacity (and I'm presuming a number of those connected only to Australia are similar), so it is only a cost issue. And it can get confusing what you're actually connecting to because of transparent caching/proxying that many ISPs use. Still the takeaway message is you shouldn't assume connecting to the US is going to be slower (in terms of bandwidth, latency is obviously going to be higher). Of course where it does happen, your ISP won't particularly like you wasting their international bandwidth that way. Actually another reason why it's likely they will work with Google to ensure their customers who choose to use Google Public DNS end up connecting to the right server.

P.S. This assumes that the CDN and your ISP only rely on name servers lookups to ensure you end up on right server. If they have a more complicated system, it may be that you will still end up connected to the right server even if your DNS does their resolutions to the CDN's name servers from the wrong location.

Nil Einne (talk) 13:45, 8 February 2016 (UTC)

Generally, DNS servers can be logged. When using Google Chrome it does not matter on navigating on web pages. The license of Google Chrome makes Google own all input You enter into the URL field of the browser. Other programms can be logged by monitoring the DNS queries. Using a DNS server, You need to trust it. I think You can trust Google. Modifing the DNS entry is also an modification to Your computer. Imagine the cause of a hacked DNS server when using online banking or giving passwords to the page, Your browser displays. DNS servers also can be used as quick way to block (web)servers hosting malware. The DNS entries in Your computer and router tells what “phonebook” to use and the computer will connect to the returned IP address. --Hans Haase (有问题吗) 11:16, 8 February 2016 (UTC)

Thank you, all, for your insights. :) ←Baseball Bugs ^{What's up, Doc?} carrots→ 01:09, 10 February 2016 (UTC)

External hard drive on Windows 10

I've backed up my files from another computer onto an external hard drive. I've connected the hard drive to Windows 10. but there is no obvious way to access it. How do I extract the files? Theskinnytypist (talk) 19:42, 8 February 2016 (UTC)

If you just copied the files over it should be a drag-and-drop copy, with the caveat that you may need to take full control & ownership of the folder first as explained here (instructions are for Windows 7, but are valid for Windows 10). If you used a backup/restore application then you might have to use that same application to restore your backup. If you used Windows 7's backup, it has a specific option in Windows 10 for restoring. FrameDrag (talk) 20:45, 8 February 2016 (UTC)

Battery dying issue

Peeps, I'm having a bit of a problem with the Laptop battery that I bought recently.

1) I bought it before/after christmas. I read the guideline where it stated (in a sentence): "Charge to 100% when it goes to 2% for the first time. For maximum battery life keep the charge up to 70%".

a) I've charged it to 100% as stated by taking it to 2%.

b) I don't really get the time to keep the battery up to 70% then turn it off because I turn on the Laptop then work until it goes to 2% than recharge to 100% while the Laptop stays on, then turn it off for about 15-20 mins, then turn it on again. I do take the occasional breaks e.g., when I'm watching TV or eating, sleeping, showring or when I go out...

c)The battery is dying like an "idiot"!

2) I've not followed any rules whatsoever with my other battery that came with the computer and it lasted four to four and a half years.

Now, I'm confused and worried how the current battery is dying; its already on 17%. What do you guys suggest I should do? Note: I have a warrenty for 6 months too...

Apostle (talk) 22:39, 8 February 2016 (UTC)

There's an option in Win7 and later to only charge the battery to about 80%. Look in the Power Management settings. Repeated partial charges/discharges will wear out the battery quicker than leaving at at 100% charge. LongHairedFop (talk) 19:34, 9 February 2016 (UTC)

for the claim repeated partial discharges is worse than leaving the battery at 100%. The device almost definitely has lithium ion of some sort, and these chemistries tend to work best if you don't store the battery at 100% and don't fully discharge. (Although full discharge cycles tends to help the device give better life estimations.) See http://batteryuniversity .com/learn/article/how_to_prolong_lithium_based_batteries and [7] [8] for example. Nil Einne (talk) 06:03, 10 February 2016 (UTC)

It sounds as if you have a faulty battery. Laptop batteries should last at least three hours from full charge, and some last much longer, though the time will vary according to usage. Try timing how long the battery lasts with continuous usage, then take it back to the store where you bought it. You will have a stronger case to present if you were given some indication of the battery life you could expect at the time of sale. By the way, if you are able to leave the charger attached as you work most of the time, then this will save on long-term battery life by not repeatedly charging and discharging. Dbfirs 20:25, 9 February 2016 (UTC)

Well, its 5200mAh. At first it was giving 5h 13m. Now it just about shows 4h 20 or 30m after a full charge (I have to shut it down then have to turn it back on because the battery dies even quicker if you don't turn it off...). From what I recall, it displays 1h 25m if I'm only using MS Word consisting more than 120 pages... Is it normal?

I found the Power Option settings in the Control Pannel but no option available on how much I could charge up to? I have Window 7 Ultimate Unless my English is not functioning again! - could you guide me please?

Apostle (talk) 22:10, 9 February 2016 (UTC)

Most laptops have control circuitry next to the battery that prevents overcharge, so I can see no reason why you shouldn't leave it on charge well past the 100% reading. Some people claim that you shouldn't leave power connected long-term, but I've always ignored that advice, and the laptop on which I'm typing this has been connected to the power supply almost continuously for over eight years and is still working (though the battery now lasts only a few minutes on its own without external power). The number of pages in MS Word makes negligible difference, but the time editing in Word should be at least four hours before it turns itself off. If you are watching a DVD or running external devices then the time might be shorter. You can turn the screen brightness down a bit to save battery power, and there should be other power options available, but these control how much power is used, not how much to put in. You will find that for every charge and discharge, the time you get from a full charge reduces by up to 0.1%, and this is normal. The calculation of time left is unreliable because it estimates this from current usage and past experience. If your usage varies, the time will go up and down as it recalculates. Dbfirs 22:42, 9 February 2016 (UTC)

The reason you shouldn't leave the power connected long term with the battery is because it reduces battery life. Lithium ion batteries have a significantly shorter life (in terms of how much they charge they can hold over time) if held at 100% state of charge (or 4.2V or higher for the types of lithium ion chemistries most commly used) long term. Also some devices don't disconnect the battery and only use power when fully charged. Instead they use the battery and then topup the charge when it gets below a charge level. (Most devices will also topup the battery anyway although self discharge of lithium ion isn't that high so I admit I'm not sure how much of a difference it makes but it probably makes some.)

Unless the device or battery is seriously defective, it's unlikely the battery will be dangerous if you do keep it at 100%, but if you have a battery the assumption would be you want to use the battery so it would be better to use the device in such a way that you don't shorten the life.

With a laptop, if you plan to use the device on power for a long time, it would be a good idea to remove the battery and only use it on power if you can (although this will mean you could get data loss if there is power loss and you don't have a secondary UPS). Preferable with the battery at around 70% charge. Alternatively fancier laptops may let you limit the charge to ~70% (or 3.9-4V for the types of lithium ion chemistries most commonly used). (If it's an old laptop now used like a desktop perhaps with the battery as a short of UPS, this doesn't matter much.) Note however it can be worse to discharge down to 0%, so if storing it at 70% means you often discharge down to 0% it may be better to store it at 100%. (Again, I admit I'm not completely sure how much of a difference this makes, as in both cases the amount of discharge would I presume be the same but my understanding is most commonly discharging down to 0% is probably a bit worse for battery life than charging up to 100%.)

Nil Einne (talk) 06:03, 10 February 2016 (UTC)

P.S. Most of what I said above is supported by the refs listed above. [9] has some info on capacity variation after storage albeit storage at 55 degrees C. Interesting enough they found 0% is best, whereas the most common recommendation is 30-70%. But I think the reason for that may because if you store the cell at very low SoC, you run the risk it will discharge to a level where it can't safely be used anymore.

Nil Einne (talk) 06:22, 10 February 2016 (UTC)

I don't disagree with anything Nil Einne writes above, but it's all too much bother for me to keep removing the battery. I just assume, perhaps wrongly in view of the linked documents, that the battery control circuitry is intelligent and optimises battery life. The worst thing for Li-ion batteries seems to be high temperature. Perhaps that's why my batteries last longer in cool Cumbria. Dbfirs 19:31, 10 February 2016 (UTC)

The thing is there's an inherent contradiction in consumer demands. While it's true most people want their battery to last a long time, most people also want their device to last a long time during use. So while the manufacturer could likely extend battery lifespan by charging to 4V instead of 4.2V (or whatever), they don't because they would prefer to have the battery hold more charge. Further it's much easier for someone to do a test and find the device only lasts for 5 hours instead of 6h on a single charge than it is for someone to know that after 300 cycles, the battery will still have 90% of capacity instead of 50% (these are made up numbers). Even worse from a consumer POV would be plugging the device into the charger and using it, only to find when they disconnect it's only 60% charged because the device stopped charging and didn't top up the charge after use. I admit I'm not always certain why some devices when plugged and fully charged continue to use the battery rather than just power although particularly with phones I think a significant reason is because the charger may not be able to fully power the phone during high power usage and that this increases complexity of the phone powering circuit for something which may often not be used much. Also as mentioned, I'm not certain this really makes a big difference. What I strongly suspect would be better would be to allow the battery to discharge a bit because while discharging the battery also effects the battery's ability to hold capacity, it's probably better than continuing to hold it at 100%. But as mentioned, few people want to take their device off power only to find it's only at 60% capacity because the device used the battery and didn't top it up. Or to put it a different way, the charging circuitry is smart but it's not magic and from the manufacturer POV, the first big concern is safety and the second big concern is getting maximum life from a fresh battery and ensuring the device behaves the way the customer expects. Maximum life after 2 years is below all that (and may be even other concerns) on the list of priorities. Nil Einne (talk) 17:04, 11 February 2016 (UTC)

Yes, that analysis sounds exactly right. Dbfirs 18:18, 11 February 2016 (UTC)

Okay guys, this is my experience with this current battery (this doesn't mean the same will apply with all of you):

Say for example you let the battery die out completely - this is very bad. If you fully charge the battery and still use it after unplugging - very bad for the battery. Also, a heavy usage without on recharge mode - very bad for the battery.

Now, I'll try the theory of 70%. See if it works... Thank you all for trying to help. Regards.

Apostle (talk) 18:30, 10 February 2016 (UTC)

I'm not sure why fully charge the battery and still use it after unplugging would be very bad, except in so far as a charge and discharge reduces battery capacity by 0.1%. Let us know how your experiment goes. Dbfirs 18:18, 11 February 2016 (UTC)

I'm using Everest software to review the mWh. Yesterday/Today I found out that, (1) you have to switch off the Laptop twice (not sure at what percentage) after starting at fully charged; you have to keep it off for about less than an hour or so though. Point (1) did not work twice before so I'm guessing it depends on the percentage you shut your Laptop off... (2) I also tried to use the laptop till to its last point after full charge than recharging it to full after viewing the last warning (after the notification) - two-three times it worked than floped out (reduces the mWh). What you stated earlier about the battery trying to replicate the timing of last time was correct. Also, do not keep it on charge even after its fully charged. Do not put it on sleep or hybernate mode - they are for Desktops only, not for battery usage PC. Also its doesn't go by 0.1%, goes around about, starting from 647mWh - again depending on the usage... And yes, charge and discharge reduces the mWh too if the Computer is on. I'll update you guys if it doesn't go down...keep it between all us Wikipedians! -- Apostle (talk) 19:39, 11 February 2016 (UTC)