Wikipedia:Reference desk/Archives/Computing/2013 June 8

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June 8

Will mini data computers/visors/commicators like in Robocop ever exist?

Venustar84 (talk) 00:57, 8 June 2013 (UTC)

Note: I've modified your link formatting to make it easier to use for other editors, and marked the links that don't work. Looie496 (talk) 01:36, 8 June 2013 (UTC)

Your first "diagram" link is to nothing more than a Google search with several images shown. As for the visor, we nearly have that now with Google Glass. And what does Robocop have to do with Sailor Moon? Dismas|^(talk) 01:55, 8 June 2013 (UTC)

With the same level of accuracy/reliability? Right now, they do not exist, and we are not here to make future predictions. OsmanRF34 (talk) 15:54, 8 June 2013 (UTC)

captcha and security

Is it normal and commonsensical for a University page to put captcha asking for the sum of a pair of two digit numbers (like this) on page where students should look for their examination results? Apart from limiting the number of queries what purpose it can serve? They say it is for security reasons. How can this aid in enhancing security? --Thenjipalam (talk) 02:30, 8 June 2013 (UTC)

I've fixed your link The purpose of that is to keep people from finding out other people's scores by trying one number after another until they find one that works. If they do it in an automated way, they could cycle through numbers very quickly. There are other ways of defending against that sort of thing, but most of them are more work for the programmers. Looie496 (talk) 02:46, 8 June 2013 (UTC)

Let's say there's some program that scans the web trying to make copies of private data like this. It might even be good at deciphering normal captchas. However, even if it can read the numbers, it won't know that it's supposed to sum them and enter the result. Most likely it will just supply the individual numbers and be rejected. You'd need a human involved to read the instructions and translate those into computer code. So, this is an extra level of security to stop bots from getting at the data. StuRat (talk) 03:42, 8 June 2013 (UTC)

Some forums use these sort of thing as well. I've seen others which ask you to give the letter number X in some word. Some include statements like 'do not' or similar. As StuRat and Looie496 mention, these primarily rely on the inability of a general purpose bot to understand such statements. Most of them appear to be somewhat easy to defeat if a special purpose bot is used, generally you don't even need to OCR, although they still need more work than without which would likely defeat many attackers. This is somewhat different from normal CAPTCHAs which aim to be difficult even for a special purpose bot although this sometimes mean they are difficult for humans too, particularly perhaps with the increasingly sophisticated OCR. Normal CAPTCHA's are also not particularly accessible unless they have an audio option which should help those with visual impairments whereas something like these sort of things may work with a screenreader. In countries with stronger privacy laws and universities with their own strong privacy policies, none of this is likely to be sufficient. Access to results will generally require some sort of login, in other words a password or access code which is supposed to be secret in addition to the student ID or account name which may be less so. In some places, even posting lists of results by ID in labs etc, let alone name or anything of that sort is not allowed. Nil Einne (talk) 17:51, 8 June 2013 (UTC)

IE8 sans-serif font problem

After updating some fonts on XP, I found that IE8 has turned to a different default sans-serif font for webpages that only specify font-family: sans-serif; (including Wikipedia). It was using Lucida Sans Unicode instead of Arial. After some searching, it was adviced to delete the offending font (temporary) to force IE back to use Arial. However, it switched to Microsoft Sans Serif instead. Repeating the procudere now causes IE to use Candara(!). I cannot find any reference on how IE chooses or stores its default sans-serif font, let alone on how to restore Arial. Does anyone know how to force IE back to using Arial for sans-serif? — Edokter (talk) — 11:12, 8 June 2013 (UTC)

Unknown DHCP client showing up?

I have a password-protected (WPA2) wireless home network broadcasting with a dlink b/g/n router with a hidden SSID. A few days ago, I saw an unknown device under the "Networks Settings" panel of my router control panel under the "Number of Dynamic DHCP Clients" section. I went ahead and blocked its MAC address and then clicked revoke. Now, the same unknown device "SipuraSPA" showed up again and it still has the same MAC address, so it means that it should still be blocked and denied access to the internet right? Do I need to worry about it? Just because it is connected as a DHCP client, does it mean that it has access to the internet? Acceptable (talk) 18:14, 8 June 2013 (UTC)

Incidentally a SipuraSPA3000 seems to be an analog telephone adapter (you may have the Linksys variant), one of those gadgets that lets you plug an existing analog phone into it, and it allows you to do VOIP. Looking at the photos of it on Commons (commons:File:Sipura_SPA-3000_rear.jpeg et al) and this guide it looks like a wired ethernet, not wifi device. -- Finlay McWalterჷTalk 19:45, 8 June 2013 (UTC)

Swallowing micro SD card, will it still work after?

Suppose I find myself in a situation where I want to preserve the data on a microSD card at all costs and choose to swallow the card for later ejecting/retrieval. Will the data on the card still be salvageable after I defecate it out? Acceptable (talk) 18:40, 8 June 2013 (UTC)

If you want to preserve the data at all costs, probably swallowing it is not a good idea. Instead keep it in a secure and protected location. Do you mean in a case where you expect the card to be confiscated or stolen if you don't hide it and you don't have the opportunity to choose a better location? Note that ths question isn't totally a nitpick, swallowing the card may not necessarily be a good idea even from a preserving data POV depending on how you expect your adversaries to respond if they either see it happening or don't find one in the device. And this goes both ways. If you expect to be searched internally in some way, then somewhere else may be better particularly if you are in a location where you don't expect you adversary can spend a great time in. Or since I would guess there is some chance of damage or loss, if no great effort is likely then hiding it somewhere else if possible, perhaps internally without swallowing may be better. This is slightly in reverse [1], where recovery was made but that was likely not the intention of the person swallowing the card. But it does highlight the point that if the adversary had wanted to destroy the data, swallowing it would have made little difference in a case like that. I've even seem suggestions that with a not particularly technical inclined adversary who may however be willing to go to some lengths if they think you are hiding a card, a semi destructive process like formatting but not wiping or overwriting the card may work. (In such a case, swallowing it may be counter productive.) Of course this also depends on stuff like whether you can fool them in some other way, perhaps a spare card [2]. Note that on the earlier point on formatting combined with the point on damage, it also raises another issue namely what sort of resources you have for recovery. E.g. There are some suggestions that recovery was made from a chewed card here [3] this sort of thing advanced recovery is probably available albeit at a significant cost to most people from professional recovery services but otherwise would likely be beyond most people's skill set. Nil Einne (talk) 19:06, 8 June 2013 (UTC)

I would probably set up a dummy card for them to discover; though if they decide to check the contents, then you're out of luck! --Yellow1996 (talk) 17:22, 9 June 2013 (UTC)

I wouldn’t want to bet on all the materials of an SD card making it through stomach acid alright (though it'd be easy enough to test), but you could certainly encase the card in something that would protect it from the acid with a high degree of certainty. ¦ Reisio (talk) 18:28, 10 June 2013 (UTC)

How to make printer online?

How to make a printer online instead of being offline? the printer model is Brothers-HL-2270DW series. — Preceding unsigned comment added by 70.54.64.134 (talk) 20:40, 8 June 2013 (UTC)

I don't quite understand. Do you just want to get the printer to print, or are you trying to put it on a network so it can be used to print from other PCs ? In either case, we need to know about your PC, too, such as the operating system. StuRat (talk) 21:50, 8 June 2013 (UTC)

The OP could also be referring to "Online" as in "On" (many printers will show a status of "Offline" on the computer if the machine itself is not turned on); If this is the case, then it could be that there is something wrong with the printer or it's software that is causing it to show up as "Offline" rather than "Online." --Yellow1996 (talk) 18:05, 9 June 2013 (UTC)

Power issues in using a laptop from Portugal in Canada/US ?

I'm looking into having a laptop shipped from Portugal to the US/Canada (I believe the US and Canada use the same power system). It currently runs on 220V, but would need to run on 110V. Does this just mean replacing the cord/wall wart ? StuRat (talk) 21:55, 8 June 2013 (UTC)

It's rare for a laptop's external power supply to not be a switched-mode power supply that can cope with 220 or 110 transparently. Usually one need only adapt the plug itself, either with a travel adaptor or by changing the mains-side cable (many have a IEC 60320 C5/C6 connector. -- Finlay McWalterჷTalk 22:01, 8 June 2013 (UTC)

OK, so you don't always replace the cord/wall wart, you just plug it into an adapter, which then plugs into the wall outlet ? StuRat (talk) 15:44, 9 June 2013 (UTC)

Correct. Given that laptops are intended, at least in part, for business travellers who expect to be able to use it wherever in the world their business takes them, a dumb non-switching laptop power brick would be be a serious demerit. To be sure, check the voltage range written on the sticker on the power adapter. The laptop itself gets something like 12, 20, or 24V DC from the power brick, usually on a non-standard (even between models from the same manufacturer) coaxial connector. -- Finlay McWalterჷTalk 17:55, 9 June 2013 (UTC)

Yes, a plug adaptor is usually the cheapest solution (or cutting off the old plug and wiring a new one if you are competent to do this). Most power "bricks" seem to be happy with any input between 100 and 250 volts (and the most common output of 19 volts DC), but check yours (when you get it) to make sure. Dbfirs 07:30, 10 June 2013 (UTC)

OK, thanks all. StuRat (talk) 03:23, 11 June 2013 (UTC)

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