Wikipedia:Reference desk/Archives/Computing/2016 February 23

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February 23

Pausing applications

Does anyone know of a way to pause applications on a PC (Win10)? There was a program called uPause a few years ago, but I don't know if it went anywhere. — kwami (talk) 05:01, 23 February 2016 (UTC)

Well, there is the old keyboard "Pause/Break" key, on the upper right corner of my keyboard. That's mostly an obsolete key left over from mainframe days, but I've occasionally been surprised to find some modern application that obeys it (along with the Scroll Lock key right next to it). StuRat (talk) 05:29, 23 February 2016 (UTC)

Never thought of that. Thanks. — kwami (talk) 00:37, 24 February 2016 (UTC)

You can suspend a process with, for example, Process Hacker (right-click on the process and choose "Suspend"). This will prevent it from using the CPU until you resume it. pssuspend does the same thing from the command line. -- BenRG (talk) 07:48, 23 February 2016 (UTC)

That should work, e.g. if a program can't run because s.t. else is using all the CPU. Thanks! — kwami (talk) 00:37, 24 February 2016 (UTC)

@BenRG: Do you know of other programs like Process Hacker? That will only pause the program I want for 20 seconds, and I need something longer. — kwami (talk) 02:03, 28 February 2016 (UTC)

Process Hacker doesn't have a 20-second timeout. If the process is auto-resuming after 20 seconds, a separate watchdog process may have noticed that it stopped responding and restarted it. What application are you trying to pause? -- BenRG (talk) 06:30, 28 February 2016 (UTC)

A question about RAM

When computers got 1GB of RAM (Random Access Memory) for the first time? 192.114.23.208 (talk) 09:34, 23 February 2016 (UTC)

Time computers often claim to have the first home computer to hit 1GB RAM. The problem is that they put out the hardware with an OS that couldn't access 1GB of RAM. Super computers obviously hit that much earlier, but they do not have the same design as average computers, so they tend to measure memory in words, such as "1 million words of memory." You can translate that to bytes (e.g. if a word is 32 bytes, 1 million words is 32MB). Because memory is not used in the same way, that comparison doesn't really make a lot of sense. 209.149.114.211 (talk) 13:34, 23 February 2016 (UTC)

The 1985 Cray-2 had an unprecedented 2GB of RAM in the biggest configuration, and I think that was a giant and unprecedented leap at the time. The predecessor Cray XMP had no more than 64 MB at the time (it got up to 256 MB with the Extended Architecture, but that was later). --Stephan Schulz (talk) 18:19, 23 February 2016 (UTC)

Computer memory part

How many part of computer memory and how it work adn what is the imortant each of one? By Aanaya, — Preceding unsigned comment added by Scalemodel (talk • contribs) 09:53, 23 February 2016 (UTC)

See Random Access Memory. The Quixotic Potato (talk) 10:11, 23 February 2016 (UTC)

What is the Windows Alt code for ∼ (not ~)?

I would like the Alt code (e.g. Alt + 0176 for °) for ∼. Note that this is not a tilde ~ for which finding the Alt code is trivial using Google. They appear quite similar in some fonts and distinct in others. Thanks! ----Seans Potato Business 20:40, 23 February 2016 (UTC)

It doesn't have an Alt code. The Quixotic Potato (talk) 21:23, 23 February 2016 (UTC)

Interestingly enough, the first symbol ∼ redirects to proportionality (mathematics) while the tilde ~ goes to tilde (characters enlarged to show texture :) Wiktionary [1] has some confusion on the issue, but they are confused as to what is and isn't a tilde too [2]. This link [3] is different from this link [4]. In LaTeX the first character is accessed via \sim, like so: $\sim$, and in HTML it is '&sim'. I have no idea if any of this helps but it may help future responders. I don't know what determines if a character gets an alt code, but it does seem that a few sources want to consider the "tilde operator" (for lack of a better term) as distinct from a vanilla "tilde". SemanticMantis (talk) 22:08, 23 February 2016 (UTC)

To directly answer the original question: the use of Alt key plus numeric-keypad only works for ASCII. "∼" is a valid Unicode character, but it is not a valid ASCII character. You cannot enter it using such a keyboard shortcut on Windows.

There's tons of precedent for the use of a distinct Unicode code point (or a code point in any other text encoding scheme), even if the glyph is very similar or exactly identical. Whether it is a good idea to use esoteric code-points is often debated - particularly when it impacts human-readability or security. (See, for example, homographic spoofing, e.g. confusing O and O). This is a weird problem: semantic information is being scattered between the code-point, the recommended glyph, and the font; however, application-software users can choose the code-point and the font. That means that some users will see identical glyphs; others will see dramatically different glyphs; ... problems abound with this strange entangling of concerns, because your user's default font choice can destroy semantic meaning that you intentionally added to your document!

So, if you really truthfully care about the difference between ∼ and ~, you should be very careful. Think hard about why you want to use the other character. Think about whether your users expect to distinguish these characters. Think about whether you expect your users to be able to tell the difference - both graphically and semantically. Consider how the characters will behave when the reader is a machine, rather than a person.

Nimur (talk) 23:11, 23 February 2016 (UTC)

I read in [a post on Reddit] that ∼ was the appropriate symbol to use as an indication of approximation. In the font Calibri, the tilde ~ appears high and so I want to use ∼ but can find no better alternative than copying and pasting it from that Reddit post or wherever else I may have saved or posted it. --Seans Potato Business 10:55, 24 February 2016 (UTC)

Windows does actually support entering in Unicode characters using alt, it's just not enabled by default and requires editing the registry or using a tool which does it for you. See Unicode input#In Microsoft Windows for more. Nil Einne (talk) 11:07, 24 February 2016 (UTC)

Thanks a lot, Nil! :) --Seans Potato Business 14:22, 24 February 2016 (UTC)

Don't feel bad about cutting and pasting special characters from a list somewhere. That's what I do all the time, myself (even for "ordinary" special characters like '¢'), because in the end it's way easier than remembering what the special keystroke combination is this week. —Steve Summit (talk) 15:57, 24 February 2016 (UTC)

Also this is an interesting example of eventually getting to a helpful response, starting from the "wrong" question :) SemanticMantis (talk) 16:38, 24 February 2016 (UTC)

BTW alternatives ways to input unicode on Windows include third party tools [5] and the Unicode IME [6] provided for certain languages. You can also always use the Character Map which should be available on most default Windows installs unless your administrator really, really locked things down. Well according to our article, the later only works for plane 0 but I think that applies to quite a few of the input methods. Nil Einne (talk) 14:10, 26 February 2016 (UTC)

Actually strike the bit about Character Map. I think the specific symbol is one that is hidden in character map. Alternatively it was just absent in the two fonts I tried. Also since it doesn't seem to have been mentioned, albeit covered in our article and the wiktionary article, ∼ is U+223C. [7] has some info on recommended use mathematics although our article also covers this. Based on that source and comparing our Proportionality (mathematics) and tilde articles, I've changed the redirect to tilde. Nil Einne (talk) 14:34, 26 February 2016 (UTC)

Just a note about naming. The character used as a diacrtical on the letter "n" in Spanish is a tilde. The character sometimes used to indicate proportionality or approximation, which in proper typography is larger than a tilde, is a swung dash. --69.159.9.222 (talk) 06:03, 25 February 2016 (UTC)

Hmm according to that article, our tilde article and at least one other source I've seen, the character we're discussing here is called the tilde operator ∼ and is used in mathematics related areas. The swung dash ⁓ is a different symbol used in dictionaries and similar. BTW, in unicode, if your character doesn't already have a tilde, I'm pretty sure you're supposed to use ◌̃ not ~ although both are tildes. Although possibly depending on your layout engine you may use ˜?. Nil Einne (talk) 14:45, 26 February 2016 (UTC)