Wikipedia:Reference desk/Archives/Computing/2016 January 26

= January 26 =

What are these function keys on my keyboard for?
What are these function keys on my keyboard for? One is "F11" and one is "F12". The "F11" key has a little icon of Microsoft Word on it. The "F12" key has a little icon of Microsoft Excel on it. So, what are those function keys supposed to do? I use Microsoft Word and Excel all the time. So, I'd like to know if these function keys will be helpful or useful to me. If it matters, I have a Logitech keyboard. The Model Number is MK 700 / MK 710. Here is a photograph of it:. If you click on the photo, the photo will become enlarged. And you can see exactly what I am referring to. Thanks. Joseph A. Spadaro (talk) 05:14, 26 January 2016 (UTC)


 * Here is the manual for that model: Getting started with Logitech Wireless Desktop MK710. According to the manual, if you have installed the "Logitech SetPoint" software, then pressing the FN and F11 buttons together will launch a "document application" and pressing FN and F12 together will launch a "spreadsheet application". Later in the manual the customizing screens of the software are shown, and it looks like you can change the FN+F# combos to open any file or program. --Bavi H (talk) 06:04, 26 January 2016 (UTC)
 * See also Function key for an overview.--Shantavira|feed me 08:52, 26 January 2016 (UTC)


 * The general idea is that those keys can be used to key in keyboard shortcuts. While the GUI is seen as easy to learn an use, many heavy computer users (and all before the mouse) find that they can do things much more quickly if they can keep their hands on the keyboard instead of reaching for a mouse every few seconds. See our Table_of_keyboard_shortcuts, which says that F11, pressed by itself, should toggle the current window between fullscreen and "normal" sized. There are operating system-level shortcuts (for things like window manipulation, quitting programs, etc) as well as application-level shortcuts. So the same shortcut can and will do different things in different applications, and the same maneuver can require different shortcuts in different applications. If you want to know more about how to use shortcuts in e.g. Word, here's a handy reference "cheat sheet", and you can find many, many more by searching things like /[application name] keyboard shortcut [sheet/list]/. It may seem like a lot of effort to memorize these, but for any program that you use a lot, the shortcuts will save you hours per month, and if you truly use a command a lot, you'll quickly memorize it within a few days of taping up your cheat sheet. Here's a few research articles on the topic of keyboard shortcuts that you might like to skim . SemanticMantis (talk) 21:15, 26 January 2016 (UTC)


 * I dunno. Seems like an awful lot of trouble.  For very-little-to-no benefit.  When I want to open Word or Excel, I do one click of the mouse on my desktop.  Actually, on my task bar.  So, that's hardly burdensome.  Not sure why I (or anyone) would ever need a "short cut" to something that is simply one step (merely one click) and takes literally less than one second.  Odd.   Joseph A. Spadaro (talk) 04:14, 27 January 2016 (UTC)


 * Opening Word or Excel may not be the most useful shortcut, but if you don't have a mouse in your hand, it will definitely take longer than one second unless you move your hand so fast to risk causing injury. Particularly if it isn't on the taskbar. If you use Word or Excel often enough to use the shortcut, perhaps it's worth having on the taskbar but perhaps not, people manage their computers differently and have different tolerance for clutter. Note also that the comment from Bavi H suggests up to 12 programs which is quite a lot to add to your task bar. (Of course some people just don't know about pinning stuff to the taskbar or use an OS where this isn't possible.) Not sure what you mean by an awful lot of trouble. Opening a program using such a shortcut will take less than second for all Fn+F# if both hands are on the keyboard. If only one hand is (and most people probably have at least one hand when actively using the computer), then depending on where the Fn is (AFAIK most keyboards have a single key on the left) perhaps about half. You could optimise this by choosing programs you're likely to be touch typing with that require both hands. Of course you can use other keys as your shortcut keys. Unless you have memoriy issue. Learning simple shortcuts like which key to open which program should take less than a day if you use them regular, less than a week if somewhat irregular. (If you're using them so irregular that you don't learn in a week, probably the shortcut key isn't worth it.) Nil Einne (talk) 12:40, 27 January 2016 (UTC)
 * Also worth noting that shortcuts are a bit of a subjective taste, and their rewards are much greater for a so-called power user who wants/needs to make excel dance and sing, compared to a user who just wants to do simple things occasionally. I agree with Joseph that an application-opening button is not so great, in isolation. Especially since if you use excel frequently, then you only open them rarely. I suspect the symbol on the keyboard was an attempt to idiot proof the thing, but it fails because it requires the Fn key, and not just a simple press, so the functionality is opaque to the proverbial idiot. Personally, I think shortcuts are great for everybody, but then again, I roll my eyes when people tell me I should start writing more shell scripts to automate various tasks I do... SemanticMantis (talk) 14:14, 27 January 2016 (UTC)


 * A few of the function keys have more or less standard meanings. F1 is almost always Help.  It should bring up Help for whatever application you are focused on.  F3 is usually Exit or Escape.  I don't know without looking up whether any of the other function keys have standard meanings.  Robert McClenon (talk) 00:16, 28 January 2016 (UTC)

Thanks, all. Joseph A. Spadaro (talk) 19:48, 28 January 2016 (UTC)

Confused About Diodes
I'm trying to build the circuit described here in order to add a Pause button to my SEGA Master System controller: http://www.smspower.org/Development/JoypadPauseButton. It ties the output from a logic gate to the processor's non-maskable interrupt pin (NMI), which is how the system already implements the pause function. The idea is be able to pause the game from the controller, instead of having to press the button on the console (which is several feet away). The web page says this:


 * "Important: The diode (not shown) has to be placed between pin 4 (cathode) and the wire to pin 22 of the VDP, to prevent the real pause button to fry the gate's output. Another solution can be simply cutting the ground pin of the pause button, making it ineffective."

Ok, fair enough. I wired a diode between the gate's output and the NMI pin. It is biased so that current will only flow from the gate output to the NMI pin. Now, when I send the pause signal, the output gate is pulled low (yay!), but the NMI pin isn't, because the logic level doesn't "pass through" the diode to the pin (i.e. my logic probe doesn't give a reading). I actually tried this first without the diode, but then the gate output wasn't defined.

So, it sounds like the diode is there to make sure the current can only flow from the gate output to the pin, but that's not what's happening. I guess I could have the diode backwards, but my multimeter's diode check function says that's not the case. Any thoughts on what I'm doing wrong? OldTimeNESter (talk) 18:11, 26 January 2016 (UTC)
 * What we have here is a wired-OR circuit using negative logic, so the diodes want to be the opposite way round to the diagram in the wired-OR article. The diode should be arranged so that current can flow from the NMI input to the gate output, so that when the gate output goes low, the NMI pin is pulled low.  If the NMI pin is being pulled low by the existing circuit, no current will flow through the diode, so the gate won't be trying to drive a short-circuit.  The description in the source instructions is correct - the cathode of the diode wants to go to the gate output.  It sounds as though you have the anode connected to the gate output, instead. Tevildo (talk) 18:49, 26 January 2016 (UTC)
 * You're right, that did it. I also had to wire it to the video chip (like the instructions say) instead of directly to the CPU. I have zero idea why you can't wire it directly, or why the pause circuit involves the video chip at all (unlike the NES, the SMS doesn't use the NMI to trigger vertical blanking) but it kept reading an indeterminate logic level until I switched it. Thanks for the quick response, and the helpful links! OldTimeNESter (talk) 02:56, 27 January 2016 (UTC)
 * Without the diode, when the original pause button is pressed, the output of the new gate is shorted to ground. Although this won't damage it immediately, it won't do it any good - if your chip is a real 74LS02, it's only recommended to short the outputs for 1 second. Tevildo (talk) 06:59, 27 January 2016 (UTC)
 * For technical background, see computer keyboard and search for "matrix" in the article text. -- Hans Haase (有问题吗) 12:47, 28 January 2016 (UTC)

Saving a worksheet with filters applied
This may seem to be a naive question to many (or may be not). Anyway, I am not an advanced user of spreadsheets, so please be in detail.

Suppose I create a worksheet in MS Excel with filters applied to a column. Now I want to save the file only with the filtered data which is appearing presently, sych that the rest of the data is deleted. In other words, If I send it to someone, say via email, the recepient should not be able to remove the filter and see the entire content. Copy-paste, I believe, doesn't work because when you select a range, the intermediate rows (not showing on screen) are also selected and then copied. Is there any way to do that? Jazzy Prinker (talk) 18:44, 26 January 2016 (UTC)


 * Here's instructions to copy visible cells only, and not the hidden stuff. I think the best thing to do is to paste the filtered data into a new file, and send that to others, rather than deleting your original data that you might later want. SemanticMantis (talk) 21:51, 26 January 2016 (UTC)


 * Thank you so much. That's exactly what I needed. Jazzy Prinker (talk) 04:57, 27 January 2016 (UTC)

Tooltips for editing wikipedia
I'm just learning how to edit wikipedia and was hoping there was a way to get more info from the tooltips. Anything I hover over just tells me to click it to insert the markup without explaining what it does.

The reason for my question is because I made a mistake making references on the science ref desk, which somebody else had to correct for me. I know there is the sandbox for experimenting, but if the tooltips could, for example, tell me what I'm going to click is going to make a reference at the bottom of the page, or an external link, etc. that would be very useful to newcomers like myself.

I've tried the VisualEditor, but it seems quite limited, maybe only useful for making minor changes to pages? But my question is about more help from tooltips, I can't imagine it would take much work to update them to help out more, but I'm not a programmer or web guru so I may be totally wrong. Thanks Mike Dhu (talk) 22:37, 26 January 2016 (UTC)


 * Hi! For questions about editing, you want the Help desk or Teahouse. The Reference Desk is for general knowledge questions. Other resources for help: Help:Contents, New contributors' help page. --71.119.131.184 (talk) 00:49, 27 January 2016 (UTC)


 * Another place to post this would be Village_pump_(idea_lab) or Village_pump_(technical) - help desk is not so relevant IMO; because you're not asking for help, you're suggesting a technical change. Once you get some feedback there, you can make a formal proposal at Village_pump_(proposals) or a similar place (I know, we have a lot of similar places...). As for your proposal: I think adding slightly longer descriptions might work ok, but a complete description is hard to do with just words and very long. This is why we have worked examples in several WP:TUTORIALs. You might also enjoy the slightly silly but informative The_Wikipedia_Adventure. I like to learn by just looking at page sources to see how certain effects are achieved. You can work lots of fancy formatting and markup into articles, but you don't really need to if you just want to add refs or correct grammar, etc. For the desks, all you need to know is to put URLS in single square brackets like so  ->, and put wikilinks in double square brackets like so: google -> google. Lastly, as you learned, the standard ref tags don't work well on talk pages, but that's just one of those idiosyncrasies that you have to pick up through experience :) SemanticMantis (talk) 14:03, 27 January 2016 (UTC)

→ see Help:Formatting for a quick overview. In the article namespace, the German project which is the German version of Wikipedia uses "Wikilint", a spellcheck for nonscientifiy and improper usage of words and some advertising speach. -- Hans Haase (有问题吗) 12:36, 28 January 2016 (UTC)