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Wikipedia:Reference desk/Archives/Computing/2011 October 26

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October 26

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Digital camera market: all-in one with excellent macro and remote shutter triggers

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Hi, I digitally photograph documents, large sequences of documents, to produce research aids. While there are many good light digital cameras, making for easy tripod management; and, there are many light digital cameras with good macro; I've had difficulty finding non SLR cameras with remote shutter triggers. Ideally a foot trigger, or a hand trigger on a long wire or wireless would be ideal. I've reached a point where the ergonomics of pressing the shutter trigger on the camera for six to seven hours a day is a serious negative impact.

The reason for a light camera relates to non-standard page formats in the document series, for which dismounting the camera rapidly and taking a photograph while holding the camera is the best workflow solution.

Do users have any advice on seeking such a camera? Fifelfoo (talk) 00:05, 26 October 2011 (UTC)[reply]

Would a solution involving two cameras be acceptable? That is, could you use a tripod-mounted SLR with an appropriate remote trigger for the majority of documents, and a handheld point and shoot for the handful of non-standard-sized pages?
Alternatively, are you willing to do a bit of mild hacking? Firmware modifications like CHDK allow you to use the USB connector on Canon Powershot point-and-shoot cameras to connect a remote shutter release to a whole family of cameras that wouldn't normally support them. This includes some high-end point and shoots like the S95. TenOfAllTrades(talk) 01:36, 26 October 2011 (UTC)[reply]
CHDK is also programmable in a BASIC dialect. You could use the supplied time-lapse script to take a picture every N seconds, where N is the number of seconds you need to turn the page. With more work, you could modify the motion-triggered script to take photos after the motion (page turning) stops, instead of during the motion. -- BenRG (talk) 04:22, 26 October 2011 (UTC)[reply]

Thanks for the grounding advice. The workflow passes from meters of archives, with box numbers, through the camera, towards sequence managed files. A two camera solution has problems in that the date-time would need to replace file number identification in terms of maintaining image sequence... but this is not insurmountable (thanks for the idea!). The workflow gets reassessed about every five years (ie: when I need a new camera / get funding for the same), so hacking _could_ pay off, N second timing would be one way forward, particularly if it could be turned on or off; one problem is that in the workflow the user gets interested in documents, and pays more or less attention to particular pages. CHDK looks like an excellent central component of a hack to solve this, regardless of an external line or a timer being the right way forward. Good on Canon for being "open," or tolerating openness, about their firmware's programmability. Fifelfoo (talk) 06:56, 26 October 2011 (UTC)[reply]

Some companies sell cheap substitutes for dedicated remote shutter releases where you clamp a bracket around the camera which goes over the shutter release, and then a remote switch causes the shutter release to be pressed. If you look on eBay or similar you may find something suitable, or there are online guides on building your own. Although this may not be reliable for extended use. --Colapeninsula (talk) 13:22, 26 October 2011 (UTC)[reply]

Who defines partition types and GUIDs?

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Who defines the partition types used in the Master Boot Record partition table and the GUIDs used in the GUID Partition Table? Related question: What happens if someone wants to make a new partition type? Companioncube31 (talk) 02:45, 26 October 2011 (UTC)[reply]

I don't know what registries exist(ed), but GUIDs were designed so that there needn't be a central registry to prevent collisions, and the large number of collisions in this table indicates that a lot of vendors didn't bother to register their 8-bit type codes, even if an official registry did exist. -- BenRG (talk) 04:53, 26 October 2011 (UTC)[reply]

Computers and lightning

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When there is a thunderstorm, does one have to unplug the PC, modem, etc. even when the storm is several miles away? I always do, but my son insists that lightning can only cause damage to the modem and PC whilst the storm is directly overhead. Thank you.--Jeanne Boleyn (talk) 07:02, 26 October 2011 (UTC)[reply]

This really depends on how the power grid near you is set up. A lightning strike would only cause damage if it hit the distribution line between you and the nearest substation. Most of these distribution lines have some kind of surge protection on them nowadays. This isn't to say there isn't still some risk involved, particularly in rural areas, and I personally tend to at least unplug the phone lines (which are often not so well protected- though less likely to actually be struck, given their lower positions) in major storms around this time of year. Nevard (talk) 08:12, 26 October 2011 (UTC)[reply]
You can take your time unplugging the equipment when the storm is several miles away, or you can madly scramble to do so when the storm is overhead. I'd choose the former. --LarryMac | Talk 13:15, 26 October 2011 (UTC)[reply]
There are some surge protectors that also claim to offer US$10,000 (or whatever) of insurance on electrical equipment, like computers, that suffer surge damage while hooked up to the surge protector. Boom, new computer! I'm not sure of the details, of course, and am not even sure whether these insurance policies tend to exclude lightning strikes from the coverage. Comet Tuttle (talk) 01:10, 27 October 2011 (UTC)[reply]

Day-by-day financial program

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I'm looking for a program that allows one to track future expenses day by day. Say, like having it add $XXXX.XX dollars every Friday (payday), and having it deduct $YY.YY every day (say, lunch) and $ZZ.ZZ every month (recurring bills, etc.) Basically, something that I can put all my income and expenses into, and be able to see roughly my balances on any given future date. Does anyone have any suggestions? Avicennasis @ 09:08, 28 Tishrei 5772 / 09:08, 26 October 2011 (UTC)[reply]

I use an Excel spreadsheet to do something like this. Leftmost column is the date, starting with (at A2) =TODAY() (but you could use a fixed date) at the top, then going down each row is the next day, eg A3 is =+A2+1. I have one column for each regular incoming/outgoing, eg for weekly (Friday) pay =(WEEKDAY($A3)=6)*9999999 (real amounts are redacted!), for fortnightly income =(MOD(A3-DATE(2011,9,26),14)=0)*999999 where the date is any arbitrary past date on which I received the income, =(DAY($A3)=15)*999999 is once a month (15th in this case). (In case it's not obvious, boolean functions return 1, 0 for true, false, so (X=Y)*Z is the same as IF(X=Y,Z,0).) An extra column for manual entries. Then a column on the right to add them all up, with +same column, previous row for an ongoing balance. MIN() of the balance column ensures that it stays above zero! Simple, and it works for me. Mitch Ames (talk) 12:10, 26 October 2011 (UTC)[reply]

Android Market

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How do I 'associate' an android tablet with my Google account? Everytime I try to download an app from the market, I am told I do not have any phones/devices associated with the account. --KägeTorä - (影虎) (TALK) 12:38, 26 October 2011 (UTC)[reply]


What tablet is it? what happens when you try and do it from the device (I'm guessing you are using the web interface?) --Cameron Scott (talk) 12:43, 26 October 2011 (UTC)[reply]

It's an Archos 101, and this is the only device I am using, and yes, from the browser. --KägeTorä - (影虎) (TALK) 13:04, 26 October 2011 (UTC)[reply]
for some reason, Android market will not identify some devices, you should still be able to load them via the market place app on the device (you have a market place app right?). --Cameron Scott (talk) 13:06, 26 October 2011 (UTC)[reply]

Open your settings panel, go to Accounts & Sync, and add your google account. Then when you log into the website the tablet will be associated with that account. Just to make sure, download something from the android marketplace on your device (If the marketplace isn't on your homescreen click the Apps button at the top and find it there. 192.84.79.2 (talk) 14:00, 26 October 2011 (UTC)[reply]

PSU for multi-monitor setup

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I'm planning to buy an AMD Radeon 6850 graphics card, and a 500-watt PSU is recommended for this. The computer is a dual-core Athlon II with a Corsair CX400 PSU. If the card is used to run a multi-monitor setup, and 3-D rendering is not used, will this PSU suffice? --Masatran (talk) 13:31, 26 October 2011 (UTC)[reply]

I run two nVidia cards, each suggesting 500W power in the manual, on a single 550W power supply. I do not do any gaming or 3D of any kind (I only have these cards because they have multi-monitor output). I have not had any issues. -- kainaw 13:37, 26 October 2011 (UTC)[reply]

Multi monitor will make a tiny difference to power consumed since the monitors are powered from the mains. Your 500w PSU will work just fine, assuming it is actually a 500w PSU. 192.84.79.2 (talk) 13:57, 26 October 2011 (UTC)[reply]

  1. I'm concerned about the power draw, not of the monitors, but of the graphics card
  2. The PSU I mentioned is a 400-watt one.
--Masatran (talk) 14:37, 26 October 2011 (UTC)[reply]
At a guess the PSU should be able to handle the system although I'm not making any guarantees. The 6850 only has a single 6 pin PCI express connector so shouldn't draw more than 150W in total. [1] shows a higher end system (with Intel but probably still consuming more power) with a 6850 using 278W total (and that's at the plug so is more then the actual system is using) although only the GPU was stressed and it's not clear to me what they used to stress it anyway. I'm presuming you're referring to a quality 400W PSU, the Corsair CX400 sounds like it should be but you may want to check and also keep an eye on the +12V. From my experience most manufacturer power supply recommendations are higher then need be probably partially because they want to rule out the possibility of problems and there a lot of crap PSUs out there. If you have a wall power meter you can try measuring the system under load at the moment and guess how much headroom you have. Although in truth if you're not planning to game or do any other sort of 3D rendering I'm a but confused why you want such a high end card. If you're planning to use it for GPGPU bear in mind this could potentially stress the card as much as 3D rendering (after all that must be partially the point of such a high end card). Even if you want 3 monitors (pretty much all stand alone cards for a long time have supported dual monitors), I'm resonably sure most of the lower end AMD/ATI cards have EyeFinity as well.
Edit: [2] this one is using Furmark shows 253W and 246W and again it's the power measured at the wall and a higher end system, [3] is also using Furmark (although it also has Crysis which is lower) and shows 274 and 292 although the system and measurement method is uncertain and again it doesn't seem like the CPU was stressed (well it would be in Crysis to some extent), [4] shows 284W although the measurement method doesn't seem to be specified and it's using Crysis (as hinted at earlier although this may stress the GPU less it means the CPU is also stressed to some extent) and again with a higher end system, [5] shows 273W at the wall with Left 4 Dead 2 again with a significantly higher end system. From these I'm even more confident you'll be fine presuming the +12V isn't an issue (although even that is looking unlikely to me).
BTW for clarity Furmark is pretty much the gold standard for GPU power consumption and temperature, it's able to stress cards so much that drivers for certain cards detect it and reduce the card speed. In other words, it's the sort of thing that manufacturers are saying can stress cards beyond design specs. (From what I've read the reason given is about power consumption or fear of stressing certain components particularly the VRMs beyond design limits, most cards also have thermal throttling since a long time. In the past it was a simple application detection and just renaming the exe was enough to prevent this behaviour as I can confirm from experience, but now some are using more advanced management methods [6] [7].)
Nil Einne (talk) 17:00, 26 October 2011 (UTC)[reply]

120 bang for the buck

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http://www.techmtaa.com/2011/10/04/kaboo-is-this-the-first-kenyan-designed-tablet-computer/

 CPU: VIA WM8650 (800MHz 300MHz DSP)
   Operating System: AndroidAndroid 2.2
   Screen: 7-inch resistive touch screen
   Storage: 256MB DDR2 RAM and 2GB internal storage
   3G : Supports external 3G (USB 3G) Modem
   Card Reader: Supports High-speed Micro-SD card (maximum: 32GB)
   SoundSound reviews: Built-in speaker, Built-in micphone
   CameraCamera reviews: 0.3M Pixels Web Camera
   Orientation Sensor Automatic steering display screen
   Supports Wi-Fi 802.11 b/g
   Supports adobe flash 10.1
   HighHigh reviews-sensitivity G-sensor embedded


Is this product any good? It's cheaper than an ipad way cheaper. What are its cons. I'm looking for a good tablet. — Preceding unsigned comment added by 62.24.111.249 (talk) 13:34, 26 October 2011 (UTC)[reply]

It's running an old version of the android OS, it's got a resistive touch screen (As opposed to the multitouch capacitive touch screens modern devices have), it has hardly any ram, a tiny webcam, and is probably pretty slow. edit: Compare Capacitive Touchscreen and Resistive Touchscreen192.84.79.2 (talk) 13:52, 26 October 2011 (UTC)[reply]

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for locally hosted files? tried localhost, file, 127.0.0.1, c, all do not work. all punctuation is truncated. using firefox 3.x on an office computer, cannot upgrade. — Preceding unsigned comment added by 218.186.17.226 (talk) 14:34, 26 October 2011 (UTC)[reply]

If you have a locally running HTTP server and are using an http:// url, localhost or 127.0.0.1 should do it. If you're using a file:// url, you might be out of luck. 130.76.64.119 (talk) 15:26, 26 October 2011 (UTC)[reply]

jt open toolkit

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why is there not a differentiation between http://en.wikipedia.org/wiki/JT_%28visualization_format%29#JT_Open_Toolkit and the IBM i5OS java toolkit open source project (JTOpen) at http://www-03.ibm.com/systems/i/software/toolbox/index.html, and on sourceforge???

) — Preceding unsigned comment added by Wessonjoe (talkcontribs) 17:02, 26 October 2011 (UTC)[reply]

Amiga emulation

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Now that I have a full copy of my Amiga's hard drive on my Linux PC, I started wanting to actually use all those applications and games. I do have a real, physical Amiga 4000 on my desk right now, but I'm not sure if it works OK any more, and it's a bit of a hassle to use two computers instead of one. So I would be interested in emulating the Amiga on my Linux PC. What sort of Amiga emulators exist for Linux? Surely they're able to read files on the host Linux filesystem? Do I need to somehow transfer the Kickstart ROM from the real Amiga to the emulator? If so, how can I do this? JIP | Talk 20:13, 26 October 2011 (UTC)[reply]

Take a look at these Amiga emulators for Linux

TheGrimme (talk) 21:19, 26 October 2011 (UTC)[reply]

OK, I took a look at the links and downloaded the source code for both UAE and XFellow. I couldn't get either to even compile. UAE didn't compile because of a problem with GTK+, and I wasn't able to get XFellow even past the "./configure" stage, because I didn't even find the "configure" script. But then I found that my Fedora 12 Linux installation already included E-UAE, so I started it.

First it complained that it had no Kickstart ROM. Then I remembered that I had already bought the Amiga Forever CD-ROM, so I copied its contents to my Linux system and used the Kickstart 3.1 ROM, as my real Amiga has Kickstart 3.1. I set UAE to emulate a 68060 CPU, which my real Amiga has. When I started it, I got a message "Invalid 68040.library!" So I switched it to emulate a 68020 CPU instead, which is inferior to my real Amiga's CPU. Then it started up and loaded Workbench, but the screen was all messed up. It turns out that my real Amiga has a Multiscan monitor and is thus able to use the DBLPAL screen mode, but UAE doesn't know how to emulate this. So I loaded up the ScreenMode preferences and switched to PAL Super-HiRes Laced instead. On a real Amiga, this would have flickered irritably, but current flat-panel computer monitors don't have this problem, so I was able to see the display all OK.

When I got Workbench working, I tried to play some of my installed commercial games - Benefactor and Ork. WHDLoad worked perfectly under emulation, but then I found that although the graphics worked perfectly, the sound was messed up. It played correctly, but with a horrendous lag that caused it to play so slowly that it had trouble keeping up with the notes, and missed some notes. So now I have an almost perfectly working emulated Amiga. But what can I do about the sound? JIP | Talk 18:22, 27 October 2011 (UTC)[reply]

It looks like [8] you want to fiddle with the sound_latency value in the config file. Update: having said that, I've been trying to run a game in WinUAE, and can't fix the sound - at low latency values it's crackly, at high latency values it's choppy. This thread [9] says that an unreasonably powerful PC is needed to make the sound emulation work properly. "Am I the only person that finds it incredibly amusing that you need a 2,000 + mhz windows computer to properly emulate an 8mhz amiga?" says the poster, and somebody else comes up with a pat justification. I'm not too impressed. To paraphrase Apple's motto, "It just doesn't work". (And the sound on games on my Linux PC suffers from similar problems - due to there being a mess of different sound libraries which games don't support - even without running UAE on it, so I dread to think of the problems caused by combining the two.)  Card Zero  (talk) 23:11, 27 October 2011 (UTC)[reply]
Looking at it briefly, the Paula's audio function doesn't look that hard to emulate on modern hardware; it's mostly a digital sample shoveler, like almost all modern audio interfaces. On the face of it that would make it much easier to emulate than a chip like SID or the EMU8000, which have extensive analog-side synthesis, modulation, and filtering (all of which require the emulator to do DSP for each element of the emulated analog circuit). The Paula seems to have only a single simple filter, processing for which isn't that hard. And SID is emulated very well by lots of systems. The only thing of note is that it appears the Paula emits samples at some rather unusual rates (e.g. 28867Hz). It's the job of a modern sound server like WASAPI or PulseAudio to take sample streams emitted by different clients at different sample rates and mix them altogether into a single sample stream (at whatever rate/width they've configured the actual audio hardware for). Audio servers usually have optimised plugins for common conversions (e.g 16384Hz -> 44.1kHz) with hand-tooled optimisations for the resampler; given a conversion they don't know how to do (and if they're seeing weird sample rates from the emulated Paula, which is keeping in time with the emulated video) they'll fall back on a general resampling engine, which can be considerably slower. PulseAudio, in a addition, has several different resampling engines - the highest quality ones are the slowest. In the worst case you can suspend PulseAudio (or JACK) and run the emulator straight on the ALSA hardware interface (but even the, if it's emitting samples at a rate the hardware doesn't know about, it must either resample or slur). -- Finlay McWalterTalk 15:34, 28 October 2011 (UTC)[reply]
I have no idea about the internal workings of Paula, SID, or modern audio drivers. How can I choose which audio interface UAE uses? There doesn't seem to be any such option in the UAE configuration file. I tried playing Stargoose, and the music was nearly faithful, but not entirely so. On the other hand, Utopia: The Creation of a Nation and Ork had severe problems with the music. Is the problem because my Linux PC's CPU is not fast enough? It's already over 2 GHz. Or would a dedicated sound card help? Currently I only have a sound card integrated to the motherboard. JIP | Talk 19:51, 28 October 2011 (UTC)[reply]
I don't know if it helps, but I did notice that there's a driver for AHI (Amiga) available, [10] which works with UAE (UAE is listed as a "soundcard" on that page). It comes with WinUAE in a directory called "programs", but isn't pre-installed, and I can't figure out how to install things so I don't know whether it solves the problem of the sound or not.  Card Zero  (talk) 18:10, 29 October 2011 (UTC)[reply]
No, that doesn't seem to help. I installed AHI and the UAE driver on the emulated Amiga, and the AHI preferences opens OK, but when I select the UAE device and click on "Play Test Sound", no sound is played. JIP | Talk 11:18, 30 October 2011 (UTC)[reply]

comverting FROM ePub?

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Hi - I have an ePub document I need to send to someone whose machine can't read that sort of file, and he's doing me a favour, so I can't implore him just to download the necessary software; I'd like to convert it back to PDF or Word, something like that - is there any way of doing this? Thanks Adambrowne666 (talk) 21:07, 26 October 2011 (UTC)[reply]

calibre (software) -- Finlay McWalterTalk 21:12, 26 October 2011 (UTC)[reply]
You can do it online here for free: http://www.epub-to-pdf.com/ TheGrimme (talk) 21:21, 26 October 2011 (UTC)[reply]
Thanks heaps, both of you - I might download Calibre another time, but for the nonce, the online converter worked a treat 22:52, 26 October 2011 (UTC)