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

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July 8

Installing Apache Tomcat for Eclipse on a Mac

Hi. I am currently trying to install Tomcat on my Mac using these instructions [1] but have quite quickly hit a stumbling block and need help. When executing the first line of step three, the shell returns to me the error message

The BASEDIR environment variable is not defined

This environment variable is needed to run this program

Then, when trying to execute the second line of step three, I see the output given on the webpage but also

Using CLASSPATH: /Users/Conor/apache-tomcat-6.0.37-src/bin/bootstrap.jar

touch: /Users/Conor/apache-tomcat-6.0.37-src/logs/catalina.out: No such file or directory

/Users/Conor/apache-tomcat-6.0.37-src/bin/catalina.sh: line 373: /Users/Conor/apache-tomcat-6.0.37-src/logs/catalina.out: No such file or directory

What do I need to do to make this work? I take it it's just a case of setting BASEDIR to the appropriate value (though I don't know what that value is) and creating the file catalina.out (thought I don't know where or what information it should contain by default). Thanks. meromorphic [talk to me] 11:47, 8 July 2013 (UTC)

This seems to be a fairly common problem for example see [2]. You might be able to just set use export BASEDIR=/Users/Conor/apache-tomcat-6.0.37-src. --Salix (talk): 12:24, 8 July 2013 (UTC)

why is memory so expensive in phones?

Why does Apple charge you $100 extra dollars if you want 32 gigs of space instead of 16 and $200 more if you want 64 gigs. What is so expensive about putting extra memory inside the phone?--Jerk of Thrones (talk) 17:46, 8 July 2013 (UTC)

Price discrimination Hcobb (talk) 17:51, 8 July 2013 (UTC)

I don't think that's shockingly expensive. I typed "price 32g dram" into Google and it seems to cost more than $200 at current rates, whereas "price 32g ssd" came up with things in the neighborhood of $100, but looked too big to stick in a phone. Are you maybe comparing against HDDs? That's not the right thing to compare; you can't really put an HDD in a phone. --Trovatore (talk) 17:57, 8 July 2013 (UTC)

The string to search for is "32gb sd". Which is well under $30 these days, if only Apple allowed SD cards to plug in... Hcobb (talk) 18:30, 8 July 2013 (UTC)

SD cards are slow. I don't know whether that's an issue for the phone in question or not. --Trovatore (talk) 18:38, 8 July 2013 (UTC)

Our OP asks why memory is expensive. The expensive part is making the whole thing work.

Nobody stops you from building a silicon fab in your back yard, designing your own digital logic to implement nonvolatile memory; worrying about all the troubles of electronic design automation and design for manufacturability; supplying high-quality silicon wafers that are not full of defects; acquiring the necessary photolithography machinery; spinning the photoresist, etching the wafers, dicing the wafers, packaging the wafers, gluing them to the phone in a way that does not break, snap, crack, or otherwise fail in any condition; making sure that the electronic connectivity is all working correctly...

...and of course, market pressure dictates that you must do all these things at a cost lower than anyone else who could supply an equivalent product.

But, despite much very uninformed propaganda designed with very nice bold-face fonts angrily declaring that this stuff ought to be easy for some reason, almost nobody wants to expend this sort of effort. Instead, most consumers willingly pay someone else to do it, and because there is a healthy market demand, the final retail supplier can charge $100, more or less, for 32 GB of memory. Nimur (talk) 19:06, 8 July 2013 (UTC)

Actually I expect a good class 10 microSD card is faster than the flash memory in the iPhone or at least the same (let alone a UHS class I) and you can buy one for under US$30 retail. To be fair, some of these probably have rather poor small file performance which you likely don't want in a phone, but not all and I think that's usually more related to the controller than the flash chip. Remember SD and to a lesser extent microSD (but the standards are basically the same) are used in devices far more demanding of speed, like some cameras and video cameras, than the iPhone or any phone.

In any case it's a moot point, SSDs cost under $1 per GB retail in the most bang per buck capacities which I think is currently around the 250GB mark. (A 32 GB SSD will probably cost more for various reasons in retail channels including the fact it's too small to be considered useful for anything but a cache drive but you should be able to buy one for under US$50. There may be reasons to pay slightly more depending on what you want from your drive but if you're paying $100 in the US for such a drive, I strongly expect you're paying way too much.) These are definitely faster than the flash memory in the iPhone (and while the sizes I'm referring to are obviously bigger and may use more chips and may use SLC rather than MLC, they also have more capacity, the size is as much about form factors and the faster speeds expected as anything).

I don't get why you are comparing the price of DRAM when the OP was clearly referring to flash memory in the question even if the title was unclear. The iPhone 5 only has 1GB of RAM whichever model you buy. And while there is surely some correlation between the prices of flash memory and DRAM since they're both part of related industries with similar manufacturers, the DRAM industry seems a bit insane with frequent lows due to gluts followed by manufacturers all cutting production to increase prices. I actually expect there's more correlation between HDD prices and flash memory since they still compete to some extent in the SSD market. It's a moot point though since HDDs are still far cheaper per GB while flash has cheaper per GB for a while now according to our SSD article it was in 2004 so it's little use taking in to account either.

Nil Einne (talk) 21:56, 8 July 2013 (UTC)

Trovatore, comparing DRAM to flash memory is a giant red herring distraction from the original question. You must know that comparison is shockingly misleading. As for the reason, it's simple price discrimination. If there was a product out there identical in every way to the current iphone, but one charged $30 and one charged $100 more for the extra storage, it's obvious. But there's not an identical one, so Apple maintains pricing power. Shadowjams (talk) 01:06, 9 July 2013 (UTC)

Well, whatever — I don't have a smartphone, never liked the idea much (I like large, convenient user interfaces for computing, and small, easily pocketable telephones), so I didn't know what sort of memory was being discussed. I'm not particularly a fan of Apple, their closed ecosystem and non-DYI-friendly attitude being prime reasons; I just didn't think this particular comparison was especially outrageous. --Trovatore (talk) 02:48, 9 July 2013 (UTC)

Whatever whatever. You don't need to be an apple fanboy to recognize that volatile memory is quite different from flash memory. Either you are much more ignorant than I expected given your history here, or you're being misleading in your comparison. Your concerns about Apple's closed infrastructure are quite valid, but I'm not sure why that requires the responses you've given here. Shadowjams (talk) 05:26, 9 July 2013 (UTC)

You're not making any sense, SJ. My response on the memory was if anything pro-Apple, in spite of my predilections; I was saying I didn't see their behavior as particularly out of line, at least this one time.

Of course I know volatile memory is different from flash memory, but I didn't know which kind the OP was comparing -- my bad, I suppose I could have figured it out if I'd wanted to go to the trouble. What I don't understand is why this upsets you so much. --Trovatore (talk) 07:56, 9 July 2013 (UTC)

Desktop remains black except task bar and mouse pointer

Hello there. Yesterday evening, I suddenly encountered this irritating problem. I don't know what exactly caused this problem. When I start my desktop (Windows 7, 64 bit), it appears completely black except the task bar which contains only start menu icon. Other icons in task bar don't show up at all. I can move my mouse pointer anywhere, but when I move mouse pointer on task bar it shows that it is processing something (I mean a "O" circling). I tried bringing task manager by pressing ctrl+alt+del, but even it did not show up at all. All I have to do is, reboot the system and run it either "Safe mode" or "Safe mode with networking". I can't run any software or applications that requires high graphic intensity (I am not talking about video game). Even I can't run office 2010, let alone video and audio. I checked the hardware but all seems working fine. My specs are:

• Core 2 Quade 9400
• Nvidia Geforce 9800 GT
• Ram 4 GB
• Motherboard Gigabyte UD3L
• Thermaltake power supply (750 watt)

What's the problem? What am I missing here? I shall be grateful if anyone help me out on this regard. Thanks in advance.--180.234.228.132 (talk) 19:38, 8 July 2013 (UTC)

Sure sounds like malware to me. If you have an antivirus program I would suggest you run a scan with it; and if not, then you should definitely get one (popular free ones include AVG, Avast!, and Ad Aware.) The malicious program is probably blocking task manager from appearing so you can't terminate it's processes. --Yellow1996 (talk) 00:52, 9 July 2013 (UTC)

Another possibility is that it's some piece of software which loads at boot time, and is caught in an infinite loop. Did you add any software or do any downloads/upgrades recently ? If so, you might want to disable those apps. StuRat (talk) 06:27, 9 July 2013 (UTC)

I have the same or similar occasionally happening with windows 7.x and Safari. The only solution has been close and reopen, sometimes after reboot too--but I cannot say reboot's necessary. μηδείς (talk) 06:30, 9 July 2013 (UTC)

Well, I partially solved the problems. Some loopholes still persist. So what I did is:

• I have Malwarebyte antimalware pro and Norton internet security. There is no Malware found in my system. NIS only detected two tracking cookies which have been successfully removed from the system.

• I still had that nagging problem, so I suspected it is related to my Graphics card. I then updated driver from Nvidia website. But alas! whenever I tried to install the driver it says, "Nvidia Installer failed". Hence, I disabled display driver from device manager, restarted PC and able to run a clean installation. I used driver cleaner pro to clean any leftover before clean installation.

• This evening, when I started my PC, it took longer than usual time to load system. I restarted it again see what's going on. And again that "black screen with mouse pointer and taskber appears". I shut down the PC and started it up again (as usual it takes longer than usual time to load the system) and it seemed to Okay. I mean desktop appears normally. But each time I shut down and restart system, this problem appears and then disappears. It still persists. I have not downloaded/upgraded software recently. Everything seems Okay and then problem comes back. I don't know what causing this problem. What to do?--180.234.23.166 (talk) 17:29, 9 July 2013 (UTC)

Trying doing a System Restore, which winds the computer back to an earlier time. You can get to this via the start menu, actual location vary with windows version. It will let you choose a time you want to restore to, choose one before you had problems and start it running. This can fix a lot of messed up software problems.--Salix (talk): 20:13, 9 July 2013 (UTC)

• I could have easily restored the system if I knew the exact time when this problem started. Changes in registry or unexpected removal of them cannot be undone by system restore. It's obsolete now. I have disabled malwarebyte Pro from system startup and it seems work fine. But I am not sure whether it solves this nagging problem. Still experiencing longer loading time in system startup.--180.234.62.200 (talk) 14:21, 10 July 2013 (UTC)

Android Tablet Help

I have a Samsung Galaxy Tab 2 7.0, and I have the option of making a folder on one of the screens. This would be handy, but I can't seem to find out how to put anything in it. I have 6 files, downloaded from email I sent to a client, and would like those files sitting in the folder I made. However, when I go to the 'Download' folder, the only options I have are to either share by various means or to delete them. Is there any way I can get them into this folder? I really would like to have them there. KägeTorä - (影虎) (TALK) 21:41, 8 July 2013 (UTC)

Some intense Googling and I turned up this page (among many others); and it looks as though folders are only meant for app shortcuts, not your own files... --Yellow1996 (talk) 01:07, 9 July 2013 (UTC)

For some reason I have never been able to fathom Google doesn't consider working with files and folders in this way a core feature of android, so the only way to do this is using a third party app such as ES file explorer (this is just the one I use, there are many file managers available for android). This has the ability to add shortcutsto the android home screens by long pressing on the file/folder and selecting "more" then "add to desktop". Equisetum (talk | contributions) 14:33, 9 July 2013 (UTC)