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Tech 101

 
 
Phex: Dorset Doom
12:22 / 27.05.06
This is a thread, in the spirit of the various 101s appearing on this site lately, to help our community solve their technical problems, that is, anything relating to computing, electronics or mechanics. It's also a place to share tech related hints and tips and resources (like the wonderful Make Magazine).

To start us off there's a few technical questions that have been bugging me for a while:

1) Crashing: every time I play a game that uses 3D graphics in any way I can usually only play for 30 mintes tops before the screen freezes permanently and I have to restart my system (which, incidentally, has a AMD 2.4ghz processor, 512mb ram, 512mb ATI 9800xt graphics card and 530 watt PSU). What causes crashes? Is there anything I can use to diagnose the problem?

2) Networking: I have two systems, a desktop and a laptop, and I'd like them to be able to share files. Both can connect to the Internet through a wireless router, just not to each other no matter how I set up the 'Set up a home or small office network' thing. To make matters worse, the laptop has a broken Ethernet port, so hardwiring them together through Ethernet is out. Is there something I'm doing wrong and are there products available that will connect the two machines through USB or Firewire (though I'd prefer something wireless)?
 
 
ORA ORA ORA ORAAAA!!
13:13 / 27.05.06
Networking is often ridiculously complicated, so making it actually work from afar is more of a stab in the dark than anything else.

I'm going to assume your machines are using windows XP, because it's the odds-on favourite, but if they're not, or they're running two different operating systems, then, um, it might be harder.

So, I make no guarantees, but try this (sorry if I'm telling you things you've done before, too, you never know - oh, and as always, it's probably best to read through it before jumping in and doing it, and thinking about the possibly security implications and whether or not you've done all this before):
open up control panel, and if it's not in 'classic view', switch it to that. Then open up the network connections part of control panel.

find whichever connection you're using to get to the router and right click on it, bring up its properties. Make sure that, in the box you see labelled "this connection uses the following items" that there's a File and Print Sharing for Microsoft Networks item, and that the box next to it is checked.

(If there is not a File and Print Sharing item, and you have run the setup network wizard before, something more serious is wrong with both your computers, give up now! But there will be one, probably.)

Then, go to the advanced tab, and go into the Windows Firewall settings.

I'd suggest turning the whole thing off, because it makes everything a lot easier for you, but it may make everything a lot easier for everyone else, as well. You are unlikely to be the target of malicious malingering, but you never know.

I'm not sure if it's possible to actually network smoothly without turning it off. You should, in theory, have a firewall in your router, which is probably a better bet.

regardless, go to the advanced tab, and click the ICMP settings tab. Checking everything is once again not entirely necessary, but at least check the first one - it'll make things a whole lot easier (it'll let you ping and be pinged by other machines on the network, so you can see if you can, um, see them, at least in some sense, even if you can't steal their files). The rest of them you can probably deal without.

Then find your connection to the router in the box at the top of the window you're in (reminder, as it's easy to get lost: the firewall settings advanced tab), select it, and click settings.

Ignore the first tab. The second tab, this time, is another ICMP list, this time you should probably check them all.


Apply all this and leave back into control panel (this may require rebooting). Launch the system component, and in the computer name tab of that component, make sure both your machines are in the same workgroup (not vital, but again makes things easier).

Now find a directory, any directory, that you want to share. You can use the root directory, but the option to share it may be disabled. For testing purposes, make a directory called 'temp' and then right click it, open its property page. click the sharing tab.

Actually, at this point, I think if you have windows firewall turned on, you will be unable to share the folder. Go turn it off. I am pretty sure you will need to turn off WF to share the root directory, but even then you'll have to go through several prompts to do it, but the method is similar and should be fairly clear.

Otherwise, if you can, click 'share this folder on the network' and 'let other users change my files' (as I assume you want to move things between computers sometimes).
Give the folder a share name, and apply it.


In theory, now, you'll be able to see your machines on the network (in explorer, under 'my network places', 'entire network','microsoft windows network',then whatever workgroup you chose, and then, hopefully, the two computers you've put on ther), but you'll probably have to reboot at least eight times for this to work, because computers are completely random machines which only pretend to have orderly problems and functions.

Also, in all likelihood, this won't work at all and you will be even more frustrated, for which I apologise.

There are cabled networking possibilities with firewire and USB2, firewire is easier as windows is set up to recognise it as a networking medium, but I don't know how to go about it, exactly, and hopefully you will have worked everything out without needing to resort to that sort of thing.


Good luck!
Anything that doesn't work out, feel free to question my ability and demand answers, I'll see what I can do...
 
 
Bamba
13:27 / 27.05.06
Crashing: every time I play a game that uses 3D graphics in any way I can usually only play for 30 mintes tops before the screen freezes permanently and I have to restart my system (which, incidentally, has a AMD 2.4ghz processor, 512mb ram, 512mb ATI 9800xt graphics card and 530 watt PSU). What causes crashes? Is there anything I can use to diagnose the problem?

I'd guess an overheating issue here. If your machine's only locking up when you put it through it's paces then chances are it's a heat build up caused by the more demanding nature of playing games versus surfing the internet and the like which won't have your CPU or gfx card even breaking a sweat. Whether the it's the CPU or gfx card that's causing the problem though is hard to say but as a first pass at diagnosis I'd run something like Speedfan (http://www.almico.com/speedfan.php) and keep an eye on the temperatures it reports. Maybe run it for a while when you're just dicking around on the net to get an idea of what your system's idle temp is then play a game for 20 minutes before dropping back out and checking if there's a substantial increase. If you do notice a temp spike then you need to get more cooling in there, maybe add case fan or replace the fan on the CPU/gfx card. Actually the first thing to do is probalby to open the machine up and switch it on to verify visually that all the fan's are actually running, if one of them's failed then that's your culprit right there.
 
 
Shrug
13:29 / 27.05.06
What is a firewall? Software/Hardware? What specifically (in non-technocrati speak for the uber-luddite) does it do?
 
 
ORA ORA ORA ORAAAA!!
13:37 / 27.05.06
A firewall is generally software, though I imagine there are hardware versions for ISPs and so on. They can run on your computer, or your modem/router, or even on another computer which you get your data through, if you want.

It's basically a bouncer for your computer's network connections, which lets people/data packets on the guest list(so, anything from a specific machine or i.p. address you have allowed) and people who meet the dress code (packets on a specific port, for instance the ones used for getting data from internet pages) in, and keeps out all the undesirable riff-raff.

Except that it also keeps things inside, sometimes, too.

And they're a little more complicated than that.

But that's pretty much it.
 
 
Bamba
13:40 / 27.05.06
A firewall's basically like a barrier between a single machine (or network of machines) and the outside world. A firewall basically interrogates any connection that's attempted through it and decides whether to let that connection through depending on how it's been set up. Hardware and software firewalls work in slightly different ways but they both serve the same purpose of trying to secure the traffic that flows through them; allowing legit traffic and denying anything that's suspect.
 
 
Shrug
14:06 / 27.05.06
Good-good, thanks both, I had vague ideas about walls made of fire that had something to do with blocking pop-ups, virii* and limewire (on my college network) but that was about it.

*Although I did just use virii instead of viruses which is a bit l33t-ish, ah the jargon but so little know-how.
 
 
Phex: Dorset Doom
21:10 / 27.05.06
Thanks Bamba- that program showed that my CPU gets hot-hot-hot (+50 degrees, compared to the rest doing about 35-40) when it runs graphics-intensive applications (which should be handled by my GPU surely?). I'm in the middle of slowly upgrading my machine (in the end it'll have a AMD 4400 64, X800xt graphics, 1k of RAM and a little Hobbit that tells me how good I look) so I guess I'll wait until I have my new motherboard in before I get a new fan- and hold off on games. That is unless anybody has some clever trick to cool a CPU without spending any money?
 
 
Kiltartan Cross
23:27 / 27.05.06
Alas no, but I'd recommend Zalman as suppliers of good (and especially, quiet) fans and cases if you are spending money.

(edit)

Although you could try leaving the sides of the case off. If your case is like mine, a mongrel housing for mongrel components, then your CPU and graphics card will run slightly cooler, at the expense of providing you with an irritating whining noise. If your case is a sleek, modern, hyperdesigned piece of techonology, in which airflows have been calculated, a la Macintosh (spit!*), then taking the sides off will probably make it run hotter.

It's worth a try, though.

*Repeat after me, Apple. "The exchange rate is not £1 = $1. I will set my UK prices using the real exchange rate instead of my own made up fantasy Apple rate." I'd be tempted by some Apple kit (I have the opportunity to use it a lot) but their mode of pricing makes Macrosfot look like Mother Theresa.
 
 
■
23:35 / 27.05.06
Anyone who wants to know how security, firewalls and all that jazz works should subscribe to the Security Now podcast, which is just astonishingly good. Start at ep1 and work your way up.
 
 
Bamba
09:27 / 28.05.06
Thanks Bamba- that program showed that my CPU gets hot-hot-hot (+50 degrees, compared to the rest doing about 35-40) when it runs graphics-intensive applications (which should be handled by my GPU surely?).

Well most of the graphical wizardry will be delegated to the gfx card but the CPU will still be getting much more of a workout that when doing normal stuff like web-surfing so if it's badly cooled it'll still suffer. Aside from trying Kay's advice which is definitely worth a shot you could also stick a new fan on the CPU and make sure to use some good quality thermal paste while you're at it and that might bring the temperature down.
 
 
Red Concrete
09:44 / 28.05.06
I concur with the above. Be very careful with thermal paste, though if swapping the heatsink/fan. Poorly-applied thermal paste can cause overheating problems too...

You don't want a layer of paste - you want a skimmed sheen, barely enough to see, just enough make fill in any minute uneven-ness in the cpu-heatsink contact.
 
 
All Acting Regiment
10:57 / 28.05.06
Shrug, you might be able to allow limewire thru your firewall, if that's what you want. Are you using windows XP?
 
 
Bamba
11:05 / 28.05.06
If the college proxy server is indeed blocking LimeWire at that level then there's not a lot you can do, everything that gets in or out is at the mercy of the proxy you're going through basically and there's no way (that I know of) to override that from your end. LimeWire's a bit pish anyway, I'd take BitTorrent over anything else, although that too could be blocked I suppose. That said, with a decent BitTorrent client like uTorrent you can easily switch on encryption of the data packets which gets round a lot of traffic shaping which could well work in this situation.
 
  
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