Wikipedia:Reference desk/Archives/Computing/2011 December 30

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December 30

follow up: my pc swaps always on the hd

but is it normal that the HDD led is always on, even if I'm simply browsing the web? thanx --192.35.17.16 (talk) 10:51, 30 December 2011 (UTC)

Yes. Lots of reading and writing happens anyway, like updating cookies. StuRat (talk) 21:56, 30 December 2011 (UTC)

Transistor_count Article - Transistor count for Mux 4 input is 24?

Hello, I see that in the article – Transistor_count, Transistor count for Mux 4 input is 24. I guess we are referring to the Mux built using basic Gates (AND / OR Logic). I am not able to figure out the circuit being referred here. The link leads to a circuit which would consume more transistors then 24. Can you please help me to get hold of the circuit for 4 input Mux with the transistor count to be 24?

Thanks, Bukka — Preceding unsigned comment added by Bukka4 (talk • contribs) 11:11, 30 December 2011 (UTC)

For others' reference, the relevant articles mentioned in the question are transistor count and Multiplexer#Digital multiplexers -- Finlay McWalterჷTalk 11:46, 30 December 2011 (UTC)

My basic digital design textbook, Digital Design Principles and Practices, by John F. Wakerly, shows a two-element mux with six transistors. (Two AND, a NOT, and an OR). So, we could cascade two of those into a third, and use a fourth mux to switch the selector signal for the second-tier mux... and we get a four-input mux with 24 transistors (built from four individual 2-input muxes).

I suspect this is suboptimal; we could probably reduce the circuit complexity below 24 transistors. But, throw in some level buffers and a few transistors to regulate the current, and I could see getting up to 24 transistors in an actual, synthesizable design. On the other hand, it seems more plausible that an actual, synthesizable silicon chip would exclusively use NOR logic or NAND logic; so if you wanted to work within that constraint, you'd have to build the truth-table and figure out how to build it with those gates. And, you would probably want to investigate the actual fab process to see what transistor-level implementation is used for each type of logic-gate. In a very modern chip fab process, a mux is a primitive-element, and the actual circuit layout would be selected from a library of available mask designs, based on constraints from an optimizing logic synthesizer program.

The point is, it is theoretically possible to build a 4-input mux using fewer than 24 individual transistors (... I think); it is certainly possible to use more; so whichever article told you that it requires "24" was either incorrect, or was referring to some unspecified incarnation of a MUX. Nimur (talk) 17:30, 30 December 2011 (UTC)

The 24 comes from Transistor count#Logic Functions which (rather fuzzily) says "Transistor count for generic logic functions is based on CMOS implementation" (but provides no reference). I don't know what that's supposed to mean: whether they're asserting that 24 is typical, minimal, or what. -- Finlay McWalterჷTalk 19:13, 30 December 2011 (UTC)

blender 3D modeling software

Resolved

I recently downloaded the above program, and after a few minutes failing to get anything to work, managed to find tutorials online, including one that gives a detailed step by step guide to creating a 'gingerbread man' figure. It was going so well to start with, but then my computer turned itself off, (some other unrelated bug I am working on fixing) and I had to start again. Now, for some reason the program is doing different things to it was before, even though I am following the instructions carefully and have reset the program's default settings, just in case something had changed there. So, I am wondering, is there anywhere I can go to ask for advice on this from people that know the program, all I can find on their website is more tutorials.

79.66.109.0 (talk) 11:17, 30 December 2011 (UTC)

Try the forums in the "support" section here. -- Finlay McWalterჷTalk 11:51, 30 December 2011 (UTC)

I would just note also that Blender is a tough program to use — very unintuitive compared to any other programs you're used to, because the interface is very cobbled-together and unique — and there might not be an easy answer to what you're asking about. When I started using it, I was constantly making it do things that seemed unreproducible, likely because I had clicked one of its million tiny buttons without realizing it, or had pressed the wrong button on the keyboard without realizing it, and found myself constantly stuck, etc. But if you persist at it you learn to be quite disciplined about what you do, what you don't hit, how to (mostly) get out of situations you've created for yourself. It's a cool program in the sense that it produces some nice looking stuff without an excess of hardware or talent, but it's easily the most frustrating user-interface experience I've ever had with any program, ever. (Your warning that this will be the case comes from the fact that die-hard Blender users all say that they wish all programs had interfaces like this. Translation: I spent years learning how to use this damned program's interface, and those skills are totally wasted on anything else!) --Mr.98 (talk) 13:43, 30 December 2011 (UTC)

I have actually been finding it reasonably easy, compared to many other programs I have tried, it all seems to make sense and the guides and tutorials are easy to read and understand. Maybe I just think in the same way as whoever designed this. Anyway, the problem seems to have fixed itself somehow, so thanks for everything, might be helpful next time something goes wrong. 79.66.109.0 (talk) 14:56, 30 December 2011 (UTC)

I consider myself a bottom-rung advanced-level modeler (I can make a game-compliant fully unwrapped and textured gingerbread man in a few minutes, heh), I have handled different 3d programs usually for export/import compatibility reasons, and I have to echo Mr.98's sentiments above. Blender is the most alien of any 3d programs I have ever worked with. Compared to say, Maya, where skills can easily be carried over to other programs like 3ds Max, Modo, or Cinema4d with relatively minor differences; Blender's interface is an island and not in a good way. Be prepared to find yourself having trouble adapting to other software if you go with Blender as your native program. Admittedly though, of all open-source 3d programs, Blender is the most fully-documented with a lot of tutorials and a large user base (though you can say the same for more mainstream commercial 3d programs).

Anyway, I suggest finding out if they have IRC channels or somesuch, which would make it easier for you to directly talk with more experienced users. Open-source projects usually have those. -- Obsidi♠n Soul 15:16, 30 December 2011 (UTC)

How safe is being without antivirus software while downloading antivirus software?

McAfee insists that I uninstall Norton Antivirus before downloading their protection, which seems ridiculous. It seems that the software should be downloaded and then just not activated, after which you would uninstall the old antivirus software. I don't think I would have taken such a chance if I had known I'd still be sitting here watching the software download after two hours. I decided Wikipedia was probably safe enough to use given its lack of ads, since I didn't want to just go off and leave my computer knowing I have to be ready to act when the download is complete. As to why I'm doing this, it's cheaper and I can pay for Internet access, phone and security all at once instead of making a separate payment on a credit card I never use. And please don't tell me about free stuff as I'm afraid to trust that.Vchimpanzee · talk · contributions · 21:11, 30 December 2011 (UTC)

If you're that paranoid switch to something like Linux Mint Operating System. Not only is it free but it is also (by actuality) cheaper the the that antiviral software -too boot.--Aspro (talk) 21:29, 30 December 2011 (UTC)

You can then load-down tons of free software without viruses, trojans and other nasties.--Aspro (talk) 21:33, 30 December 2011 (UTC)

Be aware that Linux is completely different than anything you are used to using on Windows. Given the OP's past difficulties with plain old vanilla Windows, I don't want to be responsible for getting him up and running with Linux... I'm pretty computer savvy and I find Linux unbelievably frustrating when I've had to use it. --Mr.98 (talk) 23:10, 30 December 2011 (UTC)

Different, anyways. Completely different... not really. ¦ Reisio (talk) 01:12, 31 December 2011 (UTC)

Yes Linux is Not Window. If you try to stay with Microsoft's own version of operating systems, that only allows one to do what Microsoft allows you to do with a computer that you own then that's up to you. Is it not better to start-a-fresh and save yourself a lot of hassle in the future (editing registers, installing anti-viruses apps, and mind-boggling update, etc.) by learning a transparent and proper OS? If people had their first experience on Linux/Unix etc., then they would never bother to suss out the convolutions that Microsoft forces them though. Granted, one has to leave the Microsoft mindset behind to adopt something more flexible that doesn't constantly need tweaking and maintenance - but isn't that the whole point? --Aspro (talk) 23:50, 30 December 2011 (UTC)

That's all well and good, but doesn't answer the OPs question. It's like saying "buy a car" to someone who asks about a broken bicycle. 82.45.62.107 (talk) 00:44, 31 December 2011 (UTC)

Except in this case the car is free and the bicycle is massively expensive. :) But we digress... ¦ Reisio (talk) 01:12, 31 December 2011 (UTC)

Two antivirus programs running at the same time will cause problems, conflict with each other when a virus is detected, and might even crash the computer. That's the basic rationale behind McAfee telling you to uninstall Norton Antivirus first. As for how safe you will be without antivirus software; as long as you don't download any programs from dubious sources and install them you will be ok. 82.45.62.107 (talk) 22:09, 30 December 2011 (UTC)

Assuming you have some sort of firewall independent of your antivirus software (Windows comes with a decent one these days), you'll be perfectly safe assuming you only download and run things from trusted sources (what you should be attempting to do regardless). A lot of antivirus programs are very virus-like themselves these days, and you really don't want two running at once (at the very least not both doing the same thing [real-time scanning, etc.]). Many Norton products, for example, instead of uninstalling when you ask them to do not actually uninstall, but instead break your entire network configuration; hence the existence of the "Norton Removal Tool". I put Avira on Windows boxes these days, it's free and has been competitively ranked for several years running. ¦ Reisio (talk) 01:22, 31 December 2011 (UTC)

Download complete, no viruses detected. And no, I don't want to deal with anything strange. I only visited Wikipedia and the antivirus sites and opened the emails with links from those companies.Vchimpanzee · talk · contributions · 03:54, 31 December 2011 (UTC)

I should mention the donload took four hours. I guess my Internet is just slow. But that was the second time since it was going back from saying it was over halfway done to saying it was one-fifth done multiple times and I finally stopped it.

And just to clarify, people get virus messages all the time when they haven't done anything but go to a web site, and I stayed away from pretty much all of them in the interim. Someone claims to have gotten a trojan merely from clicking on a message board topic that has a post which contains links, which would be comparable to clicking on someone's talk page link here. I've gotten virus messages which turned out to be fake, and in the past week I've had three attack messages (something that never happened before) for which Norton dealt with the situation and no further action was required. I don't know what caused these attacks because the sites I went to were reasonably trustworthy (it could have been ads) although one appeared at the exact time a Java update message appeared. Investigating the situation showed something called a toolkit, though it wasn't in the full report once the error message was gone (an IP address for each attack was shown, and I'm not sure whether I saved those) and I forgot to save any Norton reports once I uninstalled Norton.Vchimpanzee · talk · contributions · 16:33, 31 December 2011 (UTC)

It's absolutely necessary you uninstall the old Antivirus program though. The auto-protect features stay resident and they'll interfere with each other leading to very slow performance and possibly crashes. I've seen it happen before and it's not fun to sit there waiting for 2 hours for a program to uninstall. If you're concerned about web-based drive by downloads (which is probably one of the greatest threats) you should look into NoScript or other similar script blockers. That should help your piece of mind. Shadowjams (talk) 22:20, 31 December 2011 (UTC)

If you don't do silly things, you don't need an antivirus. Even using Windows, some will dispute this, you'll be secure enough. Obviously, if you start clicking on all links of spam mails, downloading and running illegal software and the like, then nothing can save you. — Preceding unsigned comment added by 88.8.76.174 (talk) 23:50, 31 December 2011 (UTC)

The above advice is terrible advice for non-computer-experts like VChimpanzee. Ignore. For the record, I have abandoned McAfee and Norton and now recommend Microsoft Security Essentials, which has sped up various systems. Comet Tuttle (talk) 20:09, 1 January 2012 (UTC)

Using an anti-virus is not really an evident choice. If you care about security, it's much more important not to run any attachment that you get from an unknown source than using an anti-virus. Preventing is much more important than healing. 88.8.76.174 (talk) 00:55, 2 January 2012 (UTC)

I haven't run an anti-virus program in at least five years and I haven't gotten a virus in that entire time. I'm using Windows XP with automatic updates off. It mostly comes down to good judgement, rather than computer expertise. If a web page opens a popup saying your computer is infected with a virus, stop and think, instead of just clicking on everything it wants you to. How would a web site know your computer is infected? What is the name of the program they are hawking? Is it well known? That is an example of being cautious while using the Internet. Also disabling browser add-ons, like Java and Adobe Reader, will go a long way in preventing browser hijacks. I also run Adblock Plus and NoScript in Firefox, which prevent most exploits. When using IE, I use Privoxy. But, going back to the original question: Even if he is reckless while browsing the Internet, I sincerely doubt he will manage to find a malicious web site in the few moments he will be browsing for a new anti-virus program. Of course, if he already has a virus, then his searches may be redirected.—Best Dog Ever (talk) 21:08, 1 January 2012 (UTC)

Well, I have had the experience of seeing that because my computer is infected, I must now get such-and-such. Knowing that there is virus protection from another source, I know not to get theirs. I also realized getting theirs will actually cause a problem. I am normally not reckless at home and the only reason I would every go to a site I don't trust is accidentally typing the wrong thing, which can only happen if I go to one of four newspaper web sites, and for that I can use the methods I use for my email addresses and other trusted sites if I think about it. Obviously during the download, I had to be extra careful not to go anywhere I didn't trust--Wikipedia, McAfee, Norton, and my phone company's email service (and that was only for a McAfee link). My concern was those attacks Norton reported over the previous week, which I can't necessarily relate to a particular site I went to. One of them came as a Java message came up reminding me to update. Which I haven't yet.Vchimpanzee · talk · contributions · 21:40, 1 January 2012 (UTC)