Wikipedia:Reference desk/Archives/Computing/2015 September 18

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September 18

Help identifying printer

I remember seeing a video a few years ago of a computer printer that used a normal ballpoint pen as its ink source. It worked much like a seismometer with an arm that held the pen and moved it from side to side, pressing down as appropriate to render the printout. Except instead of drawing earthquake graphs it could print text and monochrome images from a computer. Does anyone know what this type of printer is called? Is there a Wikipedia article on it? Thanks for your help — Preceding unsigned comment added by 117.178.158.168 (talk) 14:58, 18 September 2015 (UTC)

That sounds like a pen plotter. -- Finlay McWalterᚠTalk 15:07, 18 September 2015 (UTC)

... although a pen plotter didn't quite use a "normal ballpoint pen", but rather a technical pen system with a short, stubby pen made to be held by (or screwed into) the plotter's head: they're not ergonomically suitable for using hand held. And, like other technical pens, both the pens and the inks were quite expensive. -- Finlay McWalterᚠTalk 15:14, 18 September 2015 (UTC)

Thanks that seems to be exactly it! The article even says "Ball-point plotter pens with refillable clear plastic ink reservoirs are available. They do not have the fading or wear effects of fiber pens, but are generally more expensive and uncommon. Also, conventional ball-point pens can be modified to work in most pen plotters." Now that I have the name I even found some holding a normal pens [1] [2]. Maybe the one I saw was a diy project or something. Anyway, you answered the question thanks! — Preceding unsigned comment added by 117.178.158.168 (talk) 15:31, 18 September 2015 (UTC)

Of peripheral interest, there were a few low cost plotters of this type produced for 8-bit computers of the 1980s era, e.g. the Atari 1020. --LarryMac | Talk 21:01, 21 September 2015 (UTC)

Free LAMP stack hosting

I will be teaching a course in LAMP stack development. I'm trying to find a free LAMP stack hosting service for the students to use. I assume that any service I find will have ads in some way, but I haven't been able to find any free LAMP hosting. Everything that I find claims to be free and, just when you get to the point of setting up the server, you have to choose a monthly billing plan. Are there still absolutely free LAMP stack hosts available? I don't care if you can't assign a domain name to the website. I just want to be able to get to the CLI and do development. 209.149.113.66 (talk) 15:13, 18 September 2015 (UTC)

"Free" Web hosts are notoriously terrible. Most won't give you CLI access, and the ones that do will have a strictly limited environment. You generally won't be allowed to install things, modify many settings, etc. If you want a decent hosted development environment you'll have to pay at least a little. Are you sure the institution you're teaching for won't cover the cost? Many large institutions with their own IT infrastructure would host it themselves, but of course I know nothing about your situation. --71.119.131.184 (talk) 18:22, 18 September 2015 (UTC)

If this is only for your students, why not get a few old and obsolescent computer and create your own hosting system? Just create enough VM's (or virtual severs) for everyone. The bandwidth is bound to be small (unless your students are also into porn). --Aspro (talk) 19:22, 18 September 2015 (UTC)

I take it that that the OP is from a third world county where most people starve and money is in very short supply. If he lives (in say) Africa he may be able to join WebAfrica Their Linux Premium Plus is less than I spend on a single night out. If you would like to email me, I will Pay Pal transfer a years hosting for you and your students. Students are our future. --Aspro (talk) 21:21, 18 September 2015 (UTC)

Thank you, but this isn't a third-world country course. It is more like a third-world county. I will be teaching at a community college with very few resources. The students are all on tuition assistance from the state. They have a computer lab, but it is windows-only and doesn't provide any user space. There is only the "guest" account that gets wiped with a new image every day. So, my plan is to have the kids put Putty on a USB stick and run it to connect to a LAMP server. Then, do all development there. I don't personally own a LAMP server that they can use, so I am trying to find one that they can use for the 4 months of the semester. 209.149.113.66 (talk) —Preceding undated comment added 12:43, 21 September 2015 (UTC)

Could you not install one in a VM on one of your Windows hosts? (Or all of your windows hosts - that way each student could have their own!).--Phil Holmes (talk) 14:44, 21 September 2015 (UTC)

Wow, I didn’t know things were that bad in South Carolina. Your in one of the riches countries on this planet but your students, out there in the sticks, are not sharing in the wealth (Barack are you hearing this). What pops into mind, is that although you are a Windows only environment, leave the PuTTY to one side for a moment. A lot of windows only environments now use Linux servers for ease of maintenance. What I think may be a solution is to use a Linux Server on a pen-drive that has a windows compatible NAS file, (to keep life simple). Ubuntu Servers and and many other Linux distributions will go onto a bootable pendrive. Here are some others: Portable Web Servers Category. Remember, pen-drives can wear-out so always back up and have a few spare servers. I can't add any more to that because I don't know your exact circumstances are. Also, as you live in one of the richest countries on this planet I don't feel like subsidizing your badly funded education (?) system without your Government sending me a fair remuneration (Barack are you hearing this). No offence meant your students, I wish them well and sure they will do well under your mentorship. As -Phil Holmes suggests. I think you have a very good reason to ague that you need a VM that doesn't get wiped every day. What it the IT managers job for if it not to provied IT support? Get back in the future and let us know how you get on.--Aspro (talk) 15:08, 21 September 2015 (UTC)

Final thoughts: Remember, setting up a VM is is not going to cost your faculty any money really. The are still paying their IT manager regardless of whether he is sting down eating doughnut as he surfs the web or picking his nose. All they need to do is get him to pull his finger out and provide you and your students with what is needed for the purpose of education. Still, I like the pen-drive solution though. Not as good a proper solution but it will give your students the experience of how to carry around their very own server. Maybe introduce them to both. They can then play, experiment and learn with adim access on the pen-drive and mess it up all they want -with no harm done. Just a thought.--Aspro (talk) 15:40, 21 September 2015 (UTC)

I am trying what, for me, will hopefully be the easiest route. I'm trying to get the IT staff to allow me to put a LAMP server on the school's network. I will have complete control over the installation and configuration and I can create an account for each of the students. The hard part is convincing the IT staff that it won't be a security risk. They are already freaking out and labeling me a major security threat for suggesting that the students plug a USB drive into their computers. 209.149.113.66 (talk) 13:17, 22 September 2015 (UTC)

Now getting your message loud and clear. Take a different route. I think I can take it that your desire to teach is more than equal the the administrators egos – otherwise you would not be taking the trouble to post here, rather than just accept the current situation. Use you network of friends and relatives -even if you have not spoken to them for years. The etymology of Dr. is one who can teach. This honour is something that many instinctive latch onto. Just like here on Wikipedia, we answer questions pro-bono, derived from years of dedicated study – and which we 'feel' a desire to pay pay back -just like teachers. So, explain the situation to all that will listen. birds of a feather flock together, so you may well have many IT literate friends who both are qualified and get involved with local politics and be familiar with thoughts of Niccolò Machiavelli. They may see your point and be able and willing to ask the facility (without mentioning your name) that they hope the faculty provides the very basics that students need. Out of the pot of money the faculty has, the emphasis should be on what does the most good. Amongst your network of friends you must find some one who knows how to focus that obvious point upon them. Otherwise, face facts and relocate to another part of the world were you skills are more valued. The salary may be a little less in Dollar terms but the cost of living is lower and the quality of life is much better. If you wish to remain in the US -then show those sons of bitches you mean business.--Aspro (talk) 20:51, 22 September 2015 (UTC)

Hum. Just a thought. As you're in a widows only environment and their freaking out about pen-drives. They may be worried about worms that can so easily infect windows via pen-drives. Yet they should know that a properly configured VM isolates worms (on a linux server anyway). And as long as they don't give you admin access to the whole server, any problems that arise, are theirs and theirs alone. But then again, I guess I’m only preaching to the converted.--Aspro (talk) 21:10, 22 September 2015 (UTC)

Download audio from video

How can I download only the audio from an youtube or any other online video? Thank you.175.157.53.223 (talk) 15:23, 18 September 2015 (UTC)

This online service [3] might be helpful. SemanticMantis (talk) 19:04, 18 September 2015 (UTC)

Also, I think DownloadHelper (which is free) lets you choose the format to save the file in, and some of the formats are audio only. OldTimeNESter (talk) 12:29, 19 September 2015 (UTC)

Creepy Facebook friend suggestions -- Facebook Google connection?

I'm getting increasingly concerned about where Facebook gets its "People you may know" friend suggestion list from. I'm not very active on Facebook, and have few Facebook friends. Yet several of the suggestions are very precise. Problem is, I have no idea where they get the information from, and I don't like the idea of having all sorts of details about my personal relationships floating around in cyberspace. Here is the list:

1. Wife of nephew. 11 mutual friends. OK.
2. Husband of colleague. No mutual friends. I am not a Facebook friend of this colleague. NOT OK.
3. Niece, 8 mutual friends. OK.
4. GF of son, 10 mutual friends OK.
5. IT consultant used by my employer. Extensive communication a couple of years ago, including using my private Gmail account. No relationship through friends of friends as far as I know. Definitely NOT OK.
6. GF of nephew, 8 mutual friends, OK.
7. Nephew, 9 mutual friends, OK.
8. Relative, 7 mutual friends, OK.
9. Close colleague, no mutual friends, but Gmail contact. NOT OK.
10. Close colleague, no mutual friends, but Gmail contact. NOK OK.

I have not fallen into the "please give us your email password" trap. So what's going on?

--NorwegianBlue ^talk 21:46, 18 September 2015 (UTC)

Even if you did not share your Gmail contacts, there people obviously could have shared theirs (which includes you). It's not enough that you take care about not releasing too much private information. People around you should also take care.

Add to it that FB can analyze the information it gets. FB could also have gotten the information through their own mining efforts. You and your colleagues disclosed your place of work somewhere, they picked the information and concluded that you could know each other. They obviously use methods more refined than just looking at the friends of friends as potential FB buddies. It's all statistics, but probably it does not have to be a very sophisticated algorithm. --Scicurious (talk) 22:09, 18 September 2015 (UTC)

WP:OR - I share your concern. FB has suggested many people that I may know with zero mutual friends that are concerningly accurate. One unsubstantiated idea - either you have the person's phone number and name in your phone contacts, or vice versa. At least, I think this has been a possible explanation for my experiences. I can't think of any other way that they would know that I know past landlord - we live in different states, have zero personal connections or friends in common etc. I can't think of any way this would have come up through traditional statistical inference. But he likely has my real name and phone number on his phone, and I do have that phone number in my FB profile... of course this wouldn't make sense if neither party used the FB app on a smartphone. SemanticMantis (talk) 22:25, 18 September 2015 (UTC)