lardbucket: blog


Calcsy – See your calculator on your computer

Filed under: Education, Math, Programming, School, Technology — Andy @ 9:17 pm

Calcsy LogoCalcsy is a tool you can download and use on your computer to show (and save) the screen of your TI-84+ or TI-89 Titanium calculator.

It’s useful for projecting the screen large enough for other people to see, or for taking a screenshot to use in instructions. For example, I’ve used it in teaching how to graph functions on a calculator, and I suspect it will be similarly useful to other people.

I first wrote Calcsy almost two years ago, and have been (very) slowly making it better since then. It’s now to a state where I think it’s reasonable to release. At the moment, it’s only available for Mac OS X, although it should be possible to port to Windows if there’s enough demand. Hopefully it’s pretty self-explanatory, but feel free to let me know if you have any questions.

All you need is a TI-84+ (or TI-84+ Silver Edition) or TI-89 Titanium and a USB cable to plug it in to your computer. The program is free, and you don’t need any special software on your calculator. (You also don’t need one of the special “Presentation Link” adapters – your computer and a normal USB cable works just fine.)

Other details of note: I suspect it won’t work with the very new TI-84+ Color calculators, but I’m happy to try to make it work if someone wants to send me one. Also, the logo was made by David Felice, so thanks are due to him.

Anyway, it’s free, go check it out. Let me know if you have any questions/comments/problems/etc.

Andy Schmitz


Flat World Knowledge

Filed under: Education, School — Andy @ 10:00 am

Over the past few years, a publishing company called Flat World Knowledge has been publishing a number of textbooks in several subject areas, from history to psychology to math. One of the features they have advertised is their “open” books, meaning in part that their books are available for free online to everyone. Until recently, this was nearly unheard of: students can now legally get their textbooks for free (while paying for extra features if they want them). While I had not heard about their books until recently (likely because they have few math books), this is definitely something I like, at least in the abstract.

Unfortunately, Flat World Knowledge has recently decided that the “open” model will not work for their publishing, because not enough people were buying their books. As much as I would like to argue that such a model should work, I’m sure they have more data than I do, and have undoubtedly done their analysis and decided that such a business model is unsustainable for them at this time. While I hope that they are able to offer their books in an open manner again in the future, they have at this point decided to restrict the way in which their books are available on their website, starting on January 1, 2013. (They have already started implementing this change, as well.)

The good news is that they previously published their books online under a Creative Commons license, a common license which allows redistribution (in particular, the attribution, share-alike, non-commercial license, version 3.0). This means that people have the right to continue to redistribute copies of the books, if they happen to have them.

I am still a bit disappointed: I would have liked Flat World Knowledge to succeed in their open publishing experiment. I would have liked more books to be available, and I would have liked even more companies to follow in their footsteps. Unfortunately, it appears as though that area may remain the realm of private or government financing for the moment.

I would like to remark for the inevitable debates to ensue in unseen boardrooms in the future that the Creative Commons license likely allowed Flat World Knowledge to have so many books. In nearly every foreword I had read, the authors extolled the open license of the book as a primary reason for publishing with FWK. Were it not for this license, it is entirely probable that FWK would not be in such a favorable position. The ability of others to share your books should be regarded as the feature so many authors see it as, rather than a liability.


Merry Christmas, Again

Filed under: General — Andy @ 12:00 am

Another year has passed, and with just one [other] published post here. I’m slowly starting to have more discretionary time, and to get some projects closer to completion. Barring any major surprises, I should have at least one or two things to release next year. (The problem, of course, with long-running projects is that there are few of them, and if I should decide for whatever reason to not release them, they tend to disappear entirely.)

In the arbitrary milestones department, GraphSketch passed 1.5 million graphs delivered a while back, and I should really pay attention for the 2 million milestone that’ll be coming up sooner or later. I’ve also obtained a full-time job, which surprisingly seems to take less time than school did at times. It seems to be pretty nice, although, as with many things, I haven’t yet taken the time to step back and thoroughly examine how it’s going. There will probably be more comments on the job in the future, but for the moment, allow me to disclaim everything posted here and say that unless an exception is clearly noted in a post, the posts on this blog represent only my own views (if that), and have never been, and will never be intended to represent the opinions of my employer, school, friends, colleagues, or anyone else.

So, this makes for a particularly lackluster sometimes-annual update, but it’s about everything I have to say. Have a Merry Christmas if that’s your thing, and have a great new year when that rolls around. With any luck, I’ll have something new to post in January.

Until then,
Andy Schmitz


Getting Complicated, Embedded YouTube Videos

Filed under: Hacks, School, Technology — Andy @ 3:29 pm

So, earlier today, Karl Fisch asked for a copy of an Olympics video from NBC’s website to use in his school. A number of the “standard” ways of getting the video didn’t seem to work, so I figured I’d pitch in. By the way, the first thing to try (if whatever addons you might have to download YouTube videos don’t work – although I don’t use any myself, I’m told they didn’t work in this case) is to click the YouTube button.

The YouTube button will usually open the video up into YouTube’s website, where most addons for downloading a video will work better, and there are plenty of other websites happy to help you.

In this case, clicking the button only got to the NBC Olympics home on YouTube. A quick search of the channel showed that the video I was looking for wasn’t on the NBC Olympics channel, and I’d have to find another way to download it.



Portrait: Linux System Management Tool

Filed under: General — Andy @ 3:13 pm

So, over the past year or so, I’ve been working on a project I’m calling Portrait. It’s [going to be] a piece of open-source software system administrators can use to manage Linux computers. Unfortunately, there’s still a fair amount of work to be done on Portrait, because my free time is pretty sparse. I’d also like to launch a hosted version of Portrait, which people can use if they don’t want to deal with setting up and maintaining a copy of the software. To help get both of those things moving, I’ve set up a Kickstarter project, titled simply Portrait: Linux System Management Tool to raise funds to let me work on Portrait over the summer and set up a hosted version that people can use.

Most of my readers won’t personally have any use for a Linux system management tool, but if you happen to know anyone you think might find it useful, I’ll ask you to please pass the Kickstarter project along to them. If you’re interested yourself, please head on over to the Kickstarter project page, where I’ve put much more information on exactly what Portrait will do.

Andy Schmitz


FABridgeC: A smaller FABridge

Filed under: Open Source, Programming — Andy @ 12:31 pm

I was working with some JavaScript libraries this week, and happened to have a use for Adobe’s Flex Ajax Bridge (also known as FABridge). However, I’m trying to work with Closure, and the most common FABridge.js is a rather large 18 KiB that doesn’t really work very well with Closure’s compiler.

So, I took a few hours to go through and make it work with Closure, and then to make it work compiled outside of Closure in case anyone else wants a smaller version of FABridge. I’m calling the result FABridgeC, and you can read more about it on the project’s GitHub page. For most users, this is a minified FABridge.js (or if you prefer Closure’s terminology, a compiled FABridge.js) in just 5.4 KiB that can be dropped in instead of FABridge.js, and should work in exactly the same manner as the original for almost everyone. (There are a few minor caveats explained on the project page.) If you’re using FABridge at the moment, try dropping it in place of your existing FABridge.js, and let me know how it goes!

Feel free to send me a message via GitHub (I’m aschmitz, the repository’s owner) or leave a comment here with any questions, problems, or other comments.

Andy Schmitz


Testing Help?

Filed under: General — Andy @ 11:30 am

I’m working on a program that will let users of TI-84+ or TI-89 Titanium calculators see their calculators on the computer screen, and take screenshots. (If you have a TI calculator that has a USB port and ┬áisn’t an Nspire, you’ve probably got one of these.)

Right now, it runs on the Mac only (although that will hopefully change in a while). It works on my Mac, and at least one other, but I’m looking for one or two more test cases. If you have a TI-84+ or TI-89 Titanium, a USB cable that will plug into it and your computer, and one of the following computer setups, please give me an email at so I can send you a copy and see if it works. The whole process of testing it out should only take a minute or so.

I’m looking for:

  • Mac OS X 10.5 (Leopard) on a PowerPC processor

If you’re not sure what operating system or processor you have, just click on the Apple menu in the upper-right corner of your screen, and click “About This Mac.” Your version of OS X will be displayed (I’m looking for anything that begins with 10.5), and your processor will be shown as well. Please let me know which version and processor you have when you email me, so I know which one you’re testing.


Andy Schmitz


Announcing scavhunt

Filed under: Open Source, Programming, School, Technology — Andy @ 5:48 pm

Since the end of Dan Meyer’s SLV SCAV, it’s been in the back of my mind to get the source code available to more people, and there was at least some interest from others about running their own copies.

As a result, I took the time to go through the code, remove any references to the school, students, or teachers that I could find, and generally cleaned the code up for release. I changed the name to “scavhunt,” and made a working version that I can release. I’m happy to say that the code is now available as open source (AGPL v3), from GitHub as scavhunt.

Unfortunately, I haven’t yet had the time to properly document things. As it is, if you pull the code down (either use git if you’re comfortable with it, or download a tarball/zipball with the “Downloads” button in the upper-right corner of the GitHub page), it should be a working scavenger hunt, although a bit sparse. There are a number of files you should modify, and some directories that need to be writable by the web server, but those are all documented on the file (and also on the GitHub page for the project). It comes with two example questions as a basis for writing your own, although additional question types exist in the code as well.

So, the code is now available for your use, however you see fit (as long as it complies with the AGPL v3, which is pretty relaxed in terms of usage). If anyone has any questions, feel free to contact me at andy [dot] schmitz [at] gmail [dot] com, or potentially file an issue on GitHub (although I’m new to GitHub, so it may take me a while to figure out how to respond). Unfortunately, at the moment, I don’t have enough time to necessarily improve the code in the ways I would like to, but I can certainly answer questions and respond to pull requests from those who would like to improve it on their own. Contributing your improvements back would be greatly appreciated. And hey, if you use it, I’d appreciate an email or tweet (@aschmitz) to see where it’s in use.

Andy Schmitz

P.S. This is indeed where the scoreboard movement tracking code came from, so that section is rather well-commented. Unfortunately, the rest is less documented, but hopefully understandable.


Leaderboard with Movement Tracking

Filed under: Hacks, Programming — Andy @ 9:00 pm

In putting together SLV Scav with Dan Meyer, I ended up writing a (relatively) simple script for generating a scoreboard with rankings, as well as the amount the rankings had changed. It looks something like this: (picture from Dan Meyer, names blurred to protect the innocent)

Dylan Faullin asked for more information, so I’m posting most of the relevant code here.



VP8, WebM, and FFmpeg

Filed under: Programming, Technology — Andy @ 8:06 pm

So, today at Google I/O 2010, Google announced that, along with a number of other groups, they were releasing WebM, a video container and codec. (WebM itself specifies the container, which is a variation of Matroska, as well as the video format, the newly-released VP8, and the audio format, Ogg Vorbis.) I won’t get into the technical details of the codec, as I’m not really qualified to do so, but a developer for x264 has a reasonably thorough review of a prerelease version of the code here.

The interesting part of VP8 / WebM is that it is a reasonably good video standard that may be theoretically free to use. (The currently popular “best” video format, H.264, is riddled with patents and requires licensing for most uses, although encoding video that’s available for free doesn’t require payments until at least 20151.) It doesn’t appear as though anybody is claiming that WebM is the best video format available, but it’s reasonably good, and potentially free to use. (It’s impossible to know whether someone else has patented parts of the standard, because that would require examining every software patent ever granted, which is not going to happen.) For some background, the video codec, VP8, was produced by a company named On2 before Google bought them last year. Its predecessors, VP6 and VP7 were used for video in Flash2 and the video in Skype3, respectively.

Most of this will be fairly boring to anyone who normally reads this blog, but if you’re interested in a way to encode WebM videos yourself in Ubuntu, read on.


  1. The press release PDF from MPEG LA, the group licensing the patents for H.264
  2. An Adobe article on encoding video for Flash using VP6. An earlier version of this post claimed VP6 was the original codec for Flash, which is false.
  3. A press release
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