Sounding Out with the OLPC XO
I knew that the XO was able to play media files in various formats, but at first I was mystified as to how to access such files. The Sugar interface doesn't provide a file manager a la Nautilus or Konqueror. Instead, the Journal activity lists all work done on the machine in a kind of diary. All saved work also is listed there, including recordings and other media files, and I needed only to double-click on an item to view or listen to it.
Players are invoked automatically for a selected file. On the base system, I had no trouble playing MP3, Ogg and WAV audio with the players in the eToys and Browser activities (Figure 6). I also played video files in AVI, MPG and Ogg formats, with the understanding that playback was not likely to be cinematic with a 433MHz CPU. However, videos made on the XO are recorded at 30 frames per second and played smoothly (in their original 640x480 resolution) when transferred to my more powerful desktop machines.
Audio recording on the XO is done with the Recorder activity, a simple utility for capturing pictures, video and sound. After selecting the particular media task, a “ready to record” icon appears (an eye for video and lips for audio). Click the icon to start recording, and click it again to stop the process. The file is named and saved automatically, and it can be previewed directly from the Recorder.
I tested the audio recorder with the internal microphone and with an inexpensive external mic. To its credit, the internal mic recorded with less noise and a stronger signal. I've since decided to do all casual recording on the XO with its own microphone. Settings for the microphone input level (and all other audio channel levels) can be managed with alsamixer or any similar sound card mixer, but I found the default levels to be adequate under relatively calm acoustic conditions.
The XO's internal speakers are okay for basic purposes, but they will not provide high-fidelity sound. For a better audio experience, I suggest either good-quality headphones or a set of powered external speakers. Surround sound playback is supported by the XO's audio chipset, so you may want to attach a 5.1 system. Alas, I was unable to find technical specifications on the integrated speakers, but it's obvious on listening that bass response is almost nil, which gives the audio a thin and tinny sound. This is especially unfortunate with regard to the TamTam software—it simply sounds far better on external speakers.
Thanks to the pioneering work of Michael Gogins, Steven Yi and other developers, Csound now includes a number of Python-related opcodes. Python is rather ubiquitous in the XO's software structure, and Csound is the audio engine for the machine, so it's a wrap that the XO might be an excellent platform for experimentation with the world's most powerful music and sound programming language. Alas, I've run out of space to describe adequately the XO's Csound/Python potential in this article, but I can recommend interested readers to the OLPC Wiki page on Csound. A few pointers to relevant projects and activities can be found there, and further information can be discovered in the Csound mailing list and its archives. Jean Piche and Rick Boulanger are Csound gurus, so I have great expectations for working with the language on this machine. If TamTam is any indicator, the creative possibilities are truly impressive.
I loaned the machine to two students, both of whom had trouble figuring out how to save their work. They discovered how to use the Recorder and other activities with little difficulty, but the Save procedure was dark to them until I explained the Journal and its functions. Documentation is entirely Web-based, and the students said it was a hassle to switch between the Web browser and their current activity. Of course, once they learned how to use the Journal, all was well.
The only other problematic area for me was the wireless connectivity. Connections are hard to come by in my area, and I would have been happier with an Ethernet port. However, I understand the design consideration, and my USB-to-Ethernet adapter is already on order.
If you've been waiting to purchase one machine for yourself or thousands for children in the remoter parts of the globe, just do it. The XO is intended to spread happiness and joy throughout the world, but the project needs your help to achieve this lofty goal. See the OLPC Wiki for more information on how you can get on board.
So, do I like the XO? I love this machine, and I heartily recommend it to anyone anywhere. It squeezes more juice from a relatively low-powered CPU than I would have thought possible, the TamTam software's performance is nothing short of astonishing, and the fun factor scales right off the charts. The XO gets five stars for overall excellence, and if I had to choose a single word to describe the machine and the experience of using it, that word would be joyous.
Similis sum folio de quo ludunt venti.
Practical Task Scheduling Deployment
One of the best things about the UNIX environment (aside from being stable and efficient) is the vast array of software tools available to help you do your job. Traditionally, a UNIX tool does only one thing, but does that one thing very well. For example, grep is very easy to use and can search vast amounts of data quickly. The find tool can find a particular file or files based on all kinds of criteria. It's pretty easy to string these tools together to build even more powerful tools, such as a tool that finds all of the .log files in the /home directory and searches each one for a particular entry. This erector-set mentality allows UNIX system administrators to seem to always have the right tool for the job.
Cron traditionally has been considered another such a tool for job scheduling, but is it enough? This webinar considers that very question. The first part builds on a previous Geek Guide, Beyond Cron, and briefly describes how to know when it might be time to consider upgrading your job scheduling infrastructure. The second part presents an actual planning and implementation framework.
Join Linux Journal's Mike Diehl and Pat Cameron of Help Systems.
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|SUSE LLC's SUSE Manager||Jul 21, 2016|
|My +1 Sword of Productivity||Jul 20, 2016|
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- The Firebird Project's Firebird Relational Database
- Stunnel Security for Oracle
- My +1 Sword of Productivity
- Non-Linux FOSS: Caffeine!
- Managing Linux Using Puppet
- SUSE LLC's SUSE Manager
- Murat Yener and Onur Dundar's Expert Android Studio (Wrox)
- Doing for User Space What We Did for Kernel Space
- SuperTuxKart 0.9.2 Released
- Google's SwiftShader Released
With all the industry talk about the benefits of Linux on Power and all the performance advantages offered by its open architecture, you may be considering a move in that direction. If you are thinking about analytics, big data and cloud computing, you would be right to evaluate Power. The idea of using commodity x86 hardware and replacing it every three years is an outdated cost model. It doesn’t consider the total cost of ownership, and it doesn’t consider the advantage of real processing power, high-availability and multithreading like a demon.
This ebook takes a look at some of the practical applications of the Linux on Power platform and ways you might bring all the performance power of this open architecture to bear for your organization. There are no smoke and mirrors here—just hard, cold, empirical evidence provided by independent sources. I also consider some innovative ways Linux on Power will be used in the future.Get the Guide