Re: Commodore Emulators
> >> [Same goes for C64 emulators... there are still folks in chemistry and > >> biology and physics who have useful code that runs on the Commodore > >> machines.. even at Big 10 universities. ;)] > >> I have found this to be an EXCELLENT commodore machines emulator, which I've run on several linux distros :-) Shouldn't be too tough to port, if that is even necessary. Have fun! http://www.viceteam.org/ Be a better pen pal. Text or chat with friends inside Yahoo! Mail. See how. http://overview.mail.yahoo.com/ ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Re: Commodore Emulators
Ed Montgomery writes: > I have found this to be an EXCELLENT commodore > machines emulator, which I've run on several linux > distros :-) Maybe a fresh new BASIC would be better. It could certainly run much faster than one going through two levels of interpretation. The thought had already crossed my mind in fact. I think I can make it outperform Python; I have a bit of x86 JIT experience. (though actually one can write a regular compiler) A live view of the stack would really help people learn. I see 3 ways to do graphics: 1. expose the native 1200x900 (maybe a portion of it) 2. let the user choose, then scale coordinates 3. vector representation with scale-to-fit Color numbers might be 24-bit or 3-digit decimal. The former can represent more, while the latter is really easy to use. One can make a nice parser with Antlr. Since such parsers indicate the character position of an error, it is possible to show where an error occurs as the user is typing. I like the Atari syntax, but would of course want to support Microsoft's string features as well. Unicode is a must. For fun, CLOAD can be run over the audio ports. One could stick to the standard format, which survives the frequency dependant phase shift of a magnetic tape, or do something more modern. Question: if I jump from one for..next loop to another with a goto, where do I go when I hit the second "next"? I just tried two of the interpreters in Debian, and they didn't do the same thing. Of course, a truly bad-ass hacker would rip the FORTH out of the firmware, putting BASIC where it rightfully belongs. ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
New joyride build 305
http://xs-dev.laptop.org/~cscott/olpc/streams/joyride/build305/ -Calculate-12.xo +Calculate-13.xo --- Calculate-13 --- * Parser converted to unicode * Updates to improve translation #4527 * Mul/Div symbol i18n #4573 * Mul/Div button fixed #3526 * Addressed #4250 * Added palettes to buttons in toolbar -- This email was automatically generated Aggregated logs at http://dev.laptop.org/~bert/joyride-pkgs.html ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Acoustic distance measurement test results
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Joyride builds currently include my Acoustic Tape Measure activity, designed to turn any pair of laptops into a tool for measuring distance. Today, I decided to test the maximum range. I used two B4's running clean installs of joyride 289. I went to the MIT football field, because it is a large, flat, open space with clearly labeled distance markings. Unfortunately, there were no markings visible on the field, so I made measurements on the adjacent long-jump track, which is labeled in feet. Measurement worked perfectly up to 30 m (100 ft), with at most 1 cm of variability, and usually none. Measurement worked unreliably up to 40 m, giving spurious answers except during lulls in the wind. (Almost all microphones record high-amplitude noise in the presence of wind.) I have several ideas for increasing range (or equivalently, improving noise tolerance). However, I did not make any attempt to implement them, because it was too cold out for programming. I also encountered some difficulty when sharing the activity over the mesh at distances greater than 25 meters. This might be because the default mesh frequency (Channel 1) is the same as MIT's pervasive wireless network. After switching to mesh channel 11, I had no difficulty sharing over distances up to 40 m. - --Ben Schwartz -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.7 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFHQMRCUJT6e6HFtqQRAiaLAKCMbxGd4W0kk9WutMSuGrwxSohkQQCdECDB hTrx9Mz95WyPW4zFVmT3Ub0= =hRjf -END PGP SIGNATURE- ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Re: Acoustic distance measurement test results
On Sun, Nov 18, 2007 at 06:01:22PM -0500, Benjamin M. Schwartz wrote: > I also encountered some difficulty when sharing the activity over the > mesh at distances greater than 25 meters. This might be because the > default mesh frequency (Channel 1) is the same as MIT's pervasive > wireless network. After switching to mesh channel 11, I had no > difficulty sharing over distances up to 40 m. Your observations are consistent with mine, subject to variables you didn't mention. How high off the ground were the laptops? At ground height, with ears up, the node to node transmission distance is very small. That's why school server antennas will be mounted high. A football field normally has very little slope, so the terrain obstruction is easily understood. It might also be an area with a large radio noise background. By placing the laptops on the ground you may also have reduced the noise from nearby transmitters. With two laptops in a paddock or dirt road away from any city, I can easily get to 300m on with the laptops at 1.5m above ground. Nearby, I can reproduce 1.6km on a tar road with about 5% packet loss. -- James Cameronmailto:[EMAIL PROTECTED] http://quozl.netrek.org/ ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Re: Acoustic distance measurement test results
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 [EMAIL PROTECTED] wrote: > How high off the ground were the laptops? At ground height, with ears > up, the node to node transmission distance is very small. That's why > school server antennas will be mounted high. The laptops were sitting directly on the ground. > A football field normally has very little slope, so the terrain > obstruction is easily understood. Specifically, the laptops were sitting on the rubberized track surrounding the field. The surface appeared perfectly level to me, and free of obstructions apart from myself. It's entirely possible that what I saw was actually some unknown unrelated software bug. I wasn't intending to test wireless range, so I can't really say anything more conclusive than "it worked easily to at least 25m". - --Ben -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.7 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFHQNlHUJT6e6HFtqQRArurAJ0en7WqDgiPnXT5YUgI8SdKWtjK6ACfUVLG d29XGyyeDz+LXB2U5BWHwxA= =8Vqm -END PGP SIGNATURE- ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Re: Acoustic distance measurement test results
On 19/11/2007, at 11:31 AM, Benjamin M. Schwartz wrote: > The laptops were sitting directly on the ground. Good, consistent results confirmed. > Specifically, the laptops were sitting on the rubberized track > surrounding the > field. The surface appeared perfectly level to me, and free of > obstructions > apart from myself. Hmm, interesting. Black rubberised track may contain a lot of carbon, may end up behing a good reflector for the signal. Excluding grass improves the signal. -- James Cameron ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Re: Acoustic distance measurement test results
Heh. He said MIT; the field is surrounded by dormitories: very noisy environment -- Jim Gettys One Laptop Per Child ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Re: [Xiph-dev] What's the status of Xiph codecs support in the Helix project?
Ivo, perhaps we could come up wit ha set of compliance elements that typical users of OLPC laptops will need, as a case study for what free formats should be supported for other users to be considered 'complete'. Aaron, it would be tremendous to have speex working cleanly on the XOs, since a primary use case is sharing voice data via the cleanest lightweight recordings. (I would like to have that working seamlessly both in Helix and in gstreamer, but that's another issue.) SJ On Oct 8, 2007 12:06 PM, Aaron Colwell <[EMAIL PROTECTED]> wrote: > Comments inline > > Ivo Emanuel Gonçalves wrote: > > Hello lists, > > > > Personally, I have not yet had an opportunity to test the different > > components in the Helix project. As such, most of what I know comes > > from Wikipedia. > > > > In Wikipedia, it is stated that the Helix DNA Client supports Vorbis > > and Theora, but apparently, not Speex. Is it this true? > > This is true. > > > How hard > > would it be to port an implementation of Speex to the Helix Client? > > Not that hard. > > > Is anyone working in it? > Not at the moment. I'm essentially the maintainer of the Xiph related > code and haven't had the time lately to add speex support. At a minimum > I'm hoping to do a new release with the Theora Beta 1 decoder in the > next week or so. > > > What about Ogg Skeleton, which is now a > > requirement for Theora videos served under the video/ogg media type? > > > Has this been formally made a requirement yet? It seems like this is > still being hashed out on the xiph lists. I have yet to comment on the > proposal because I haven't completely groked the whole thread yet. For > now Skeleton is not supported. > > > In Wikipedia, it is stated that the Helix DNA Server only supports > > streaming of MP3 and Real Media formats. Why?? > Because streaming of Ogg has not been implemented yet. > > > The Ogg format was > > created mostly for streaming. > Ogg was created mostly for _HTTP_ streaming. The Helix server is > traditional RTSP streaming server. > > >That means that streaming Vorbis and > > Theora is (in theory) an easy process to implement for developers. > Not true. Since Ogg allows arbitrary chaining of streams, implementing > something that handles all of the various cases is quite difficult. > Ogg's ability to chain segments together that have different numbers of > streams in them are particularly taxing on the Helix Media Engine > implementation. > > > Then there's also streaming through RTP. Vorbis, Speex, and Theora > > may be streamed through RTP. > Implementing this has been on my list of things to do. This is > non-trivial especially if I want to properly handle chained streams. > > > > > With the Helix software becoming part of the XO laptop (the OLPC > > project) it is highly important that free formats work properly in > > Helix, but that doesn't seem to be the case right now. > > Since you haven't even used the Helix code I find it difficult to accept > your criticism that it isn't working properly. The code works great for > the codecs and modes of playback that I have implemented. My primary > focus was to get the most robust local playback of Theora & Vorbis files > that I could. Making the ogg file format plugin work with the Helix > Server and supporting Speex were secondary goals. I plan on adding > Speex, and RTP delivery when I get a chance. > > Since there isn't a compliance document for ogg support and no specified > minimal codec support, I think it is a stretch to say that Helix doesn't > support free formats properly. Ogg is woefully under specified > especially in the chained and multi-stream cases. Having a document that >strictly outlines how to handle funky chained files (ie. audio-only, > followed by audio/video, followed by a segment with 2 video streams) as > well as files with say 2 audio tracks or 2 video streams would be of > great help and would provide a way for all of the implementations out > there to converge on a single interpretation. > > This has been a side project of mine for several years. I haven't spent > much time on it lately because I have gotten little to no feedback on it > . I've pretty much interpreted that as any of several things; users > are happy with the current code, they don't care about this work, or > they are unhappy but don't post anything to the list so I can fix it. In > all of these cases there isn't much incentive to work on the code since > there is no outside feedback. Also since there really isn't a minimum > bar for claiming compliance, spec compliance isn't a motivator either. > > Aaron ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
