When I’m not thinking in or of computer languages, one of the things that I find consistently interesting is natural languages. As such, I’ll occasionally spend some time simply puzzling over bits of language (for which purpose Language Log is an excellent feed of topics).
As it happened, I spent some time today informing myself more on the fairly well-known conlangs Esperanto and Lojban. I find each of them interesting, although my usual pragmatic approach to things probably means I’ll never do any serious study or either.
The point of this rambling, however, is that an exercise in Lojban For Beginners challenges the reader to spell their name using the lojban orthography.
Moving on from my previous post (in which I muttered sullenly about brain-dead packaging of software for Linux), I began hacking on my Chronos proper tonight. Read on for some juicy tidbits.
Initial build The first order of business was to set up a toolchain targeting MSP430. Since I’m running Arch on my primary development system, it was a simple matter to build gcc-msp430 from the AUR.
With that, I was ready to try compiling things. I assumed (correctly) that the provided firmware would not build on GCC without modification, but a little googling pointed me to OpenChronos, which effectively takes the stock firmware, makes it build with any of several compilers (TI’s compiler included with CCS, IAR’s, and GCC).
I recently acquired a TI eZ430-Chronos watch/development platform. It’s a pretty fancy piece of kit just running the stock firmware, but I got it with hacking in mind, so of course that’s what I set out to do. Little did I know that TI’s packaging of some of the related tools is a good lesson in what not to do when packaging software for users of any system that isn’t Windows..
The first thing to do when working with a new platform is usually to try out the sample applications, and indeed in this case I did exactly that. TI helpfully provide a distribution of the PC-side software for communicating with the Chronos that runs on Linux, but things cannot be that easy.
Casio’s FX-CG, or Prizm, is a rather interesting device, and the programmers over on Cemetech seem to have found it worthwhile to make the Prizm do their bidding in software.
The Prizm device itself is based around some sort of SuperH core, identified at times in the system software as a SH7305 a “SH7780 or thereabouts”. The 7780 is not an exact device, though, and it’s likely a licensed SH4 core in a Casio ASIC. Whatever the case, GCC targeted for sh and compiling without the FPU (-m4a-nofpu) and in big-endian mode (-mb) seems to work on the hardware provided.
I nearly always find it interesting to muck about in someone else’s code, often to add simple features or to make it do something silly, and the Linux kernel is no exception to that. What follows is my own first adventure into patching Linux to do my evil bidding.
Aside from mucking about in code for fun, digging through public source code such as that provided by Linux can be very useful when developing something new.
A short story I was doing nothing of particular importance yesterday afternoon when I was booting up my previously mentioned netbook. The machine usually runs on a straight framebuffer powered by KMS on i915 hardware, and my kernel is configured to show the famous Tux logo while booting.
I sometimes use Links on various computers when I can’t be bothered to deal with a full graphical environment and just want to look something up. Given I also try to ensure that this site renders in an acceptable manner in text-only mode, Links is indispensable at times.
Now imagine my surprise when I discovered that Links will try to transliterate Japanese kana (a general term for the scripts in which characters correspond to syllables, rather than more abstract ideas such as in kanji) to some extent.
Examine the page header and title readout at upper-right. In that shot, Links has translated the kana in my page’s header to a reasonable romanization- the pronounciation of those characters would be Tari, as in the beginnings of ’tan’ and ‘return’.
One of the fun things to do with computer languages is abuse them. Confusing human readers of code can be pretty easy, but it takes a specially crafted program to be thoroughly incomprehensible to readers of the source code yet still be legal within the syntax of whatever language the program is written in.
Not dissimilar from building a well-obfuscated program is using esoteric languages and building quines. All of these things can be mind-bending but also provide excellent learning resources for some dark corners of language specification, as well as the occasional clever optimization.
Obfuscation It’s not uncommon for malware source code to be pretty heavily obfuscated, but that’s nothing compared to properly obfuscated code.
In a fit of boredom this evening, I tried to see what the speech recognition in Windows 7 would give back when I made raptor noises into it. The result.. speaks pretty well for itself:
F and has and has a Hack it has A hack who know Her house Just how hot enough And who know how It has had To add up data at data to go out and It’s all of all Go ahead goal happened: how has a Staff headed to a
And if his own booth for th FFI have had for the hand-held her and who often have no
I recently converted the root filesystem on my netbook, a now rather old Acer Aspire One with an incredibly slow 1.8" Flash SSD, from the ext3 I had been using for quite a while to the shiny new btrfs, which becomes more stable every time the Linux kernel gets updated. As I don’t keep any data of particular importance on there, I had no problem with running an experimental filesystem on it.
Not only was the conversion relatively painless, but the system now performs better than it ever did with ext3/4.
Conversion Btrfs supports a nearly painless conversion from ext2/3/4 due to its flexible design.
It’s a Christmas miracle! There’s a new post! Or maybe not, but take what you can get. Here are some fun links.
It’s hardly a secret that LEDs may also be used as rather poor photodiodes, but this paper from Mitsubishi Research Laboratories goes into great detail in how such properties may be exploited for short-range wireless communication with only a few parts on a microcontroller. Boing Boing has a neat gallery of technology in use at the US Library of Congress to digitize collections. A ridiculously nice panorama of the Milky Way as seen from the summit of Chimborazo, the highest peak in Ecuador.