Posted on 11-09-2006
Filed Under (Gallery, Photography, Life) by esden

You probably know it already but I am back from Schotland. I spent 10 days on the Ile of Arran with some friends. We Made a 100km tour around it. I shot about 460 images and hope that there will be something useful among them. But you will have to judge for yourself.

We arrived back in germany last friday and I was fighting with my emails and rss feeds. Now I am catching up with other things. I hope that I will have enough time to work through the Scotland images in the next days and put them online in my gallery.

My photoblog seems to be working pretty well. It was running on auto pilot the last two weeks and I think that it is a pretty nice thing. I will now put more images online and they will get visible over time. That makes the blog regular and I do not need to spend so much time on it. But I will now start answering your comments in the photoblog. If you provide your email address then you will also get an email. (the email address will not get posted so do not fear).

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Posted on 29-08-2006
Filed Under (Lisp, Computerworld) by esden

Some days ago I watched some Lisp Machine Videos. These films show what it was like to use a lisp machine and code on it.

I really have to admit that I was not surprised to see what wonderful ideas the guys had back then. Current OS’s still have a long way to go to incorporate (copy) the functionality you had 20 years ago in LispM Operating systems like Genera. Apple as always is on the front line of incorporating this old stuff. For example Time Machine. The new feature that will be there in Leopard (the next version of Mac OS X). The idea of easily going back in time and looking at your files was there 20 year ago.

Still as I now know Time Machine is still far away from the idea the LispM developers had. There you had a filesystem that had versioning built in. You can tell you do not save files just like that. You save patches to your files. That is somehow comparable to having SVN as your filesystem. Just a bit more sophisticated.

Sure that is not the only thing. There are tons of others. Like objects that are mouse sensitive depending on what you are doing. Accessing the displayed object structures that are behind that what you see. And many more…

I do not want to let myself get carried away too much. The condensed idea I wanted to share with you is the following. Genera is amazing. And if you think that any currently known OS is cool then you know nothing. And if you think that Java and Eclipse are cool then you live in the stone age in the matter of knowledge.

Sit down, learn lisp. It may hurt at first, but the freedom is worth it. Others had to pay their lives for freedom and you only have to learn.

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Posted on 04-08-2006
Filed Under (Embedded) by esden

Yesterday and the day before Uwe and I were trying to flash an R8C and alternatively an M16C under Linux. We were finally successful using the Flasher from Thomas Fischl. You have to be careful to get the one on his site not the original from Lost In The Ether. The original seems to be somewhat broken.

Still there are some points you should be careful about. First of all the image you want to flash has to be for R8C or M16C respectively. The problem is that the addresses contained in the images have different order (endianes) depending on the chip. The sample srecord image contained in the tarball from Fischl is for _M16C_ and _NOT_ R8C.

Next thing is you should try to use a real hardware serial interface if you get problems with a serial to usb converter. We found out that even if the converter contains a prolific usb to serial chip it does not mean that it will work. We have two cables here and we know that Sitecom works.

We will probably write a patch for the flasher program containing some additional documentation and some checks and timeouts. The checks should validate the addresses one wants to flash are valid for the chip, and the program should timeout if it does not get data back from the chip during flashing. At least that is our TODO.

More information to come. ;)

[Update] Added some links.

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Posted on 28-07-2006
Filed Under (Comics) by esden

I just got pointed to a very very funny film, I have to share it with you immediately. ;) It is very well done and is really hilarious. You can see it here

Of course Channel Frederator also has very nice films in its videocast if you do not know it yet.

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Posted on 27-07-2006
Filed Under (ROCKLinux, Projects) by esden

Finally after many months of hard work ROCK Linux got a version bump to 3 and has many new and updated things to offer.

You can read the Changelog or simply download a Crystal build ISO or the sources.

Now you have to try it and start contributing. No?

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Posted on 24-07-2006
Filed Under (Life) by esden

Today I found a very nice article about $TOPIC. You can find it here.

Like most articles by Paul Graham it brings a lot of interesting light to the topic. If you ever considered yourself a nerd, or still are, you should for sure read it. It is based around the social dynamics in american schools but I think you can transfer many of the ideas to other countries and cultures.

Have fun reading.

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Posted on 20-07-2006
Filed Under (Uncategorized) by esden

If you are also in the same situation as myself and feel all tensed because of an exam … perhaps watching grass grow will calm down your nerves a bit.

Over some corners and edges of the internet I came to this “Watching Grass Grow” website.

(yes I know this post is the most useless till now but I had to share that with you)

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Posted on 17-07-2006
Filed Under (Lisp, Computerworld) by esden

Today I found something pretty nice a Lisp interpreter in Java Script.

I came to it through logowiki. I found it pretty amazing that you can run the example programs you have in your wiki. So I asked google about it.

The interpreter lacks some functionality like defun, defmacro and so on but I think it would be a nice base for creating logowiki like interpreter. I have not read the source yet but I think it may be a nice way to show someone how to create a simple lisp interpreter.

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Posted on 15-07-2006
Filed Under (Embedded, Lisp) by esden

I continued my reading about Lisp and also searched the Web a bit more for anything related to Embedded Systems. I think that this is a pretty sad story.

I heard from a friend that I missed ecls in my last post. He said that it is possible to compile Lisp to C with it and then you can crosscompile the resulting C source to any architecture you like. But that simply does not feel right. That is only a hack. You miss the things you want the most (beside Lisp itself) REPL and with it the integrated inspector and debugger just like the profiler and tracer. Also you miss binary upload of functions. Think for yourself. If you do not have that things does development with lisp feel like it should? If you ask me it does not.

So I searched further. I knew that there was someone who developed the triple L, Mars and Venus. I did not know what it exactly was but I knew that it was a lisp development environment for embedded systems.

Looking more in depth in to that, I had to realize that the only thing that exists is the paper L - A Common Lisp for Embedded Systems (pdf format is here) by Rodney A. Brooks and Charles Rosenberg. This paper is telling a beautiful story about a development system that would be the thing one would like to have. But you can not get it anywhere! On the page of Charles Rosenberg you find the pointer that the company IS Robots (that was developing L, Mars and Venus) is now iRobot (yes the Roomba guys). Searching their site does not say anything about lisp though.

The only other person bringing iRobot together with Lisp is Lemindor I have not read all his posts yet but he does not really say anything that helps me neither.

I also asked about the topic in #lisp on freenode but it seems that the overall opinion is that everyone is brewing his own Lisp if he/her wants to use lisp on embedded system.

That is really bad news. I was hoping that there will be something I will be able to base on. The only solution that I see now is to take some common lisp implementation and port it to some embedded system. And when it works start changing it and splitting in parts so that it fits development on embedded systems. (you do not really want the compiler on your embedded system normally an interpreter is enough)

That somehow sounds pretty big and heavy. :(

The second solution would be to start with a small Lisp implementation by oneself. When you read Paul Graham’s article Roots of Lisp you get the feeling that it can not be that hard. But still I think that is probably a false feeling. But if I had the power and money to hire some people that are bright enough I think I would attack that. I even know some people that are bright and that would be able to create such thing but none of them would want to invest their time in such a project when they do not get money for that. So there is high possibility that Lisp on embedded systems will remain a dream. :(

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Posted on 12-07-2006
Filed Under (Lisp, Studium) by esden

I had a very inspiring conversation today. I was trying to lay out why one should learn Lisp. I found that there are tons of reasons why Lisp is superior to other Languages. But I found some articles in the web that can explain that much better then me. There are some Articles written by Paul Graham that describe the reasons beautifully. For example “If Lisp is So Great” or “Revange of the Nerds“. I can only encourage you to read them.

What I found very interesting is the main statement of these Articles. Popularity of a Language is not the same as greatness as very well explained in the second Article. Another statement is that programming languages are slowly closing up with functionality and paradigms found in lisp. That is also one of the reasons why I started learning it, because I heard about that trend some time ago somewhere in the big depths of the net.

Most articles are stating that Lisp is the way to go to create web applications and financial systems. But I would even go further. I think it is also the way to go for embedded systems. Some people may think that Lisp is too big and too slow to use it for development on embedded systems. But look at your cellphone. It will probably have a JVM (Java Virtual Machine) running on it. What is that thing? It is a full emulation of a system. It runs bytecode. It is slow like hell but people still develop applications for cellphones compleatly written in java. I bet that there are phones that have their entire software written in Java. Now we look at Lisp. I found a comparison between JDK and SBCL here. It really seems that Java is faster and uses up less memory in most cases. At least taking a glimpse on the Graph. But as I already posted before. SBCL is not perfect. But there are developments like “Headless” coming that will better up that situation. On another site I found that the commercial Allegro Common Lisp implementation is the fastest. But sadly I do not see any benchmarks anywhere. And it does not support any embedded system.

I think that even if the benchmarks show that Lisp may be less efficient in speed and memory usage, it is only a matter of time and dedication to change that. But what do you buy with that loss of efficiency anyways. You get a REPL (you can interact with everything in the running program) you get binary upload (you can change the code of a running program) you get macros.

But for the beginning we could start with something more simple then the full fledged Common Lisp on embedded. There is still L (a Common Lisp language subset specially designed for embedded systems) and Mars realtime kernel to run L on. I sadly have not found a project site for that only a paper. I ask myself how much of Lisp goodness it provides.

Next semester I will have to make a project in embedded systems and the topic is not yet fully set. But I hope that I will be able to work towards the target of running lisp on embedded systems. I already asked my Professor about the idea and he is not negative but he still wants to talk about it. So wish me luck. (also I hope that my partners for the project will be willing to work in that direction too)

If you have any pointers and ideas about this topic then do not hesitate. I will appreciate any pointer.

[Update] Corrected minor stylistic mistakes.

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