Milan Zamazal's weblog

Thanks to the Icelandic volcano, I could experience a very special phenomenon yesterday: Clear and quiet sky. One would expect something opposite in relation to volcanic activity, but while there was no visually noticeable dust in the air (sunset was absolutely clear here without any colorful effects), air traffic over most of Europe was closed. So there were no jets flying over my head and I could enjoy completely clean blue sky and calm spring nature without the permanent noise coming from above.

I can't remember the last time when this happened to me, it's a very unusual event in the central Europe nowadays. Governments and newspapers count economic losses caused by the interrupted air traffic. But it's gain for me to experience beauty that has been lost with the so called advance. Good trick, Eyjafjallajökull.

I thought I should stop writing about stupid behavior on this weblog for a while but I can't resist. I've recently read an interesting article What DNS Is Not by Paul Vixie. It's about misusing the Domain Name System in ways that may look useful at the first glance but are actually harmful because their consequences were not properly thought of.

Well, we needn't delve into Internet protocols to observe lack of competence and poor behavior. Our everyday communication demonstrates it more than enough.

Who knows about the 72 character line breaking limit in e-mail messages today? Nobody educates common populace about the limit but even people who should be more knowledgeable don't respect it, as well as many e-mail clients that send such messages without warning the sender about common policy violation. This is simply arrogant to recipients. Perhaps the most common e-mail bad habit is citing the original e-mail at the bottom of reply to it. I read such replies as telling to me: "Dude, I didn't bother to respond to you in time so you probably don't remember why you've written to me and I don't expect you to archive your messages. As a courtesy from me, you can read your text after reading my words. I respond to various parts of your e-mail but my time is too valuable to bother with citing the corresponding parts, you the loser should find out yourself what I'm talking about, your original text is attached below after all."

Maybe this habit is somewhat related to chat conversions where citing the context makes little sense. Chat conversations also often demonstrate stupid behavior and lack of basic communication skills. A Jabber message comes from my colleague. He says: "Good morning.". After a while the next message arrives: "I need something from you.". Then the next surprising message informs me: "I think you could help me.". If I'm lucky, the next round of messages finally describes the issue. Only after I was uselessly disturbed prematurely and for several times, only because the messaging person doesn't understand the concept of message. And usually he additionally doesn't understand when to use on-line messaging and when to use e-mail.

People also often don't understand technical differences between different communication means. You can see it when people don't put spaces after sentences in e-mails or on the web. They use to save characters in SMS messages and don't figure out that other media may have different properties regarding readability and message size.

It's not just about stupidity and rudeness. Even intelligent and polite people may demonstrate some kinds of behavior described above. Why? I can see several reasons:

• Nobody educates us.
• We are exposed to uncivilized behavior and simply follow it.
• We don't care much as we are usually too busy to actually think and to get more than very shallow understanding of things that we should know better.
• The supposed experts such as communication client authors either lack the skills themselves (or they even invent new kinds of stupid behavior) or are unable to put guidance means to their software (or even guide users to behave in stupid ways).

Can we still hope for civilized digital communication or the September will never end?

I tried to make OpenVPN working in a Linux-VServer environment about a year ago. I couldn't find a straightforward HOWTO nor answers to all my questions. So I described what I had done and sent my questions to the VServer mailing list. I expected that I get answers to my questions and then other users trying to run OpenVPN with VServer can find fine instructions at least in the mailing list archives.

My mail has bounced because non-subscribers (I read most mailing list via Gmane NNTP gateway) were not allowed to post to the VServer mailing list. Considering my effort of writing the mail and the possible benefits of sending it I tried to temporarily subscribe so that I could send the mail. The subscription address didn't work. So I wrote to the postmaster about the problem but haven't received any answer. I got discouraged and gave up.

All the result was my wasted work of writing the mail and trying to send it. I made OpenVPN working some way and I haven't managed to return to my original problems to describe them on the wiki or so.

I really don't like closed mailing lists. Closing a mailing list is a cheap solution. You don't have to set up spam filtering. You won't get rants from readers about spam coming from the mailing list. And you annoy legitimate users and miss contributions.

Thanks to GNUBridge I could play a few games of contract bridge last weekend, for the first time since my student years!

There are areas where free software community fails. Not for technical reasons or lack of resources, but because of management and strategic planning incompetence.

Once I got an idea to get a Linux handheld. There were two models available at the time: Sharp Zaurus and Nokia tablet. The Nokia tablet didn't have any keyboard so I choose Sharp Zaurus, despite its worse operating system.

The preinstalled operating system on the Zaurus was some old version of Qtopia combined with proprietary applications. It had some nice features but many problems, such as missing Czech environment, limited set of applications, no X support and obsolete development environment. Some improved versions of the system were available but the basic limitations were still present.

After some time I replaced the original system with pdaXrom, a free Linux based operating system for PDAs. It offered X Window System and more modern development environment so it was possible to port common applications to it. Nevertheless pdaXrom was no way complete and its development has deceased during the time.

Developers of several free Linux PDA operating systems decided to join their efforts in the Ångström project. So I replaced abandoned pdaXrom with Ångström. But Ångström offered only very limited set of applications and I've never managed to get its development environment working.

There were only two options remaining: Either to put my Zaurus to a recycling center or to install Debian on it. Fortunately I could find a Debian installation for Zaurus so after several years I got chance to run a full featured operating system on the device. Finally I could install Emacs and other basic applications easily. But there were some minor problems and I've later upgraded to an up-to-date Debian version. By replacing the old preconfigured kdrive X server with standard xfbdev X server I've lost touch screen capability. So my Zaurus remains mostly unusable until I have time to look at the problem and can get it fixed.

I really don't understand why free software developers waste their limited resources by developing new operating systems that are unmaintained, very incomplete, missing good development environment and generally not perfectly working, when a good and complete operating system such as Debian already exists. All what was need was to customize Debian a bit for use on the particular kind of device. I could see the same mistake was repeated by Neo Freerunner developers. Instead of focusing only on important things like handling calls and SMS, they tried to maintain a complete operating system. In the final result Neo Freerunner didn't provide reliable calls nor a complete operating system.

Community developers have painfully failed in finding a feasible way of making a good free operating system for PDAs. Nokia managers made a better decision by deciding to base Maemo on Debian, thus avoiding a lot of useless work. I don't know whether Maemo allows easy porting Debian applications to it using a completely free SDK. If it does then it may be (the only) promising platform unless Nokia decides to stop its further development. Other platforms are either not well maintained, or are not actually free (Android with its proprietary SDK), or are based on a platform that can't run common free applications (Android, perhaps Symbian as well).

Several years ago I complained to a web shop web master about invalid character coding information in their web pages. I was told the invalid information was there intentionally so that the pages displayed correctly in a broken web browser which was used by 97% of their customers.

At another occasion I took seriously call for comments about the design of new web pages of another web shop. I complained that assuming particular screen size and resolution is not a good idea. I was told that most customers like these sizes and if it doesn't fit my environment well then I can use a web browser loupe.

Last years I've been wondering why most web sites use small font sizes, thus making the text poorly readable by default. I was told it is because common web browsers used to use large fonts by default and web masters started to compensate this by reducing font sizes on their sites. This approach became so common that not using it today might make the given site look bad. Hmm. I can set a minimum font size in my web browser configuration but then many web pages get broken because of their layout dependent on a particular font size.

Well, maybe the idiots are not present everywhere. How about sites of institutions full of computer scientists and presumably educated IT professionals? Do they know anything about solving problems at the right places?

Looking at the front page of my alma mater I can see they assume particular screen/window size and they reduce font size significantly. They provide a style for low vision users which stops assuming particular screen/window size but which still sets its own font size (perhaps low vision users can't set their own preferred font size because of all the web ignorance?). ACM pages don't presume screen size but they still set very small fonts. So no success here.

My last hope are highly skilled free projects. I'm looking at Linux, Debian, GNU and Wikipedia sites. With the exception of GNU (using fixed layout) all the sites look basically civilized. Such a relief! There is still a few competent web masters. But will they survive?

As many applications move to the Web, we are going to face another disaster. After the disaster caused by the dominance of the inferior desktop operating systems pushed by a single company we can expect flood of incompetence coming from all directions. It was difficult but still possible to resist a monopoly of a single company. But how to resist the global viral effect of "fixing" problems by introducing new ones?

Erik Naggum has died a month ago. This last action of him initiated another (hopefully the last one) naggumic flamewar on comp.lang.lisp. No surprise. His contributions, their value and his human behavior were discussed. For me, his major contribution remains his arguments about Common Lisp that enlightened me about that programming language. I discovered that Common Lisp is a powerful tool and not an unimportant obscurity as many mistakenly believe. Thanks, Erik!

I made my first small contributions to the OpenStreetMap project. I think making free maps is important and it's a lot of fun. When you buy or use a proprietary map, it's usually limited in its use, imperfect and you can't customize and improve it. A free project can change this.

My first impressions about OpenStreetMap in Czech Republic are positive. A lot of work has already been done on it and it contains a lot of data. It's still quite away from completeness of proprietary maps, many entities are missing and quality of data is variable. But we've already got reasonably complete data ready for further improvement. I think anybody can help a lot by improving areas he knows or visits, e.g. by adding missing tracks, names, points of interest and checking accuracy, correctness and completeness of current data. Great opportunity to spend a lot of time and fun outdoors, on trips and, of course, in front of a computer.

If you'd like to join, you should start with looking at OpenStreetMap Wiki.

We've got a daughter!

My old mobile phone becomes a bit unreliable, so I look for a new one. Perhaps a smart phone would be useful, but I'm not interested in proprietary and virus prone OSes without available source code and lacking good development tools and community support. Given these constraints there are at most two options: Google Android and Openmoko (Neo FreeRunner).

If I understand it right, Google Android is actually not an option. It's built on top of a Java platform and can be programmed only by using a proprietary SDK. So it's not completely free, I'm forced to work in Java and I can't port my favorite applications to it. No, thank you.

Openmoko is an interesting free software platform, but there are problems. Neo FreeRunner phone is relatively expensive while lacking some basic features commonly available in cheap phones (EDGE, camera). But the real problem is that it doesn't seem to provide robust telephony services instantly. I'm looking for a device which I can use exclusively, not for a supplementary and rather expensive toy. If the basic phone functionality worked without any problems then I might participate on development of other features. Hopefully Openmoko (or other nice platform) reaches that state before my next mobile phone will die.

So my next mobile phone will be a simple phone, smart phones haven't grown up enough yet to satisfy my needs.

It's very common: Someone claims and discusses a fact and makes conclusions from it without checking the fact first and without knowing its context. Even when it is easy to check and to get to understand. And with false facts one can prove anything, especially what he likes to prove.

Well, we all do mistakes. But in some situations people should be especially careful about what they say. We buy (certain) newspapers to get information. We pay scientists to provide new knowledge and competent advice to us. We expect informed decisions from statesmen. One can't check everything and everybody must rely on experts and reliable information channels. When this doesn't work, we get in troubles.

There is a lot of information available to us todays. Unfortunately much of it is false, often simply because someone doesn't know what he talks about and creates new, modified, bogus facts. The problem is this behavior is not limited to gossipers, even people who should be respectable and responsible sometimes show this ignorance. So do we get more information or actually less information today? And who profits from ignorance?

I've recently experienced root file system loss. This happened after my keyboard had stopped functioning due to a hardware problem and I had turned off the computer by the power button. Apparently some random process had happened on the disk and while most data survived the file system as a whole was seriously damaged and the system was unusable after fsck fixes. Well, I should probably use the reset button next time and turn the power off only in the bootloader menu.

I had to reinstall the whole computer. As Debian 5.0 was released recently, it was a good opportunity to test its installation.

The most interesting experience was discovering how software is unstable today. I often use development versions of the operating system so I use to be tolerant to various small problems. But when I install a released system from scratch, I expect a completely smooth process. It wasn't so and Debian 5.0 is disappointing to me. I don't think other distributions work better but Debian used to have higher standards (and I would expect them after 7 months of freeze). While the installation process itself was completely fine, not all of the installed systems were ready to work well without fixes.

There are two kinds of problems: Debian problems and upstream problems. I experienced one Debian problem. It was that apt-proxy didn't work in the default setup. This seems to be a known bug (!), making a small change in one of the source files was needed. Apparently there was some lack of coordination between archive maintainers, installer maintainers, and apt-proxy maintainers. Considering the complexity of the current distributions one can understand it's difficult to make them completely flawless. But there seem to be problems in testing and paying appropriate attention to reported bugs.

Upstream problems are more frequent and more difficult to deal with. The current trend seems to be to fix bugs by releasing new upstream versions without proper attention to regressions. Similarly, it's much easier for a distribution package maintainer to package a new upstream version than to backport the bug fixes. The result is that old bugs get fixed, but new ones are introduced. Combined with the facts that it's often uneasy to reproduce and diagnose the reported bugs and that we are all busy, busy, busy today, there is no obvious way to handle the general software instability problem. Even when some bugs are known, there's not enough power to fix them and they tend to get ignored.

So should we simply learn to live with the fact that software features get more and more complex while their stability gets more and more reduced? Or is there a feasible way to get the growing software complexity managed?

I think there are things worth to try. More and better interaction between software developers and users is needed. We need to build better ways to prevent regressions, to reduce amount of hidden bugs, and to offer easy means to users to determine causes of problems. Instead of hurrying for new features we should focus more on making existing functionality actually work. This is what I demand from the software as a user.

Unfortunately the real world doesn't allow me to step into this area anytime soon. But if I ever have opportunity to work more on Debian, I'll probably start with joining the Debian QA efforts.

Software patents make serious danger to all computer users, software developers and generally anybody who has something to do with computers and computing devices. I'm not going to elaborate on that topic here, you can find information about it e.g. on the web pages of Foundation for a Free Information Infrastructure. The important thing is that here in Europe we are in permanent danger of growing the software patent system into the full absurdity of the U.S. patent system. If we as E.U. citizens are not concerned and don't speak loudly then anything else will hardly stop the process. So please consider signing the Petition to stop software patents in Europe. Thank you.

There are people, creatures, objects, ideas, etc. we like and there are people, creatures, objects, ideas, etc. we don't like so much. There is basically nothing wrong with it. Those luckier of us can choose whether they prefer rice or potatoes for dinner today and that's fine.

The problem appears when we make and present opinions and judgements based on our preferences instead of objective facts. Proposing that rice is good and potatoes are evil or vice versa just because we like or dislike one or the other may look ridiculous. But condemning good or praising evil because we stand on some side is fatal. By making biased views we may hide truth, support lies and cause hurt of various impact. Prejudice is enemy of truth.

Perhaps we all are prone to making quick prejudiced conclusions. Just look around (and don't miss a mirror). Even intelligent and respectable people can demonstrate this syndrome. It's everywhere and it doesn't matter whether we look at matters of everyday life, personal relations, world changing ideas or purely technical things. It's often accompanied by incompetence, but these are two different things: One can make incompetent decisions while honestly trying to find the true way; biased approach is (less or more intentionally) built on false facts and thus bogus from the beginning.

We are sometimes afraid of truth for various reasons. But we can't change truth. Trying to do so makes no good and is futile. So let's try to be more honest and respectful next time.

There are two nice anniversaries in the end of this year. The first one was 50 years of Lisp and the second one is going to be 15 years of Linux on my desktop computers.

Lisp was the second (after FORTRAN) real higher level programming language. During the years Lisp has brought many important pioneering concepts to programming languages, some of them remain quite unique even today (e.g. the concept of little distinction between code and data). Lisp is a demonstration of competent (although not always perfect) approach to various problems in the area of programming and programming languages. And interesting things staying out of mainstream popularity gather interesting people. Lisp community is still full of smart and creative ideas. I hope I'll have opportunity to learn a lot there during the start of the next half of century.

Linux is the most popular free operating system kernel today. But 15 years ago it wasn't very easy to install and use free operating systems on desktop computers (thanks to Yenya for guiding me!). It required significant effort but it was completely worth of it. The experience of competent and working software under your control was great and unique, this is not something you can easily meet today. Such things combined with pioneering work leave permanent traces in a man. Unlike Lisp, Linux based operating systems achieved wide popularity and that have brought to them a lot of good and a lot of damage. Linux will never be again what it was in its early days. But it's still an interesting and powerful platform and I believe it survives the next 15 years in healthy state.

After very long time I've finally found how to make my two USB keyboards and mice accessible under constant file system names. Here is the trick:

ACTION!="add|change", GOTO="keymouse_end"
SUBSYSTEMS=="usb", ATTRS{bInterfaceClass}=="03", ATTRS{bInterfaceProtocol}=="01", ENV{ID_CLASS}="kbd"
KERNEL=="mouse*", SYSFS{idProduct}=="0067", SYSFS{idVendor}=="0458", SYMLINK+="input/mouse-genius"
KERNEL=="event*", SYSFS{idProduct}=="0067", SYSFS{idVendor}=="0458", ENV{ID_CLASS}=="kbd", SYMLINK+="input/keyboard-genius"
KERNEL=="mouse*", SYSFS{idProduct}=="071d", SYSFS{idVendor}=="045e", SYMLINK+="input/mouse-ms"
KERNEL=="event*", SYSFS{idProduct}=="071d", SYSFS{idVendor}=="045e", ENV{ID_CLASS}=="kbd", SYMLINK+="input/keyboard-ms"
LABEL="keymouse_end"

I can boot without manual assistance now!

I've always wondered how it is possible that Americans elected GWB president, even twice. I start to understand it after the recent elections in our country. Combination of irrational arguments, misleading promises, fear and odd faces makes the trick. Apparently it works everywhere.

Two years ago I filed a complaint against one of the worst Czech spammers, "Hotel u Lípy". Then nothing happened and I didn't expect too much, reading stories that those spammers exploit a loophole in Czech antispam law.

To my surprise I've received an answer from The Office for Personal Data Protection today. They notify me that they made inspection at the spammer's company and found breakage of the law by sending a business e-mail message without previous agreement of the recipient. As the result they punished the spammer with a financial penalty.

Well, I don't know whether the spammer's business has been punished significantly or not. But dealing with legal offices is definitely no pleasant thing and they would risk worse problems if they continued their spamming activities. And I'm glad enforcement of the antispam law actually works. Good news!

Enough is enough. Telefónica O2 has lost another customer and I hope this hasn't been the last one.

The company has annoyed me with their marketing practices for several years. Their dealers bother us at our home with offers we didn't ask for nor are interested in. Moreover those people are often just stupidly assertive idiots, the last example being a guy offering TV services without having any idea what terrestrial digital broadcasting is. This is accompanied by numerous phone calls trying to persuade us to switch to more expensive services. No other telecommunication company behaves this way here. The last straw was when they became almost successful to persuade my wife that she would save her money by switching from prepaid mobile phone service to a more expensive tariff. She would pay the same money or more for the same service and she would have to sign this deal for two years. I got angry and looked around. I've found O2 was right at least with one argument: The current prepaid service was unnecessarily expensive. Switching to another mobile phone operator, Vodafone, should save at least one third of the current spendings.

So we rejected the expensive offer and decided to leave O2. Our telecommunication law is civilized enough to allow switching to another operator while retaining the original phone number. In theory, it should be easy and fast, taking only a few days when leaving prepaid services. So we tried to do it.

The process starts with ordering phone number transfer (and services) from the new operator. We did this on some Tuesday. The next step is to send an SMS requesting the old operator to cancel the prepaid service and to free the phone number for the transfer, we did this on Thursday evening. According to national regulations the process should take at most 2 working hours to authorize (or deny) the request and another 5 working hours to free the number after successful authorization. So I expected the process should be finished during Friday. We received an immediate SMS confirmation of receiving the request. In the Friday morning we received a phone call from Telefónica O2 offering us benefits if we decide to remain with them. We rejected it and then nothing else happened. On Monday I called Vodafone asking them whether it's OK that nothing happened at O2 about the transfer. They told me the time limit to authorize the request is 5 working days. I think they were a bit incompetent, confusing monthly tariff services with prepaid services. But I waited for another day. Being doubtful about the process I called O2 on Tuesday asking them about the transfer status. They told me there is no transfer in progress and I should first send the cancellation SMS. My argument that we already had done it several days ago, its reception had been confirmed and we had received call from them offering us to stop the process was of no help. The lady on hotline was kind and perhaps really had no idea what happened. Well, mistakes can occur and I can understand that.

So on Tuesday evening we sent another cancellation request. This time we received several additional confirmations during Wednesday and the request was successfully authorized. It took more than two working hours but this time it at least succeeded and it was processed without excessive delay. But against my expectation the phone number hasn't been freed on Wednesday. Instead, we received an SMS offering us free credit of 300 Kč each month for half a year if we stop the transfer process. What a deal! Just before we decided to leave they had offered us that we should pay at least 300 Kč each month for two years. Well, who would take such a company seriously? So we ignored the offer and waited.

On Thursday we were leaving our country for a trip so I called O2 again and asked about the transfer status. They told me it was all right and they have 5 days to finish it. In my interpretation of the regulations it is just 5 working hours after successful authorization but I didn't waste my energy arguing with the hotline operator. I was already happy they haven't discarded our request this time.

We didn't receive any further notification from O2 but our mobile phone number was transferred and we successfully moved to Vodafone on the next Wednesday. Who knows, perhaps the transfer confirmation got lost as we were in roaming (but why?). If Vodafone chose the first possible day for the actual transfer, the phone number had been freed on Monday. So the whole process, which should take according to official regulations just one working day actually took about 7 working days.

I'd like to file a complaint to the regulation authority, but I'm afraid my record of the events is incomplete to trace it easily. But I can suggest you: 1. If you use O2 services, try to leave them. They might at least offer you a much better deal than when they attempted to suck more money from you. 2. If you decide to transfer your phone number from O2 to another operator, watch and record the process carefully. If it doesn't correspond to regulations, please complain to regulation authorities. According to various stories on Internet our experience with O2 is no way unique and complaining to authorities is probably the only way to force Telefónica O2 to behave properly.

Well, due to their horrible business politics Telefónica O2 has already lost 2 fixed lines and 2 SIM cards in our family during the last year. And I hope the process will continue -- let's pay our money to less arrogant phone operators.

I've been a satisfied eMusic customer for several years. Their interesting catalog providing unrestricted mp3 (even in the era of DRM madness) for reasonable subscription prices allowed me to find a lot of good music which I would have missed otherwise. About a month ago they notified me without further details that they no longer provide services in my area and that my subscription was cancelled. It was somewhat strange, but they were fair and refunded my whole year subscription.

Although I liked eMusic I don't regret it much. Nowadays there are other alternatives available, offering good music for reasonable prices and with standard selling model instead of the subscription service. So it's time to start spending money on music elsewhere. I'll start with picking my favorites from Indies Records and I'm also going to look at Magnatune. Any other tips for nice music mp3 shops?

I looked at a price list of PC CPUs after some time and wondered what AMD Phenom is. So I looked at the AMD website. To keep the story short I'll limit my experience to a single FAQ entry labeled "What is the AMD Phenom(TM) processor?", well representing overall information provided there.

The first part of the answer says: "AMD Phenom(TM) processors represent the next generation of AMD's award winning multi-core Direct Connect Architecture with AMD64 technology enabling greater memory throughput, lower latency and ultra-fast connections to system resources including graphics processors and accelerators." Well, so they say the new family of processors provides better performance than its predecessors. I wouldn't expect the opposite, so nothing new to me.

The next paragraph: "Featuring true quad-core technology, AMD Phenom(TM) processors are designed to deliver unprecedented megatasking performance and highly tuneable performance platforms to meet the demanding needs of technologically savvy enthusiasts." This paragraph is interesting because it contains the only single bit of information of the whole FAQ entry answer, i.e. that these processor are quad-core processors. But I could read this already in the price list. As for "unprecedented megatasking performance" and "highly tuneable performance platforms" I couldn't find anything indicating that it describes any real features so I suspect they are just marketing idle talks.

And finally: "AMD Phenom(TM) processors are designed for phenomenal performance and optimum energy efficiency for a growing list of demanding applications, including digital content creation, high-definition video editing, multi-threaded gaming and creative design. AMD Phenom(TM) processors are targeted toward mainstream users who crave more performance and productivity." I see, these processors are designed so that one can work with a computer. What a surprise!

So I still don't know what the Phenom thing is about. But I know now that either AMD are idiots or they have nothing great to say about this family of processors and they try to hide this fact in meaningless blurbs. In both cases I'd hesitate to buy AMD processors.

I decided to buy some chess books for the first time after many years. I'm going to start playing chess again, after several years long break. I think it might be a good step towards my mental recovery. I've been being busy with many dull activities last years and I haven't got much opportunity to employ analytical and logical thinking. Chess is great as it requires (except for its entertainment forms such as blitz) deep and careful thinking. Only then one can be rewarded with pleasant results while superficial approach may get punished very quickly, especially when playing against a computer. This is in big contrast to our common social environment that directs us to operate quickly, unreliably, in stupid ways and without understanding anything.

It's much easier to buy chess books now than it used to be the last time I was deeply interested in chess. Thanks to Internet shopping the choice of both new and used books is great and many interesting books became easily accessible. I bought the books from chessbookshop.com operated by a retired GM Karel Mokrý. I must say I was very satisfied with it and I can recommended that shop to chess lovers.

I've been using two monitors with two graphics cards on my computer for long time. I've got another spare old CRT monitor so why not to utilize it? I connected it to a free VGA port on one of the cards and started experiments.

Compared to the two independent graphics cards setup, using two monitors connected to a single card handling a single desktop was relatively easy. By default the monitors show the same screen. I tried to setup Xinerama but these attempts have always finished with X server segmentation faults. After some more searching I've found that the proper tool to use, other than Xinerama, is XRandR. I just had to upgrade the xrandr utility to a newer version. Then it was easy, using xrandr one can play with dual monitor setups on the fly, without needing to restart the X server (which is equal to reboot on my dual card machine). And StumpWM works great with XRandR, I had just to figure out that the second monitor screen is nothing else than another frame.

The only problem is that the whole XRandR setup is limited to the total possible graphics card resolution, 1920x1200 in my case. So the second monitor is limited to 640x480 resolution in my setup. But it's still well usable for tasks like watching TV while doing something else.

I've been a user of Microsoft products for some time now. No, I didn't install their operating system on my workstation of course. But I started to use their Natural Ergonomic Desktop 7000 wireless keyboard + mouse set.

When looking for an ergonomic wireless keyboard several months ago I've found that the Natural 7000 set is the only choice. Except for Microsoft, only Logitech offered split wireless keyboards, but they didn't manage to understand where the backslash key belongs to so it was no option for me.

Surprisingly this new Microsoft keyboard is based on the standard keyboard layout, with addition of some more or less useful keys. It fits into my hands very well and typing on it is more comfortable than on my old Chicony ergonomic keyboard. Its adjustable tilt looks like a good idea to me, I like it. It was just necessary to get use to the keyboard as it's somewhat different to my previous keyboard in its shape. I also had to get rid of my bad typing habits to use the keyboard well. I can't judge on real usefulness of the extra keys because they don't work with the latest Linux VServer kernel and I have to wait until VServer gets updated for the last Linux changes. My only complaint about the keys so far is that the multimedia keys look very cheaply built and feel like they could fall apart any time. But Microsoft offers three year warranty for the set so we'll see.

The mouse feels very well too. I think the side holding approach is a very good idea, it became relief for my hand after some time of its use. The mouse is nice to handle, it's just too sensitive for my taste (any way to get it change in X?). Some people complain the mouse is too heavy but for me it's completely fine. The side buttons are easy to reach for me (unlike for most people who reviewed the mouse on internet). There is one problem with the mouse: The left and right scroll wheel movement and especially clicking the scroll wheel (the middle button) are very though. I often have to press the middle button more than once before it actually clicks. I don't know whether this is a feature or a problem of my particular mouse.

It's necessary to note that my hands and fingers are longer than average and that people with smaller hands may feel both the keyboard and mouse uncomfortable.

I can't say much about the operating range of the keyboard and mouse as I use them very near to the receiver. I tried to type something and handle the mouse at several places about 5 meters away from the receiver including one thick wall in between and it seemed to work well as long as there was no special obstacles in the way, as a computer case or my body.

As for the power source I put some old NiMH accumulators to both the keyboard and mouse. They last for about 1-2 months in the keyboard and for about twice as long in the mouse (note I use a keyboard much more than a mouse). Although both the devices are equipped with low battery warning lights, they appeared to be useless. For the first time when the accumulaters got exhausted the keyboard suddenly stopped work in the middle of typing, the same happened later to the mouse. The next time the keyboard light just blinked shortly three times and the keyboard stopped work immediately after that. Perhaps it would work better with alkaline batteries, I don't know.

Overall I'm pretty satisfied with the set despite its minor annoyances. It's really ergonomic and well usable and this is what matters for me.

Sometimes the possible consequences of connecting old flashes to modern electronic cameras (both digital and film) through hot shoe are discussed. The problem is high voltage (up to at least 300 V) of those flash units on their contacts, exceeding the standard limit of 12 V. I've never heard about a destroyed camera from direct user experience, but people are warned not to try such things.

What's my own experience? An old simple hot shoe flash with voltage about 90 V on its contacts usually worked with my Pentax MZ-M camera, but I sometimes experienced delayed mirror return (for about half a second) after taking a snapshot. I was more cautious with my other body, Pentax Z-1, reported to be sensitive to high voltages. I once attached another flash unit, 40 V, to it. Two snapshots went fine, but on the third one it actually happened what the rumors had warned about: the camera got completely frozen and I had to remove the battery from it to get it alive again. However no other damage has happened.

I no longer risk damaging my cameras by using old flash units. I bought a used Pentax flash unit for €15, with safe voltage. It is only a bit stronger than common built-in flashes, it doesn't have any TTL etc., but it works, it's safe, cheap, small, light, inconspicuous and communicates with the Pentax cameras. It's enough for my occasional flash use.

This is my warning to other photo amateurs: Although no permanent damage has happened to my cameras, I can confirm that using old flashes with voltage higher than 12 V on their contacts may cause at least temporary malfunctions. And it's not true that Pentax cameras are safe up to 600 V.

Some time ago I've finally managed to get my Epson R220 printer somewhat calibrated. Standard Gutenprint drivers suffer from strong green cast on this printer and I wasn't successful to get it corrected directly in Gutenprint. Trying to play with the driver color settings has led me only to other problems, replacing one kind of color cast with a different one. Much better than standard settings but still not always usable. So the only way to print photos on my printer was performing printer color calibration. How did I do it?

First I installed Argyll color management system. It's not included in Debian (I guess not many people perform color calibration regularly and they are scared of irregularly maintained software with lots of possible problems) but it can be compiled and run easily. It's just not easy to use it. But it contains complete documentation, so with enough time, patience, ink, and paper it's possible to get the desired results. I didn't have enough time during last year so it took me more than one year, but it seems to work now.

The first step was to calibrate my desktop scanner. This was necessary to scan the printed samples for calibration processing. I ordered a scanner color calibration target from Wolf Faust and followed instructions from Argyll documentation. This step was relatively easy and I got my scanner calibrated soon.

The next step was significantly harder. When I tried to generate color patches for my 6-color ink printer Argyll created just greyscale patches. I didn't understand it, although the Gutenprint driver apparently uses inks other than black even on greyscale images (as long as color printing is enabled), I decided not to go this way. So I generated and used patches for an RGB printer. Yes, it's probably completely wrong from the point of serious calibration, but it basically works. First I tried to generate the patches for the target 10x15 media but the number of the patches on this area was too small and the calibration results were bad. I didn't have a larger piece of paper of this kind so I used a different kind of paper in A4 size. Professionals would probably fall faint reading this but I wasn't willing to spend another €15 for paper in order to print our family photos perfectly. Then I had to scan the printed results and to process them with Argyll. The process was smooth once I had managed to use proper commands with proper arguments and proper use of the srgb.icm file (taken from digiKam).

The final step was setting the color profile in PhotoPrint. This was easy and worked very well.

Of course my calibration process had several serious flaws: I used a desktop scanner instead of a proper measurement tool, I generated color patches for another kind of printer and I used different kinds of paper for calibration and printing. But the results are still better than any of my previous attempts of manual adjustments. They are not perfect, but my old digital camera is not either, not mentioning my uncalibrated monitor. And I'm glad that faces on the printed photos are no longer green nor violet. This makes my family satisfied enough :-), so this poor man color calibration fulfilled its purpose.

I've recently read an article from The Economist newspaper (reprinted in a Czech newspaper) about global positive changes of the world. Let's look at some arguments presented in the beginning of the article.

They say that number of people with income of one dollar per day or less has strongly decreased in China during the last 25 years. No mention whether the "one dollar per day" is just a term for a standard comparable unit of what you can buy for your basic living or whether it should be taken as actual monetary income and thus it doesn't say anything because what you could buy for one dollar in (different areas of) China 25 years ago and what you can buy for it now is likely to be very different.

Another argument was that the number of children dying before the age of 5 has decreased by one quarter worldwide since 1990. As I don't have any idea how many small children survived, I don't know whether the decrease was achieved by improvement of health care, living conditions, etc. or perhaps just by reduced birth rate. Neither I understand why global changes are once demonstrated by data from China and next time by worldwide data.

I didn't bother to read the rest of the article. Improper use of relative and absolute numbers and careless mixing of different sources is either ignorance or manipulation. The article was an excellent demonstration of the saying that with enough statistical data you can prove anything. This doesn't necessarily mean the conclusions are wrong, they are just based on void inputs; whatever they would say and conclude could be "proven" using such methods.

The shame is such a stupid article could be printed in a media which are probably willing to be taken seriously. It reminds us that we should be careful about all inputs and conclusions presented in newspapers.

About once a year I manage to attend a live music show. This year I've chosen Autopilote (Fajt, Smeykal, Yumiko, Holý, Václavek). I watched them in Noc s Andělem on TV a few weeks ago and I liked the music, thinking it might be nice to listen to it live. This opportunity came yesterday and the concert was great, incomparable to what I could previously hear on TV. For me the music is catching and original, I've never heard something like this, it just evokes (not surprisingly) some Brno roots. Recommended.

We have moved from qmail to Exim recently on our company mail server. It is a big relief. The mail server can handle the high amount of incoming junk mail now, it is reasonably manageable and provides readable logs.

It was late transfer. It is not easy to move a mail server to a completely different software and it happened only after more significant qmail problems than just a weird licensing conditions arose. But the important question is: What are the lessons?

Many years ago I was enthusiastic about qmail myself. In comparison to its common alternatives of the time, Sendmail and Smail, qmail was innovative and elegant. I only became a bit reserved about it when Debian Free Software Guidelines explicitly excluded qmail from Debian (there is a special item in the document inspired directly by qmail licensing problems) and djb (the qmail author) became well known for his poor communication style. The time has proved these issues were important and I stopped using qmail on my machines. Now, many years later when qmail is semi-dead and we can look backwards, I can identify three major lessons from the qmail rise and fall.

The first lesson: Beware of non-free software of any kind. Although qmail original license didn't prevent modifications and their distribution, it was restrictive enough to prevent unlimited spread of the software and it put obstacles to contributors and users. In the final result qmail was unable to adapt to new conditions appropriately, namely it is incapable to handle junk mail. Although djb put qmail to public domain recently, it was too late, as with many other pieces of dying non-free software (but it may be still better than to let the software die completely).

The second lesson: Software can't be completely separated from its author. If he is blinded by his pride, numerous problems can appear. For instance the semi-restrictive qmail licensing conditions served no good, they were designed just to satisfy author's ego. Completely ignoring compatibility with other similar software makes adoption of new ideas more difficult. Telling other people they are idiots (either explicitly or implicitly) discourages contributors, doesn't educate the users and builds a wall around the author preventing him from considering other opinions and correcting his wrong decisions. In the final result the software can't utilize its full possibilities and it degrades.

The third lesson: Security is a more complex concept than just avoiding privilege escalation and buffer overflows. Empty security advisory track may look nice but what is it good for when the mail server gets permanently irresponsive under junk mail floods, distributes junk mail itself through bounces and one has to apply third party patches not covered by the security warranty? In such a case the security statement is mostly just a blurb without connection to reality.

Why did I select Exim as the new MTA on our company server? Two mainstream good MTAs today are Exim and Postfix, they are mostly comparable and both the Exim and Postfix communities talk with respect about each other. So as a matter of personal preference I selected Exim which was already known to me.

Amazon is going to sell their new e-book reader. Sure, I wouldn't buy a proprietary device that serves as a purchase tool for a particular seller. But a more interesting thing is that they advertise access to Wikipedia several times in their blurbs.

I'm curious whether Amazon is going to support Wikipedia, e.g. by donating some reasonable amount of money for each e-book reader they sell, or whether they are just parasites who misuse a free project financed by someone else. I already boycott Amazon because of their dirty business practices (using software and business method patents to beat their competitors). But if they use Wikipedia to market their products without supporting the project (and I guess they would proudly tell us if they supported it) then it's another reason to avoid buying anything from them. So does anybody know something about any Amazon and Wikipedia relationship?

BTW, one positive result of this issue is that it reminded me I should donate to Wikimedia Foundation during its current fundraising campaign.

Film scanners are often claimed to be superior to flatbed scanners when scanning 35 mm films. The harder thing is to find actual facts supporting such claims. Actually it's possible to find samples suggesting there is no significant difference between the scanners. And even Minolta was able to find the only relevant argument for film scanner superiority on their site: better optics.

The fact is that I was sometimes dissatisfied with a cheap flatbed Epson Perfection 2480 Photo scanner. I can compare its outputs with a dedicated film scanner (Nikon LS-40 / Coolscan IV) now. Indeed, there are significant differences in the results.

As for image quality I could observe the following:

• Every film defect (scratches, dust, garbage) is clearly visible in Nikon scans. Without digital ICE the Nikon scanner would be almost unusable. Epson is much better in this area and thus it's the only option for scanning my old b&w negatives.
• The true resolution of the Nikon scanner is clearly superior to the Epson, despite their nominal resolutions are almost the same (2900 versus 2400 ppi).
• Nikon is much less prone to grain aliasing.
• Nikon output can be used without further processing, sometimes small level of USM improves the image. Epson output is very soft and typically requires strong USM followed by noise reduction and additional USM to get well looking results (but still somewhat inferior to unprocessed Nikon output).
• Epson suffers from irregular annoying stripes in monotone image areas, in the direction of scanning. This is one of the worst and completely unavoidable problems of the scanner.
• Nikon has shallow depth of field and the scan is often sharp in the center (the default focus point) and unsharp near the film field borders. Special care is needed to reduce the effect. Epson is much better in this area.
• Epson poor film holders make the scans prone to terrible reddish artifacts near the both ends of film stripes.
• There seems to be no relevant difference in the dynamic range capabilities of the scanners when scanning negatives.

To summarize: While one can often receive similar results from the scanners, there are situations where only the film scanner is able to produce good results. IMHO it's really worth to consider investment into a dedicated film scanner instead of a cheap flatbed. On the other hand the flatbed scanner may be superior when scanning imperfect films when digital ICE can't be used.

Besides the image quality convenience may also matter:

• Epson is much faster, I'd say I can scan a roll of film with it twice as faster than with Nikon.
• Nikon can load film stripes itself (some flatbeds can do that too). On the other hand it's sometimes difficult to force it to move the film field to the desirable position so that it could be scanned whole, without cutting out any part of the film field area. I don't know whether this is a problem of the scanner or of something else (driver? user?), but it's annoying.

And finally, which low-end film scanner to buy? The cheap film scanners such as Plustek or Reflecta don't seem to provide quality comparable to standard middle-range film scanners. A used Nikon LS-40 / Coolscan IV seems to offer very nice quality/price ratio for an advanced amateur. Older Nikons are SCSI devices, i.e. quite inconvenient to use with contemporary personal computers. Nikon LS-50 / Coolscan V is one of the rare middle-range film scanner models still in production. Minolta Dual scanners are cheap, but they don't have Digital ICE (which makes their use very inconvenient), they seem to be more prone to grain aliasing and they are infamous for banding problems. If I understand the technology right, Nikon scanners are superior in their LED light source: It's very reliable and there is no color interpolation (each pixel is scanned in all the color channels separately). Minolta Elite 5400 scanners look very nice but they are more expensive and the II model is known to be prone to defects. I don't care about Canon scanners as they are completely unsupported in SANE. As for SANE support, AFAIK only Nikon LS-30 and LS-40 and Minolta Dual II and III are reported to be fully supported.

HTH, although it's all mostly a personal opinion of course.

Mike Oldfield's Incantations is a nice piece of music to listen to during hot summer days. Like many Oldfield works, it may not sound that great on the first (maybe also second or third) listening ("huh, who would like to listen to all the long repetitions?") but then, as aptly expressed by someone on the net, it falls on you. I've listened to this last of the initial great Oldfield's works many times through the last years and it has never bored me. So if you can find opportunity to spend an hour and a quarter at a calm place without being disrupted, you can try to enjoy the repetitive patterns of Incantations.

Well, I switch the revision control system I use for the third time during last years.

When I decided to try something else than CVS, I started with GNU arch. This was a good choice as GNU arch made a good basis of modern free software revision control systems. Unfortunately problems in GNU arch development and its split into unconvincing forks and replacements forced me to look elsewhere.

There were several reasonable choices among distributed revision control systems: darcs, Mercurial and git. I switched to darcs as it looked simple, user friendly and was popular among Lisp programmers. Indeed, as long as darcs is used for a single line development (as is typical with Lisp projects because they usually don't require much development power) it works very well. I was very satisfied with it until I have been hit by the infamous darcs performance problem. This is a fatal drawback preventing use of the revision control system at all in certain situations. So I had to switch to another system once again.

The remaining choices were Mercurial and git. I decided to go git as it looked more reliable to me (something used for Linux kernel development is unlikely to be seriously buggy or suffering from performance problems, isn't it) and provided "native" tools for cooperation with CVS (this is important to me as I usually work on projects with upstream CVS repositories).

I've been using git for several months now and I'm satisfied with it. From the user's point of view it's somewhat ugly and unfriendly, but one can live with it using a few external tools such as Emacs and qgit. More important is that the underlying concepts look right. Also the git CVS cooperation tools work better than tailor that the other systems use. I think git future is promising, git seems to be well founded, with stable development and growing user base (I know I'm not the only one migrating through the systems as described above and being now a git user). Perhaps git is the future leading free revision control system and I won't have to migrate again in the next years.

Sharp Zaurus SL-C1000 is shipped with its own Linux operating system based on Qtopia. The system is not bad, it is stable and although it requires some updates to become really usable, it provides nice PDA environment covering many areas of use. But it suffers of some problems: it's incompatible (as it uses Qtopia instead of X), contains a lot of proprietary applications and the available development environment is obsolete. Simply said it's difficult and annoying to port applications to the system.

So I decided to replace the Sharp operating system with pdaXrom, which is a free X-based operating system for (Sharp) PDAs. They say the operating system replacement should be safe as the Zaurus low-level system service menu is placed in ROM and can't be erased. First I tried to install the latest pdaXrom release, i.e. 1.1.0r121. This was a mistake as the device ended up seemingly completely dead after reboot. It took me a lot of googling and experiments to get it recovered and to install pdaXrom 1.1.0beta3 which seems to work fine so far.

The first advice: Don't install the latest 1.1.0r121 release, install 1.1.0beta3 instead (until some new stable version is released) which has reputation of being relatively stable.

The second advice: If you end up with a "dead" C1000, you can recover it as described on the TRIsoft site. But there is an important missing detail there: You need to press Fn+D+M to start the service menu, not only D+M.

One of the main advantages of digital photography over film is that all the process is in your hands. With film at least its development is usually left to a laboratory. And this is a problem, I've experienced a lot of troubles with it: scratches, sticked garbage, fingerprints, even exchanging my roll of film with one of another customer. In the better case I can partially repair some of the damages spending a lot of time on retouching, in the worse case the shot is lost. I'm not a photographer who takes a lot of pictures and then chooses a few pictures from a roll of film, I usually spend significant amount of time on taking each shot and don't shoot the same picture twice. So if they damage my shot, it's completely lost.

I don't want to risk those problems anymore. As I don't know how to find a good laboratory in Brno, I have two alternatives. Either sending my films for development to PHOTO life's CREATIVE LAB (they claim they handle everything in the process very carefully) or developing the films myself. With my low-volume production I'll probably try the first choice. It means about 3 € extra cost for postage, but it still looks like the cheapest way to get the thing done right.

BTW the laboratories in Brno that show complete incompetence are Fosh foto and Fotex (at Kobližná).

My first X Window workstation ran pretty will with just 8 MB RAM. Nowadays even 2 GB RAM (i.e. 256 times as much) is not enough for personal use. My workstation runs 24/7, so I sometimes check what consumes all the memory capacity. I can usually identify the following processes being the cause:

• Firefox 2. When I upgraded to it from 1.5 I was happy my web browser didn't crash anymore. But there's another problem with it: it can easily consume up to several hundreds MB of RAM, so it has to be restarted from time to time. This is the most embarrassing case, the flagship free web browser is a memory hog even after so long time of its development .
• Vlc serving my DVB-T card. The vlc server gets sometimes completely crazy and starts consuming a lot of CPU time and memory. This is the most dangerous case because it can put the computer out of normal operation if the vlc process is not restricted.
• Some Xfce applets. There are clearly memory leaks in them. Well, unlike GNOME panel and applets, Xfce applets work as expected otherwise.
• Amarok audio player. I really don't understand why an audio player needs more than 100 MB of memory.

I've recently listened to (), the untitled album, by Sigur Rós. It's an interesting piece of music. I can't say much about it, try listening to it yourself.

I've recently looked for free software related to civil engineering. To my surprise there is probably not any. There are several projects that could potentially be used in civil engineering but none of them is directly usable for that purpose. For example 2D drawing tools may be good enough for electrical or mechanical engineering but do not provide means required for drawing construction plans.

Perhaps most people working in the area of civil engineering have some access to professional tools and that is all they need. If your needs are different and you miss civil engineering free software, let me know.

I don't understand why webshops put so much effort into making buying goods in them more difficult. My favorite hardware shop used to be ALFA COMPUTER, one of the reasons I liked them being their simple and well arranged web pages. That's gone now. They've recently introduced new web pages. The worst thing in them is heavy use of tables and pixel based dimensions. This results in a garbled screen unless a user uses particular screen resolution or is willing to destroy his eyes by reading 7-10 pixel characters on a 1280x1024 monitor.

I complained to the webmaster and he kindly explained me that using pixel based sizes is necessary to get the look "right" and that I can use a magnifier web browser function if I can't read the small font. As most users like the new pages, I gave up. Although I usually buy hardware in real shops, I actually choose it in the corresponding webshops first. As this is no longer easily possible for me with ALFA COMPUTER, they've lost a customer.

Looking over other hardware web shops here I can see such a stupid approach to making web pages is no way unique. And this is not the first time I switched to another hardware seller because of broken web pages. It must be some crowd effect that motivates webshops to make slow, unreadable and confused web pages that take customers away. BTW, any good hardware seller recommended?

Scanning software should deliver maximum information in the best possible form. It's not necessary to avoid further processing, but it's important to keep it possible and to perform processing steps that can be made automatically without losing important information. Choosing right scanning tools is important as mistakes in this process may result in the necessity of repeated scanning and processing. How is it with scanning negative films on Epson Perfection 2480 Photo?

The original Epson scanning software on Windows usually produces good results, but one must be careful to actually receive them. Obvious selections are setting colors to 48-bit (or 16-bit in case of bw negatives) and resolution to 2400. "Improvement" options should be all disabled, especially dust removal that in my experience actually doesn't remove any dust but removes many details instead (this is a pure software algorithm, the hardware doesn't support any dust removal features). Note that unsharp masking has to be disabled for each scanned film field individually. When you forget it, you receive bad results when you try to apply unsharp masking later yourself. Usually the software produces good colors (better than I'm able to get from the negative by other means now) although manual corrections are often necessary during post-processing, as is common with color negatives. It happened to me once with a few strongly overexposed film fields that the software has chosen very aggressive color clipping and I had to adjust histogram settings and rescan the given fields again. The Epson software requires a lot of mouse clicks (on average more than 2 for each scanned field) and suffers from memory leaks, requiring occasional restarts.

On Linux the scanning process is more challenging. The SANE driver supports all the crucial hardware features and scanning half a film strip requires just a single scanner button press (when you use scanbuttond) and no mouse clicks. But here is a small 1:1 sample of what you receive (contrast is much increased in all the examples to demonstrate the problems more clearly):

Note two things:

1. The very ugly stripe about one quarter from the left in the image. This is not a scratch on the film, this is a systematic defect.
2. The regular pattern of vertical one pixel wide darker and brighter stripes around edges of dark areas.

As for the special ugly stripe, it helps turning quality settings off (i.e. removing the '--high-quality=yes --quality-cal=yes' scanimage command line options). I guess their meaning is reversed in the driver by mistake. So here is new result:

The extra stripe is gone, but the regular stripe pattern is still there. I've no idea why it's there but I've seen something similar in the samples from other scanners on the net so it's likely to be some common hardware feature. FWIW, scanning direction is vertical here. No such apparent stripes are present when the same image is scanned with the Epson software on Windows:

So I tried to get rid of the stripes by averaging each two neighboring stripes into a new "neutral" stripe. This operation shouldn't lower resolution of the image, it may just soften it (and the actual scanner resolution doesn't correspond to the scanned image size anyway). So it should be safe. Here is what I received after applying the following imagemagick commands:

convert -crop 199x158+0+0 image.png crop1.png
convert -crop 199x158+1+0 image.png crop2.png
composite -blend 50% crop1.png crop2.png result.png

I think the result is pretty close (except for contrast adjustments) to what Epson software produces, so it's probably the way to go.

All the things presented here may look clear and simple. But it took me long time coming from the first naive scanning attempts to discovering why the scanned images don't look well and finally finding out all what's described above. Now I know supporting a piece of hardware doesn't mean just providing raw low-level drivers to the hardware. The hardware specific post-processing part is also very important and the user may receive poor results if this part is missing.