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<channel>
<title>Milan Zamazal's blog   </title>
<link>http://weblog.zamazal.org</link>
<description>Milan Zamazal's blog</description>
<language>en</language>
<item>
  <title>Another udev discovery</title>
  <link>http://weblog.zamazal.org/udev2.html</link>
  <description><![CDATA[

<div class="document">
<p>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:</p>
<pre class="literal-block">
ACTION!=&quot;add|change&quot;, GOTO=&quot;keymouse_end&quot;
SUBSYSTEMS==&quot;usb&quot;, ATTRS{bInterfaceClass}==&quot;03&quot;, ATTRS{bInterfaceProtocol}==&quot;01&quot;, ENV{ID_CLASS}=&quot;kbd&quot;
KERNEL==&quot;mouse*&quot;, SYSFS{idProduct}==&quot;0067&quot;, SYSFS{idVendor}==&quot;0458&quot;, SYMLINK+=&quot;input/mouse-genius&quot;
KERNEL==&quot;event*&quot;, SYSFS{idProduct}==&quot;0067&quot;, SYSFS{idVendor}==&quot;0458&quot;, ENV{ID_CLASS}==&quot;kbd&quot;, SYMLINK+=&quot;input/keyboard-genius&quot;
KERNEL==&quot;mouse*&quot;, SYSFS{idProduct}==&quot;071d&quot;, SYSFS{idVendor}==&quot;045e&quot;, SYMLINK+=&quot;input/mouse-ms&quot;
KERNEL==&quot;event*&quot;, SYSFS{idProduct}==&quot;071d&quot;, SYSFS{idVendor}==&quot;045e&quot;, ENV{ID_CLASS}==&quot;kbd&quot;, SYMLINK+=&quot;input/keyboard-ms&quot;
LABEL=&quot;keymouse_end&quot;
</pre>
<p>I can boot without manual assistance now!</p>
</div>

]]></description>
</item>

<item>
  <title>How to get elected</title>
  <link>http://weblog.zamazal.org/elections2008.html</link>
  <description><![CDATA[

<div class="document">
<p>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.</p>
</div>

]]></description>
</item>

<item>
  <title>Small victory against spammers</title>
  <link>http://weblog.zamazal.org/czech-spammers-victory.html</link>
  <description><![CDATA[

<div class="document">
<p>Two years ago <a class="reference" href="http://weblog.zamazal.org/czech-spammers.html">I filed a complaint</a> against one of the worst Czech spammers,
&quot;Hotel u Lípy&quot;.  Then nothing happened and I didn't expect too much, reading
stories that those spammers exploit a loophole in Czech antispam law.</p>
<p>To my surprise I've received an answer from <a class="reference" href="http://www.uoou.cz">The Office for Personal Data
Protection</a> 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.</p>
<p>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!</p>
</div>

]]></description>
</item>

<item>
  <title>Phone number transfer</title>
  <link>http://weblog.zamazal.org/bye-o2.html</link>
  <description><![CDATA[

<div class="document">
<p>Enough is enough.  Telefónica O2 has lost another customer and I hope this
hasn't been the last one.</p>
<p>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.</p>
<p>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.</p>
<p>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
<a class="reference" href="http://www.ctu.cz/1/download/OOP/Rok_2007/OOP_10_uplne_zneni_31_01_2007.pdf">national regulations</a> 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.</p>
<p>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 <em>free credit of 300 Kč</em> each month for <em>half a
year</em> if we stop the transfer process.  What a deal!  Just before we decided to
leave they had offered us that <em>we</em> should <em>pay at least 300 Kč</em> each month for
<em>two years</em>.  Well, who would take such a company seriously?  So we ignored the
offer and waited.</p>
<p>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.</p>
<p>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.</p>
<p>I'd like to file a complaint to the <a class="reference" href="http://www.ctu.cz">regulation authority</a>, 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.</p>
<p>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.</p>
</div>

]]></description>
</item>

<item>
  <title>eMusic gone</title>
  <link>http://weblog.zamazal.org/emusic.html</link>
  <description><![CDATA[

<div class="document">
<p>I've been a satisfied <a class="reference" href="http://www.emusic.com">eMusic</a> 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.</p>
<p>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 <a class="reference" href="http://www.indies.eu">Indies Records</a> and I'm also going to look at <a class="reference" href="http://www.magnatune.com">Magnatune</a>.  Any other
tips for nice music mp3 shops?</p>
</div>

]]></description>
</item>

<item>
  <title>Are AMD processors of any worth?</title>
  <link>http://weblog.zamazal.org/amd-phenom.html</link>
  <description><![CDATA[

<div class="document">
<p>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 <em>&quot;What is the AMD Phenom(TM)
processor?&quot;</em>, well representing overall information provided there.</p>
<p>The first part of the answer says: <em>&quot;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.&quot;</em> 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.</p>
<p>The next paragraph: <em>&quot;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.&quot;</em> 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 &quot;unprecedented megatasking performance&quot; and
&quot;highly tuneable performance platforms&quot; I couldn't find anything indicating
that it describes any real features so I suspect they are just marketing idle
talks.</p>
<p>And finally: <em>&quot;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.&quot;</em>
I see, these processors are designed so that one can work with a computer.
What a surprise!</p>
<p>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.</p>
</div>

]]></description>
</item>

<item>
  <title>chessbookshop.com</title>
  <link>http://weblog.zamazal.org/chessbookshop.html</link>
  <description><![CDATA[

<div class="document">
<p>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.</p>
<p>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 <a class="reference" href="http://www.chessbookshop.com">chessbookshop.com</a> 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.</p>
</div>

]]></description>
</item>

<item>
  <title>Using three monitors</title>
  <link>http://weblog.zamazal.org/3-monitors.html</link>
  <description><![CDATA[

<div class="document">
<p>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.</p>
<p>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 <a class="reference" href="http://en.wikipedia.org/wiki/Xinerama">Xinerama</a> 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 <a class="reference" href="http://www.x.org/wiki/Projects/XRandR">XRandR</a>.  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 <a class="reference" href="http://www.nongnu.org/stumpwm/">StumpWM</a> works great with XRandR, I had just
to figure out that the second monitor screen is nothing else than another
frame.</p>
<p>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.</p>
</div>

]]></description>
</item>

<item>
  <title>Microsoft user</title>
  <link>http://weblog.zamazal.org/microsoft-user.html</link>
  <description><![CDATA[

<div class="document">
<p>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
<a class="reference" href="http://www.microsoft.com/hardware/mouseandkeyboard/productdetails.aspx?pid=095">Natural Ergonomic Desktop 7000</a> wireless keyboard + mouse set.</p>
<p>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.</p>
<p>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.</p>
<p>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.</p>
<p>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.</p>
<p>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.</p>
<p>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.</p>
<p>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.</p>
</div>

]]></description>
</item>

<item>
  <title>Is it safe to use old flashes on modern cameras?</title>
  <link>http://weblog.zamazal.org/old-flashes.html</link>
  <description><![CDATA[

<div class="document">
<p>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.</p>
<p>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.</p>
<p>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.</p>
<p>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.</p>
</div>

]]></description>
</item>

<item>
  <title>Printer calibration</title>
  <link>http://weblog.zamazal.org/printer-calibration.html</link>
  <description><![CDATA[

<div class="document">
<p>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?</p>
<p>First I installed <a class="reference" href="http://www.argyllcms.com/">Argyll</a> 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.</p>
<p>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 <a class="reference" href="http://www.targets.coloraid.de/">Wolf Faust</a> and followed instructions from Argyll
documentation.  This step was relatively easy and I got my scanner calibrated
soon.</p>
<p>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).</p>
<p>The final step was setting the color profile in <a class="reference" href="http://www.blackfiveservices.co.uk/photoprint.shtml">PhotoPrint</a>.  This was easy
and worked very well.</p>
<p>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.</p>
</div>

]]></description>
</item>

<item>
  <title>Can we take The Economist seriously?</title>
  <link>http://weblog.zamazal.org/the-economist.html</link>
  <description><![CDATA[

<div class="document">
<p>I've recently read an article from <a class="reference" href="http://www.economist.com">The Economist</a> 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.</p>
<p>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
&quot;one dollar per day&quot; 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.</p>
<p>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 <em>survived</em>, 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.</p>
<p>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 &quot;proven&quot; using such methods.</p>
<p>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.</p>
</div>

]]></description>
</item>

<item>
  <title>Autopilote</title>
  <link>http://weblog.zamazal.org/autopilote.html</link>
  <description><![CDATA[

<div class="document">
<p>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&nbsp;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.</p>
</div>

]]></description>
</item>

<item>
  <title>From qmail to Exim</title>
  <link>http://weblog.zamazal.org/qmail-exim.html</link>
  <description><![CDATA[

<div class="document">
<p>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.</p>
<p>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?</p>
<p>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.</p>
<p>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).</p>
<p>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.</p>
<p>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.</p>
<p>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.</p>
</div>

]]></description>
</item>

<item>
  <title>Does Amazon support Wikipedia?</title>
  <link>http://weblog.zamazal.org/amazon-wikipedia.html</link>
  <description><![CDATA[

<div class="document">
<p>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.</p>
<p>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?</p>
<p>BTW, one positive result of this issue is that it reminded me I should donate
to <a class="reference" href="http://wikimediafoundation.org">Wikimedia Foundation</a> during its current fundraising campaign.</p>
</div>

]]></description>
</item>

<item>
  <title>Scanning films with flatbed and film scanners</title>
  <link>http://weblog.zamazal.org/film-flatbed-scanner.html</link>
  <description><![CDATA[

<div class="document">
<p>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 <em>relevant</em> argument for film scanner superiority <a class="reference" href="http://ca.konicaminolta.com/products/consumer/digital_camera/dimage/dimagescan-dual3/pop.html">on their site</a>:
better optics.</p>
<p>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.</p>
<p>As for image quality I could observe the following:</p>
<ul class="simple">
<li>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&amp;w negatives.</li>
<li>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).</li>
<li>Nikon is much less prone to grain aliasing.</li>
<li>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).</li>
<li>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.</li>
<li>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.</li>
<li>Epson poor film holders make the scans prone to terrible reddish artifacts
near the both ends of film stripes.</li>
<li>There seems to be no relevant difference in the dynamic range capabilities of
the scanners when scanning negatives.</li>
</ul>
<p>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.</p>
<p>Besides the image quality convenience may also matter:</p>
<ul class="simple">
<li>Epson is much faster, I'd say I can scan a roll of film with it twice as
faster than with Nikon.</li>
<li>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.</li>
</ul>
<p>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.</p>
<p>HTH, although it's all mostly a personal opinion of course.</p>
</div>

]]></description>
</item>

<item>
  <title>Mike Oldfield -- Incantations</title>
  <link>http://weblog.zamazal.org/incantations.html</link>
  <description><![CDATA[

<div class="document">
<p>Mike Oldfield's <a class="reference" href="http://en.wikipedia.org/wiki/Incantations_%28album%29">Incantations</a> 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 (&quot;huh, who would like to listen to
all the long repetitions?&quot;) 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.</p>
</div>

]]></description>
</item>

<item>
  <title>Moving to git</title>
  <link>http://weblog.zamazal.org/git.html</link>
  <description><![CDATA[

<div class="document">
<p>Well, I switch the revision control system I use for the third time during last
years.</p>
<p>When I decided to try something else than CVS, I started with <a class="reference" href="http://www.gnuarch.org">GNU arch</a>.
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.</p>
<p>There were several reasonable choices among distributed revision control
systems: darcs, Mercurial and git.  I switched to <a class="reference" href="http://www.darcs.net">darcs</a> 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 <a class="reference" href="http://darcs.net/DarcsWiki/FrequentlyAskedQuestions#head-76fb029ff6e9c20468eacf3ff00d791e2cf03ecb">infamous darcs performance
problem</a>.  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.</p>
<p>The remaining choices were <a class="reference" href="http://www.selenic.com/mercurial/">Mercurial</a> and <a class="reference" href="http://git.or.cz">git</a>.  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 &quot;native&quot; tools for cooperation with CVS (this is important to
me as I usually work on projects with upstream CVS repositories).</p>
<p>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 <a class="reference" href="http://www.darcs.net/DarcsWiki/Tailor">tailor</a> 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 <em>the</em> future leading
free revision control system and I won't have to migrate again in the next
years.</p>
</div>

]]></description>
</item>

<item>
  <title>Installing pdaXrom</title>
  <link>http://weblog.zamazal.org/zaurus-pdaxrom.html</link>
  <description><![CDATA[

<div class="document">
<p>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.</p>
<p>So I decided to replace the Sharp operating system with <a class="reference" href="http://www.pdaxrom.org">pdaXrom</a>, 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.</p>
<p>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.</p>
<p>The second advice: If you end up with a &quot;dead&quot; C1000, you can recover it as
described on the <a class="reference" href="http://www.trisoft.de/c1000howto.htm">TRIsoft site</a>.  But there is an important missing detail
there: You need to press Fn+D+M to start the service menu, not only D+M.</p>
</div>

]]></description>
</item>

<item>
  <title>Damaged films</title>
  <link>http://weblog.zamazal.org/damaged-films.html</link>
  <description><![CDATA[

<div class="document">
<p>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.</p>
<p>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 <a class="reference" href="http://www.photorevue.cz/creativelab/">CREATIVE LAB</a> (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&nbsp;€
extra cost for postage, but it still looks like the cheapest way to get the
thing done right.</p>
<p>BTW the laboratories in Brno that show complete incompetence are Fosh foto and
Fotex (at Kobližná).</p>
</div>

]]></description>
</item>

<item>
  <title>Memory hogs on my computer</title>
  <link>http://weblog.zamazal.org/memory-hogs.html</link>
  <description><![CDATA[

<div class="document">
<p>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:</p>
<ul class="simple">
<li>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 .</li>
<li>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.</li>
<li>Some Xfce applets.  There are clearly memory leaks in them.  Well, unlike
GNOME panel and applets, Xfce applets work as expected otherwise.</li>
<li>Amarok audio player.  I really don't understand why an audio player needs
more than 100 MB of memory.</li>
</ul>
</div>

]]></description>
</item>

<item>
  <title>Sigur Rós -- ()</title>
  <link>http://weblog.zamazal.org/sigur-ros.html</link>
  <description><![CDATA[

<div class="document">
<p>I've recently listened to <a class="reference" href="http://www.sigur-ros.co.uk/band/disco/parenth.php">()</a>, the untitled album, by <a class="reference" href="http://www.sigur-ros.co.uk">Sigur Rós</a>.  It's an
interesting piece of music.  I can't say much about it, try listening to it
yourself.</p>
</div>

]]></description>
</item>

<item>
  <title>Civil engineering and free software</title>
  <link>http://weblog.zamazal.org/civil-engineering-software.html</link>
  <description><![CDATA[

<div class="document">
<p>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.</p>
<p>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.</p>
</div>

]]></description>
</item>

<item>
  <title>So they crippled another webshop</title>
  <link>http://weblog.zamazal.org/crippled-webshop.html</link>
  <description><![CDATA[

<div class="document">
<p>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.</p>
<p>I complained to the webmaster and he kindly explained me that using pixel based
sizes is necessary to get the look &quot;right&quot; 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.</p>
<p>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?</p>
</div>

]]></description>
</item>

<item>
  <title>Scanning software</title>
  <link>http://weblog.zamazal.org/scanning-software.html</link>
  <description><![CDATA[

<div class="document">
<p>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?</p>
<p>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.  &quot;Improvement&quot; 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 <em>individually</em>.  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.</p>
<p>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):</p>
<img alt="images/epson-sane-quality.png" src="images/epson-sane-quality.png" />
<p>Note two things:</p>
<ol class="arabic simple">
<li>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.</li>
<li>The regular pattern of vertical one pixel wide darker and brighter stripes
around edges of dark areas.</li>
</ol>
<p>As for the special ugly stripe, it helps turning quality settings <em>off</em>
(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:</p>
<img alt="images/epson-sane.png" src="images/epson-sane.png" />
<p>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:</p>
<img alt="images/epson-epson.png" src="images/epson-epson.png" />
<p>So I tried to get rid of the stripes by averaging each two neighboring stripes
into a new &quot;neutral&quot; 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:</p>
<blockquote>
<pre class="literal-block">
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
</pre>
</blockquote>
<img alt="images/epson-fixed.png" src="images/epson-fixed.png" />
<p>I think the result is pretty close (except for contrast adjustments) to what
Epson software produces, so it's probably the way to go.</p>
<p>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.</p>
</div>

]]></description>
</item>

<item>
  <title>Booting Debian from a USB drive</title>
  <link>http://weblog.zamazal.org/booting-from-usb-disk.html</link>
  <description><![CDATA[

<div class="document">
<p>I've recently installed Debian etch distribution on an external USB hard drive.
I was positively surprised how smooth the installation process was and how well
the resulting system worked.  Especially Czech environment was complete and
well set up for the Czech speaking user without any need of further
adjustments.  The release managers and the debian-installer team do clearly
good work and Debian 4.0 freeze may be short.</p>
<p>The only problem was how to boot from the USB drive.  Initially it appeared to
be easy as the computer offered USB booting in BIOS.  But that didn't work,
perhaps the BIOS was buggy.  So I decided to make a bootable CD for the system.</p>
<p>For the record, here is the process of making a bootable CD for an etch system
on an external USB drive.  Some steps may be redundant, I don't know, but the
final CD worked and this is what matters.</p>
<ul class="simple">
<li>Connect the USB drive to a similar computer, mount it and chroot into it.</li>
<li>Install the 'initramfs-tools' package.</li>
<li>Add the following module names to '/etc/initramfs-tools/modules':
'usb-ehci', 'usb-ohci', 'usb-uhci', 'scsi-mod', 'sd-mod', 'usb-storage'.</li>
<li>Run 'update-initramfs'.</li>
<li>You can leave the chrooted environment now.</li>
<li>Install 'syslinux' and read its documentation.</li>
<li>Create a syslinux working directory as described in the syslinux
documentation.  Name the kernel image file 'linux' unless you want to change
the defaults.  Don't forget to put the following option (the only one
required) into 'isolinux.cfg': 'APPEND initrd=initrd.img root=/dev/sda1'
(change the names of the initrd file and root partition accordingly).</li>
<li>Make the ISO image, burn it onto CD and boot it.</li>
</ul>
</div>

]]></description>
</item>

<item>
  <title>Scanning print films with Epson 2480</title>
  <link>http://weblog.zamazal.org/epson-2480-film.html</link>
  <description><![CDATA[

<div class="document">
<p>I've switched almost completely from using a compact digital camera to using a
film camera this year.  I scan my 35&nbsp;mm negatives with a low-end flatbed
scanner, namely Epson Perfection 2480 Photo.  It is possible to obtain
reasonable results using that cheap device, but it's not easy.  I've been
learning a lot during the process and I'd like to share my experience in the
posts here, perhaps it helps someone.</p>
<p>First, what can one expect?</p>
<p>As for the scanner dynamic range, I think it's sufficient for scanning amateur
print films, I haven't observed any problems in this area.</p>
<p>As for the scanner resolution, Epson claims something about 2400&nbsp;dpi regarding
that scanner.  I'd say such numbers are pure marketing crap nowadays for two
reasons: 1. it's not defined what the number means; 2. whatever it's supposed
to mean it has probably little to do with reality, i.e. the real scanner
resolution.  According to internet rumours and my own observations, such as
down and upsampling scanned pictures and comparing scans with prints, I
estimate the actual scanner resolution performance is very roughly around
1000&nbsp;ppi.  That means the spatial information the scanner is able to capture
from a standard 35&nbsp;mm film field is present in a picture of a minimum size of
about 1500x1000 pixels.</p>
<p>So in theory the scanner should be sufficient for both my primary target
medium, a 1280x1024 computer screen, and my secondary media, occasional prints
not larger than A4.  In practice it's not that easy but more on this next time.</p>
<p>Wouldn't it be worth to buy a better scanner?  I don't have any experience with
current more expensive scanners, but from what I've read and seen on the net, I
think they provide somewhat better results with significantly higher comfort
for much more money.  Higher Epson flatbed scanners such as 4x90 or V7x0
produce better results and offer hardware features for dust removal, but
increase in the device cost is significantly higher than increase in the
resulting scan quality.  Low-end &quot;4000&nbsp;dpi&quot; dedicated film scanners give even
better results for even more money.  Drum scanners produce much better scans
than Epson 2480 for 100&nbsp;times more money.  Basically it's your choice whether
you invest much more money into better scanning hardware producing good results
or much more time into scanning process using a cheap scanner producing
acceptable results.  Or whether you buy a good digital camera equipment and get
rid of scanning entirely.</p>
</div>

]]></description>
</item>

<item>
  <title>CUPS 1.2 finally working</title>
  <link>http://weblog.zamazal.org/cups-1.2.html</link>
  <description><![CDATA[

<div class="document">
<p>About a week ago, I've upgraded CUPS from 1.1 to 1.2 on my print server.  I
know one should never touch a working CUPS installation, but as Debian 4.0 is
based on CUPS 1.2 I'd have to make the upgrade sooner or later anyway.</p>
<p>Of course, after the upgrade my printing stopped working as usually.  As this
was my second CUPS 1.1 to 1.2 upgrade attempt I already knew about some
problems of the upgrade process and could get run at least the CUPS HTTP and
IPP interfaces.  But the printers worked in weird ways such as printing a
single page in several pieces put on separate sheets or stopping to work after
finishing a printing job.</p>
<p>To keep the story short, after a week of various efforts I ended up with
complete removal of printing software on the server and its reinstallation.
Then the CUPS HTTP configuration interfaces started to offer right
configuration items and after a few attempts I could get my printing run
properly.</p>
<p>I can only hope that after the upcoming Debian 4.0 release Debian slows down
its release cycle again, so that I won't have to suffer all the software
upgrade headaches each one or two years...  In the meantime, let we software
developers think more about impact of the changes we make to our great
software.</p>
</div>

]]></description>
</item>

<item>
  <title>Fighting Czech Spammers</title>
  <link>http://weblog.zamazal.org/czech-spammers.html</link>
  <description><![CDATA[

<div class="document">
<p>Some Czech spammers are completely impudent and ignoring Czech law forbidding
spamming activities.  Europe should be civilized enough to be able to prevent
such behavior here.</p>
<p>I've received another piece of spam from Hotel u Lípy today.  Enough is enough,
so I started looking for possibilities to retaliate, resulting in posting a
grievance against them to <a class="reference" href="http://www.uoou.cz">Úřad pro ochranu osobních údajů</a> (The Office for
Personal Data Protection) that is responsible for dealing with such cases.
They have <a class="reference" href="http://www.uoou.cz/index.php?l=cz&amp;m=left&amp;mid=11:03&amp;u1=&amp;u2=&amp;t=">an electronic form</a> allowing Czech citizens to report abuse of the
anti-spam law.  Similar means should be available in other civilized countries
as well.</p>
<p>I don't think it's much useful to report random spammers who may not be well
aware about what they are doing.  Just complaining to them and their ISPs may
be a better way to deal with it.  But we shouldn't hesitate to officially fight
regular spammers ignoring private complaints.  Although the office apparently
lacks man power to deal with the reports quickly, they should be able to
intervene some way against the spammers in the final result.</p>
</div>

]]></description>
</item>

<item>
  <title>Ratpoison, Conkeror</title>
  <link>http://weblog.zamazal.org/ratpoison-conkeror.html</link>
  <description><![CDATA[

<div class="document">
<p>With the increasing complexity of modern user interfaces the number of annoying
bugs grows.  What is worse, number of long standing unfixed annoying bugs
grows.  The overall number of bugs grows and I'm able to do something only with
a small part of them.  Complex user interfaces have been being released without
coming through a serious testing process (a typical example is GNOME).</p>
<p>One way how to handle this situation is to move from the complex user
interfaces that don't work to simpler ones that do.  I've recently switched
from Sawfish and GNOME panel to Ratpoison and XFCE panel and I've been happy
with the change so far.  <a class="reference" href="http://www.nongnu.org/ratpoison/">Ratpoison</a> is, together with <a class="reference" href="http://www.nongnu.org/stumpwm/">Stumpwm</a> and <a class="reference" href="http://modeemi.fi/~tuomov/ion/">Ion</a>,
a very simple window manager -- no window buttons, no borders, no workspaces,
no systray, no customization dialogs, no mouse support.  Instead you receive a
window manager that works, can be easily and completely operated from a
keyboard, utilizes maximum of your screen space and is well customizable.  I
was surprised how little of the complex functionality of other window managers
I actually need.  Ratpoison seems to offer all I need and to be more
comfortable for me than classic window managers.</p>
<p>At the same time I switched from Firefox to <a class="reference" href="http://conkeror.mozdev.org/">Conkeror</a>.  The primary reason
was that I got annoyed by being unable to reasonably operate Firefox from
keyboard.  Conkeror is similar to the window managers mentioned above (no
wonder -- Ratpoison, Stumpwm and Conkeror were written by the same author).
There are no toolbars, menus and other decorations, it can be operated from
keyboard and it uses Emacs concepts (interactive commands invoked by M-x,
buffers, mode line, minibuffer, echo area).  Unlike Ratpoison, Conkeror has not
been feature complete yet but it's possible to invoke the standard Firefox
interface from it in case you need it.  Additionally Conkeror is just another
user interface to the web browser and as such it can't fix Firefox fatal bugs
(such as crashes or freezes on certain pages).  Anyway, I like it and I don't
miss the standard Firefox interface often.</p>
<p>Well, here is a screenshot of my current desktop, do you like it? :-)</p>
<img alt="images/ratpoison-conkeror.jpg" src="images/ratpoison-conkeror.jpg" />
</div>

]]></description>
</item>

<item>
  <title>First year over</title>
  <link>http://weblog.zamazal.org/first-year-over.html</link>
  <description><![CDATA[

<div class="document">
<p>I've successfully finished my first year of distant study of civil engineering.
Some fun, some hard work, as the distant study is mostly based on working out a
lot of exercises.  You can either actually make the exercises or you can copy
them (which is formally disallowed of course).  IMO the first way, although
sometimes very time consuming, is better than learning the subjects by
repeating exams and it is definitely much more effective measured by the
actually gathered knowledge.</p>
<p>It proved to be manageable, but I can't recommend combining a regular job,
building your new house by your own hands, extending your family, studying a
school, etc.  It's somewhat demanding :-).  I hope I'll be able to manage
things better in the next years.</p>
</div>

]]></description>
</item>

<item>
  <title>Film sensitivity</title>
  <link>http://weblog.zamazal.org/film-sensitivity.html</link>
  <description><![CDATA[

<div class="document">
<p>When I scanned photos from the Fuji Superia 400 film I was very unhappy with
grainy shadows.  The grain seems to be really worse there than in brighter
areas even when considering the effect of higher noise visibility in dark
areas.  I couldn't get rid of it even when I tried to significantly overexpose.
By chance I found explanation of the problem in an old issue of the Czech PHOTO
life magazine.</p>
<p>Actual sensitivity of negative <em>amateur</em> Fuji films (and this is likely to
apply to other vendors' films as well) is very different from what one could
assume looking at the declared ISO number.  First, it is actually significantly
higher than declared, protecting you from underexposition.  Second, maximum
sensitivity (i.e. the ability to capture minimum light without underexposition)
is about the same regardless of the declared sensitivity, the difference
between Fuji Superia 100 and 400 is reported to be only about 0,5 EV.  When you
expose Fuji Superia&nbsp;100 at ISO 50, you can go up to 4&nbsp;EV from the middle
towards darkness before the material gets underexposed, while when you expose
Fuji Superia&nbsp;400 as ISO 200, you've got only about 2,5&nbsp;EV.</p>
<p>This explains what I observe -- even when overexposing the ISO 400 film twice,
there is a big risk of underexposed shadows, resulting in overgrown grain (note
that according to Fujifilm specifications standard grain size should be about
the same in properly exposed Superia 100 and 400).  Indeed, scanning my latest
Fuji Superia 100 film seems to confirm the facts.  When I compare results from
an ISO 400 film exposed as ISO 200 and from an ISO 100 film exposed as ISO 70,
there is not much difference in the look of the grain in the highlights.  But
the grain is much worse in shadows of the ISO 400 film, while in the ISO 100
film the grain is about the same as in highlights there.  So there is no point
for me to use an ISO 400 film which is more expensive and provides lower
dynamic range, while it offers only slight advantage in maximum sensitivity.</p>
<p>Sensitivity is one of the areas where digital easily beats film.  Where I'm
limited to ISO 50-100 with film, good digital cameras can go safely up to ISO
400-800.  Additionally, the higher depth of field allows to use one step wider
aperture.  And finally, image stabilizers become common, which adds further 2-3
steps.  Summed up, DSLRs can provide at least 6 EV advantage over film in
nature photography.</p>
</div>

]]></description>
</item>

<item>
  <title>Moonlight photography</title>
  <link>http://weblog.zamazal.org/moonlight-photography.html</link>
  <description><![CDATA[

<div class="document">
<p>I've finally managed to process my photos from the last winter.  You can look
at samples of <a class="reference" href="http://www.photo.net/photodb/folder?folder_id=634209">my photos taken under moon light</a>.  They are not good photos
but they show how moonlight photography can look like.  Note the photos are
somewhat shaky because I forgot the remote control at home and had to hold the
shutter button by hand for the whole time of exposure.</p>
</div>

]]></description>
</item>

<item>
  <title>Back to film</title>
  <link>http://weblog.zamazal.org/back-to-film.html</link>
  <description><![CDATA[

<div class="document">
<p>After using my Olympus C-2100 UZ digital camera for several years exclusively I
slowly revive my old film equipment.  Despite the great practical advantages of
digital cameras such as immediate feedback, in-camera processing, no dust (with
a proper camera), no scratches, data safety, low snapshot costs, low weight,
etc., there are still some problems.  I was very happy with the Olympus camera
initially and I learned a lot using it.  But with the learning process the
camera's drawbacks became apparent: grain replaced by noise and aggressive
image processing, too low depth of field replaced by too high depth of field,
too low contrast replaced by too high contrast, high sensitivity replaced by
inability to take long exposures.  I consider the 10x zoom C-2100 lens being
quite good, but it has its limits too: it doesn't provide wide angle focal
range and it suffers from occasional chromatic aberration.</p>
<p>Ironically, the camera buries itself by teaching me.  The clever guys at
Olympus have probably even implemented it as a feature -- while the camera
costed more than all my previous photographic equipment together, it lasted
less than any of the other components.  It took only a bit more than 3 years
before it started to suffer from serious mechanical problems.  So I started to
look for a replacement not only because of my new requirements, but also
because of possible future complete failure of the made-in-Japan camera.</p>
<p>Compact digital cameras haven't made much progress since Olympus C-2100.  The
number of pixels increased significantly, but without big impact on the
resulting picture quality.  The processing algorithms were improved, but that's
basically all.  It makes no point for me to buy another camera with a small
sensor.  And good digital cameras are still too expensive (Sony DSC R1 being
the cheapest one, but still exceeding what I could reasonably pay).</p>
<p>In this situation I've started to make experiments with my old Praktica-based
equipment about a year ago.  I hope it can complement the Olympus camera or
even to replace it completely for some time in case of its complete failure.
One can't resist nostalgia when holding the old equipment in his hands: Solid
construction, no batteries needed, the feel of complete control over the
camera, listening to the shutter and mirror noise again after the years of
silence...  But the primary result of this change (not counting changes to
one's physical condition caused by carrying the heavy equipment) is that I have
to be very careful with taking pictures again.  It starts by changing lenses,
mounting the camera to a tripod, manual focusing, guessing proper depth of
field, considering metering corrections, etc.  It takes a lot of time to take a
picture, but it's the more amusing part.  The tedious part is processing the
developed film.  I'm not going to make prints at minilab, I want to process the
images myself electronically and store them in my computer.  And this is no
easy thing with film.  I'll write more about my experience with this later.</p>
</div>

]]></description>
</item>

<item>
  <title>Multiseat finally working</title>
  <link>http://weblog.zamazal.org/multiseat.html</link>
  <description><![CDATA[

<div class="document">
<p>When I upgraded my computer, I wanted to make it available to my family even
when I'm sitting in front of it (this happens most of the time).  Natural way
to allow this is to connect additional terminals to the computer.  The
simplest, cheapest and power saving kind of terminal consists just of a set of
I/O devices, such as a monitor, a keyboard and a mouse or a TV with a remote
control.</p>
<p>So I equipped the new computer with two graphics cards, assuming that
connecting multiple input and output devices to the computer should be just a
matter of having corresponding number of graphics cards and free USB ports
available.  Big mistake!  Never, never underestimate software problems.  It
took me several months to make the multiseat setup actually working and still
not without problems.</p>
<p>The very first problem was that X.Org 7.0 refused to run on the second graphics
card at all.  This is some mismatch between X.Org 7.0/6.9 and recent Linux
kernels.  After a lot of experiments and googling I finally found <a class="reference" href="https://bugzilla.novell.com/attachment.cgi?id=86821">a patch that
works for me</a>.</p>
<p>Now I was able to run two different X servers, but only on different Linux
consoles, i.e. not accessible in parallel.  I followed the very nice <a class="reference" href="http://blog.chris.tylers.info/index.php?/archives/14-Multiseat-X-Under-X11R6.97.0.html">Multiseat
HOWTO</a>, but it still didn't work -- my X session has always frozen when I
started the second instance of the X server sharing the console.  After
additional experiments and googling I've found it might be worth to try running
different video drivers on each of the graphics cards.  The two graphics cards
I've got in my computer are the same, so I tried to run one of them with the
X.Org ATI driver and the other with the ATI proprietary driver.  Indeed, I can
run two X servers in parallel now.  Not without limitiatons: While the free
X.Org driver runs fine, the ATI proprietary driver runs only on the first
graphics card (it refuses to start on the second card), without 3D acceleration
(compilation of the fglrx kernel module failed) and it freezes the computer
when one logs out (this is a real problem that I don't understand since the X
server is not restarted on logout).  Another problem is that X.Org doesn't
allow switching to a Linux text console when running multiseat.</p>
<p>An additional interesting observation is that one can't rely even on such basic
things like that a keyboard works.  My USB keyboard stops working very soon
after boot and needs to be unplugged and plugged in again.  Then it works fine,
but if I do it when X has already been started, the mouse connected to the USB
hub built in the keyboard stops working completely.  AFAIK there is a lot of
problems with USB keyboards on Linux, often without solution.  Well, this is so
called computer age...</p>
</div>

]]></description>
</item>

<item>
  <title>CUPS problems again</title>
  <link>http://weblog.zamazal.org/cups-sucks.html</link>
  <description><![CDATA[

<div class="document">
<p>Well, not only proprietary drivers are crappy, they are just more crappy than
anything else.  Free software sometimes suffers from serious problems too.</p>
<p>I use a dedicated virtual machine to manage my printing services.  One of the
reasons I've put it on a separate machine is stability: While software on my
other machines is updated, the printing server can remain untouched.</p>
<p>Now I know I can't expect that kind of stability from CUPS.  I often upgrade my
workstation.  Suddenly printing from GIMP and PhotoPrint stopped working with
the error message saying something like &quot;Bad IPP request&quot;.  After some attempts
to find out what's wrong I've found that my CUPS client is of newer version
than the CUPS server.  Great -- unless you use the same client and server
software version on your network, CUPS may not work.  So I had to upgrade the
CUPS server, just because a workstation happened to use newer client version.</p>
<p>The CUPS server upgrade wasn't without trouble.  Together with the 1.1 -&gt; 1.2
transition the main configuration file was changed.  Well, that's OK (only if I
wasn't forced to fiddle with new configuration <em>right now</em> because of the
client software update!).  But I couldn't access the printing server because of
some permission problem.  After significant amount of time spent on discovering
what's wrong I've finally got it: The 'Allow' directive doesn't work with
host name, it requires an IP address.  Sigh.</p>
<p>So CUPS started to work with my parallel port printer.  Not so with the printer
connected through USB.  It reported to be unable to open the corresponding USB
device.  Even setting the device permissions to 666 didn't help.  I ended up
with downgrading CUPS to 1.1 on both the server and client machines.</p>
<p>I've never liked CUPS.  CUPS is not a bad idea and it's fine when it happens to
work well, but it has been making troubles all the time I use it.  From what
I've seen for several years of CUPS usage I have to say that Linux printer
management is apparently in incompetent hands (not sure whether upstream or in
Debian).</p>
</div>

]]></description>
</item>

<item>
  <title>digiKam</title>
  <link>http://weblog.zamazal.org/digikam.html</link>
  <description><![CDATA[

<div class="document">
<p>My long term observation about GNOME and KDE is that GNOME is stronger in
desktop, while KDE is stronger in applications.  One of the excellent KDE
applications is <a class="reference" href="http://www.digikam.org">digiKam</a>.</p>
<p>The most popular free image processing tool, <a class="reference" href="http://www.gimp.org">GIMP</a>, hasn't succeeded to
become a tool for serious work.  Its lack of important features (such as 16-bit
color support) and poor user interface make it suitable just for occasional
use and perhaps for web designers.  Lack of free usable photo processing and
management tools has motivated me to develop my own photo processing program as
a part of my <a class="reference" href="http://www.zamazal.org/software/springtail/index.html">Springtail</a> Lisp tools.  But due to lack of time and zero
support from McCLIM developers Springtail didn't provide completely satisfying
results.</p>
<p>About a year ago I discovered digiKam.  After trying it I've abandoned the
Springtail photo application development immediately.  Not that digiKam offered
all the features present in Springtail and everything I needed, but it provided
interesting features, good user interface and was well maintained.  It was
clear to me that this may be the right tool and it made no sense to invest my
effort into development of my own tool instead of helping a promising project.</p>
<p>I can say that digiKam fulfills my expectations and I recommend it to photo
enthusiasts who look for a good photo editing and management tool.  It can't do
everything and there are many features that could be improved, but this is up
to us -- we can file bug reports, vote for bugs and make patches.  I believe
this project is well maintained and it's worth to help it.</p>
</div>

]]></description>
</item>

<item>
  <title>Proprietary drivers and Linux</title>
  <link>http://weblog.zamazal.org/ati-sucks.html</link>
  <description><![CDATA[

<div class="document">
<p>ATI graphics cards suck and I can't recommend buying them.  I've spent
significant amount of time trying to get run their proprietary drivers on Linux
and the conclusion is that the X.Org free drivers are dozen times better than
those from ATI, despite 3D acceleration and TV-out don't work with <a class="reference" href="http://www.zamazal.org/linux/radeon-x300se.html">my ATI
card</a>.  Effectively, my new ATI card is a 3D incapable device without TV
output.</p>
<p>I don't believe NVidia is much better -- I've once had particularly bad
experience with an NVidia graphics card.  Intel cards are well supported, but
does Intel make anything else than onboard cards?  We clearly miss real
competition on the hardware market.</p>
<p>I really can't understand the ignorance of hardware vendors.  They are
incapable to produce stable and well working drivers for Linux.  Well, why
don't they provide specifications to their devices then and let people make
good drivers <em>for free</em>?  What's so secret on accessing 3D graphics
acceleration or making a printer to print a borderless photo?!</p>
<p>Will Linux and other non-proprietary operating systems still be usable without
essential modern hardware features?  I doubt.  But what's the solution?
Current market turns into unbreakable oligopoly in many areas, so the natural
market mechanism doesn't work.  Open hardware would be the best solution, but
it seems this is not something that could become widely accessible in the
foreseeable future.  Apparently there is not much else to do now than
continuing the reverse engineering battle. :-(</p>
</div>

]]></description>
</item>

<item>
  <title>DVDs for reasonable price</title>
  <link>http://weblog.zamazal.org/levne-knihy.html</link>
  <description><![CDATA[

<div class="document">
<p><a class="reference" href="http://www.levneknihy.cz">KMa s.r.o. -- Levné knihy</a> is a Czech publishing company specialized on
publishing and selling cheap books, especially classic literature with expired
copyrights.  Now they publish cheap movies on DVDs as well, for a price of
3-4&nbsp;€, that is about 1% of common salary here and easily affordable.</p>
<p>They publish various kinds of movies, including large selection of excellent
movies by Ingmar Bergman and Akira Kurosawa.  Thanks to them I can watch movies
on DVDs for the first time now.</p>
</div>

]]></description>
</item>

<item>
  <title>OSA can celebrate another victory</title>
  <link>http://weblog.zamazal.org/osa-thiefs.html</link>
  <description><![CDATA[

<div class="document">
<p>OSA (The Performing and Mechanical Rights Society of Composers, Authors and
Publishers) was successful again with their lobbying.  The upgrade of Czech
copyright law brings great news for them: While it's now illegal to make any
copies of a protected work (so you can't make backup copies of your CDs
anymore!), we not only still pay fees for <em>each</em> <em>empty</em> CD or DVD but the
range of the taxed devices and media was extended.  So the law either
introduces pure taxes paid to an organization you have nothing to do with or it
defines a priori compensation for criminal activities, paid by all the
citizens.  Both looks pretty absurd to me.</p>
<p>The problem is how to boycott this.  Even if you ignore the bastards
completely, i.e. don't listen to their music, don't watch their movies, etc.,
you still have to pay them in case you use photocopy services, buy DVD media,
memory cards, music players, printers, recorders and other devices, regardless
of the purpose you use them for (such as storing your own data or works).</p>
</div>

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