Archive for the ‘Hardware’ Category

MeeGo? Where are you?

Monday, July 9th, 2012

There is a rumour that a small Finish company called Jolla lead by ex-Nokia-employees is trying to revive MeeGo. (here, here and hier) Is there a new chance for a real GNU/Linux mobile operating system with great hardware support being free like in freedom, not free like in Android? And they want to use Qt instead of this hip, kinky HTML5+JavaScript (cf. Tizen). Sounds like really good news, but unfortunately I am not that confident. There have been so many setbacks. Maybe it will stay a dream in the near future. :( What are your opinions about it?

PS:
Yes, I know about Mer. However, I cannot judge its current state, of course I hope there will not be too much fragmentation of Mer/MeeGo/Jolla/Tizen.

Old Regression by Leonardo da Pisa

Saturday, June 11th, 2011

After reading this blog post I thought a bit about endianness (big-endian is just bad), and while having a shower a theory came into my mind: Maybe Arabs had little-endian integers (meaning least-significant bit first) but wrote (and still do) from right to left (meaning least-significant bit/digit at the right). And when Leonardo da Pisa (Fibonacci) brought Arabic numerals to Europe, he wrote in the same style, not flipping the digits, hence establishing big-endian. In fact I could verify that with Wikipedia. But I also noticed that this “bug” has been there before, Indians write from left to right (Wikipedia told me about a coin in Brahmi written from right to left, but that was before there were any numerals), and they have always used big-endian. Thus Arabs fixed that issue (maybe not knowingly), but stupid Europeans did not get why big-endian is stupid. Furthermore, big-endian numerals look more like those stupid Roman numerals, and our usual way of vocalising them is like in Roman times. And because of Leonardo da Pisa there are those stupid architectures using big-endian representation (fortunately not x86, amd64), causing non-portability, byte-order-marks and all that stupid stuff. And left-shifts could actually be left-shifts and right-shifts could be right-shifts.

Short list of arguments for little-endian:

  • Value of a digit d at position i is simply d·b**i (b is the base). That would obviously be the most natural representation if you would implement integers by using bit-arrays. It does not depend on the length, no look-ahead required.
  • You can simply add numbers from left to right (no right-alignment for summation).
  • For radix sort you can begin from left.
  • Simple cast between longer and shorte integers without moving any bits.
  • You do not need words like “hundred”, “ten-million”, “billiard” etc., because you can interprete a sequence online without look-ahead.
  • Repeating modulo and integer division by the base gives little-endian-representation.
  • The least-significant bits carry more interesting number theoretical information.

Well, big-endian is more like lexicographic order, although I am not sure if it is clearly better for natural languages. For division you have to start with the most-significant bit, but—hey—division is obviously not as important as all the other operations where you start with the least-significant bit. Of course sometimes little-endian is not a good notation, for measurements one should use floating point numbers (in a decimal world called “scientific notation”) and the mantissa should start with the most-significant bit/digit, after the exponent to avoid look-ahead (unlike the scientific notation).

If Leonardo da Pisa would have thought a bit about what he is doing, there would not be all those drawbacks! Just my thoughts about that regression. ;)

Fun with a Wacom-Tablet and openSuSE

Sunday, February 20th, 2011

Fun! Graphics tablets! Oh, wait, why did I mention the distribution? And The User is not one of those great artists using Krita, he is a clumsy nerd. May it be irony? Maybe, but there has actually been some fun.

Okay, I started at 1:00 last night, I wanted to try a “Wacom Intuos2 9×12” (`xsetwacom list`, I guess it refers to the size) with openSuSE (of course, I do not use any non-GNU/Linux-system). Well, I had some weird problems: First I could just move the cursor, no clicks, then I installed some stuff, and I could use the pen as a mouse, but without pressure detection or anything like that and with an awkward behaviour: After having drawn a line (i.e. after releasing) the cursor did no longer move, until pressing it again or lifting it a few centimetres, drawing lines, hatching etc. are of course not possible that way. So I continued playing around, xsetwacom could not recognize the tablet, openSuSE’s xinput version has this bug, so I was very confused, although it is only a bug in the output and does not affect xsetwacom. I have upgraded X to version 7.6 using this repository, but now fglrx failed, ugly backtraces at startup. I started in failsafe-mode without fglrx and after short time the tablet worked with Krita and different pressures etc. It was 4:30, I was quite tired, and I went to sleep. But of course I wanted to get fglrx back, I know, it is a proprietary driver, but without it 3D is terrible and with fglrx my battery life is one hour longer (without fglrx only 90 minutes or something like that). I downgraded the X back to version 7.5, but after some time (maybe two hours of useless recompiling, reinstalling of drivers, rebooting) I noticed that ATI provides drivers for X.org 7.6 at their website, unfortunately they do not provide official openSuSE-repositories any longer, so I had inofficial, outdated fglrx installed. Now I was confident, it had already worked with 7.6, upgrading, running the official ATI-driver-installation-script (it even generates a rpm, nice)… It did not work, I tried some source-version for the wacom-kernel-module and the xf86-input-driver, but it did not work. But finally I noticed that xorg-x11-driver-input had not been updated, probably because of the dependencies of the inofficial wacom-driver-rpm. And finally everything worked some minutes after 17:00 (I had been afk for few hours, and do not forget sleeping, so it took less than 16 hours ;)). It is awesome! The tablet is awesome! Krita is awesome! My drawing-skills are awesome, ehh, not awesome!

Long story short for those of you wanting to use a wacom-tablet with openSuSE 11.3:

  • `zypper ar “http://download.opensuse.org/repositories/X11:/XOrg/openSUSE_11.3/X11:XOrg.repo”`
  • `zypper dup`
  • Make sure, all xorg-x11-packages are now up-to-date
  • Install wacom-kmp-desktop (for desktop kernel) and xorg-x11-driver-input-wacom from some repositories, have a look at http://software.opensuse.org
  • Alternatively visit http://linuxwacom.com and install the drivers from source(git://linuxwacom.git.sourceforge.net/gitroot/linuxwacom/xf86-input-wacom, git://linuxwacom.git.sourceforge.net/gitroot/linuxwacom/linuxwacom)
  • Reboot, everything should works now

kcm_tablet does not work for me, maybe it will magically work after some rebooting, but for now it does not detect the tablet. However, the standard-configuration is okay and I can still use xsetwacom for configuring the device. I do not want to tell you about my attempts with UDBA-graphics-driver-installation and the long startup-times of fglrx.

My first work I have stored (the bamboo is a Krita-default-brush :D): show image in full size.