you may experience some problems with arrow keys, pg up/pg down and home/end keys with vmware 6.5 and Ubuntu Linux Intrepid 8.10.

a workaround for those problems is to create a file named config under .vmware folder in your home directory and fill it with the following text:

xkeymap.keycode.108 = 0×138 # Alt_R
xkeymap.keycode.106 = 0×135 # KP_Divide
xkeymap.keycode.104 = 0×11c # KP_Enter
xkeymap.keycode.111 = 0×148 # Up
xkeymap.keycode.116 = 0×150 # Down
xkeymap.keycode.113 = 0×14b # Left
xkeymap.keycode.114 = 0×14d # Right
xkeymap.keycode.105 = 0×11d # Control_R
xkeymap.keycode.118 = 0×152 # Insert
xkeymap.keycode.119 = 0×153 # Delete
xkeymap.keycode.110 = 0×147 # Home
xkeymap.keycode.115 = 0×14f # End
xkeymap.keycode.112 = 0×149 # Prior
xkeymap.keycode.117 = 0×151 # Next
xkeymap.keycode.78 = 0×46 # Scroll_Lock
xkeymap.keycode.127 = 0×100 # Pause
xkeymap.keycode.133 = 0×15b # Meta_L
xkeymap.keycode.134 = 0×15c # Meta_R
xkeymap.keycode.135 = 0×15d # Menu

Upgrade to Ubuntu Linux Intrepid 8.10 has been fairly flawless.

Click here for the full tutorial on Ubuntu Linux Intrepid 8.10 compatibility with HP Pavilion DV laptops.

The only notable caveats are:

1. Bug #279187 makes the computer speakers beep loudly in a random way while booting, shutting down, suspending, resuming, logging off. This appears to be related to the use of restricted nvidia drivers (with today update of nvidia-glx-173 (173.14.12-1-0ubuntu4) to 173.14.12-1-0ubuntu5 this issue is always affecting also version 173 of the drivers.

   A valid workaround seems to be removing the ’splash’ argument from the kernel boot line in /boot/grub/menu.lst With this workaround also version 177 of the nvidia restricted drivers work as expected.

2. It seems not possible to enable the nvidia restricted drivers through jockey. If jockey (Hardware Drivers under System -> Administration menu) hangs simply install the package nvidia-glx-177 or nvidia-glx-173 via Synaptic Package Manager, then try again to enable the driver through Hardware Drivers.

   If you get error: glx-173_173.14.12-1-0ubuntu4_i386.deb: trying to overwrite `/usr/lib/libGL.so.1′, which is also in package libgl1-mesa-glx just reinstall packages libgl1-mesa-glx and xserver-xorg-core before installing the drivers.

3. The CUPS PDF printer gets removed. To have it again available you have to re install package cups-pdf
   
4. If you had a previously configured printer and it does not work any more check the ‘Printer Properties’ in System -> Administration -> Printing. If in field Printer Status you get the following error:

   unable to start filter ‘rastertospl2′

   this means the drivers have been updated and you need to re-configure them.
   Click on the Change button on the right of Make and Model field and follow the wizard with confidence.
   When you have finished you may print again.

taken from http://www.linux.com/feature/138511

How to scan and OCR like a pro with open source tools

for i in $(seq --format=%003.f 1 150); do
  echo Prepare page $i and press Enter
  read
  scanimage --device 'brother2:bus1;dev1' --format=pnm --mode 'True Gray' --resolution 300 -l 90 -t 0 -x 210 -y 200 --brightness -20 --contrast 15 >scan-$i.pnm
done

for i in $(seq --format=%003.f 1 150); do
  echo preparing page $i
  unpaper scan-$i.pnm unpapered-$i
  convert unpapered-$i.pnm prepared-$i.tif && rm unpapered-$i.pnm
done

for i in $(seq --format=%003.f 1 150); do
  echo doing OCR on page $i
  tesseract prepared-$i.tif tesseract-$i -l eng
done

for i in $(seq --format=%003.f 1 150); do
  tail -n +2 tesseract-$i.txt >text-$i.txt
done

#!/bin/sh
# newlines to spaces
tr '\n' ' '
# only one space character at a time
sed 's/[[:blank:]]{2,}/ /'
</dev>

With Firefox 3.0 some autocompletion features have been introduced, specifically the ones concerning the location bar can be somehow annoying. Here’s how to disable them.

To prevent entries from History or bookmarked items from appearing but show those that you have specifically typed into the Location Bar (url bar), use about:config to toggle browser.urlbar.matchonlytyped to true. To completely disable the Location Bar autocomplete function in Firefox 3, modify the preference browser.urlbar.maxRichResults to 0 (zero). [1]

For additional information about modifying the “Smart Location Bar” behavior in Firefox 3, see the MozillaZine forum topic, Customising the Firefox 3 Location Bar and this forum post.

——————————————————————————————

Con Firefox 3.0 sono state introdotte alcune funzionalità di autocompletamento automatico, in particolare quella riguardante la barra degli indirizzi. Ecco come disabilitarle:

- nella barra degli indirizzi di Firefox digita about:config
- rassicuralo che sarai molto prudente
Se vuoi
a) evitare che ti appaiano i link che hai inserito nei bookmark:
- cerca la stringa browser.urlbar.matchonlytyped (usando la barra di ricerca in alto)
- cliccaci sopra due volte e scrivi true

b) evitare che ti compaia qualsiasi link che hai recentemente digitato nella barra dei link:
- cerca la stringa browser.urlbar.maxRichResults
- cliccaci sopra due volte e scrivi 0 (zero).

nota: in questo secondo caso puoi sostituire 0 con un numero qualunque che indica quanti link mostrare nel menu a tendina che compare quando state scrivendo un indirizzo.

here is an interesting thread about batch resizing images.

http://ubuntuforums.org/showthread.php?t=170862

Basically you can use gThumb (opening multiple files at once with this app) or digikam. GIMP currently has support for batch operations only in its development branch.

After facing for a while the extremely annoying bug that shows itself as

- losing the touchpad vertical scroll functionality after a while

- losing the touchpad sensitivity after some more time, this occurs more and more often during the same session

- ending with both stuck touchpad and keyboard

I managed to figure out a workaround.

I have noticed that there was a line in /etc/X11/xorg.conf under

Section “InputDevice”
Identifier “Synaptics Touchpad”
Driver “synaptics”

that stated an auto-dev protocol
Option “Protocol” “auto-dev”

Since I knew that xserver-xorg-input-synaptics is almost unmaintained (the latest available version dates July 2007 and is simply a git version, not a stable release), I thought the former maintainer had left some unstable and untested code into the driver.

Thus I simply changed that line leaving ou the -dev

Option “Protocol” “auto”

Now it’s been more than a week I’m not experiencing that issue any more and apart from that nothing has changed as of touchpad functionality. I just wonder what the development code has that the stable one does not in order to make Ubuntu devs choose it for default settings.

The related launchpad bug is https://bugs.launchpad.net/bugs/34501

Despite the slightly higher resolution (800 vs 768) vertical space is always a bit constrained on widescreens. This is even more noticeable with Gnome which has two panels, at the top and at the bottom, that use at minimum size 50 pixels both. Some other 20 px get wasted in the application titlebar, around 15 px in its statusbar, countless in horizonal scrollbars, menu bars, toolbars and whatsoever.

A clever way to decrease the waste in space due to Gnome is to enable the autohide feature in panel preferences (simply rightclick on an empty area of the bottom panel and choose preferences).

However, after you use this feature a few days you may get annoyed by the excessive delay in showing it up again. As everything on Linux, this can be hacked in Gnome registry! Here is how:

press ALT+F2

type in gconf-editor

navigate to string /apps/panel

right here you find some deprecated keys that change the behavior globally, do not change them.

go to a lower level e.g. /apps/panel/toplevels/bottom_panlel_screen0

here you may

untick enable_animations otherwise you’ll get a dirty animation after you shorten the reacting time

change unhide_delay for example to 200 ms.

That’s it!

Undervolt your notebook CPU for longer battery life

“Undervolting is the practice of reducing the supply voltage of a computer’s CPU. There are mainly three reasons to do so:

1. Reduce power consumption
2. Reduce heat generation
3. Reduce fan noise

1. This howto depends on the kernel module acpi-cpufreq to control your cpu. To find out if you’re using it:

lsmod | grep acpi_cpufreq

2. You need to get a modified version of your acpi_cpufreq module, one with PHC (processor hardware control) support build in. There are several ways to get this module.

a) You can download a patch or a precompiled module on the official forum and official website and compile it yourself.

You can also download the precompiled modules from the authors’ subversion repository, however these are not updated regularly:

svn co http://phcpatches.googlecode.com/svn/trunk/acpi-cpufreq phcpatches/cpufreq
svn co http://phctool.googlecode.com/svn/trunk/ phctool

Note: To find out what kernel you have open a terminal and type:

uname -r

Mini-Howto for compilation (from Ares Drake thread)

extract the tar from /usr/src to /home/”your-username”/”kernelversion”
download latest patch to /home/”your-username”/”kernelversion”
copy /boot/config-$(uname -r).config to /home/”your-username”/”kernelversion”

cd /home/”your-username”/”kernelversion”
patch -p1 < linux-phc*.patch
make oldconfig
make prepare
make scripts
make M=./arch/x86/kernel/cpu/cpufreq

The finished module should be in /home/”your-username”/”kernelversion”/arch/x86/kernel/cpu/cpufreq
Proceed as if you had downloaded this module with copying it to the right place.  After all is done you can savely remove the folder /home/”your-username”/”kernelversion” and uninstall linux-source to save harddisk space.

REMEMBER: First backup your old module (basically copies it to a new name ending with .old)

sudo cp /lib/modules/`uname -r`/kernel/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.ko /lib/modules/`uname -r`/kernel/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.ko.old

b) Then copy the downloaded file to the right place:

sudo cp acpi-cpufreq.ko /lib/modules/$(uname -r)/kernel/arch/x86/kernel/cpu/cpufreq

So once you know, download the right kernel module from Ares Drake thread at Ubuntuforums.net

Kernel modules are also copiled by the THC crew and available on the main download site as well as on the official forum.

You have to redo the entire Step 2 every time you update your kernel, so you might want to save your downloaded module file, as it might work again after a kernel upgrade, i.e. the version -16 worked with -14 and -15 as well, but not with -17.

3. Reboot. If the module is installed correctly, then look here for phc related files

/sys/devices/system/cpu/cpu0/cpufreq/

One should be like this one (values would be of course different):

12:38 10:30 8:24 6:18

In order to minimize any possibility of data corruption I advise you to run this script from Ubuntu Safe Mode / Recovery mode (choose this at boot menu, then root terminal when prompted). Here you will have a terminal only environment, which also lacks any cpu management module. Remember you are in a root environment, here you may also do system wide damages! Be careful with the commands you type in!

First you have to load acpi_cpufreq:

# modprobe acpi_cpufreq

If you haven’t granted execution to the script before do it now

# chmod u+x linux-phc-optimize.bash

cat /sys/devices/system/cpu/cpu0/cpufreq/phc_controls

Then run the scripts the terminal with

The value before the: stands for the frequency, the later for the voltage.

4. Okay, now we need to find the lowest save voltages. We will use this optimizer script.
Download it then right-click the files, open the permissions tab, and and down at the bottom check the box that says “allow executing the file…”.

It needs cpuburn installed, so you might want to install it in advance with synaptic. If you haven’t done so yet

$ sudo ./linux-phc-optimize.bash

# apt-get install cpuburn

What this scipt does is: It stresses your cpu while lowering the cpu voltage step by step unil your system crashes. Then the script knows what is too low and will stay safely above. The script needs to run once for every frequency step your cpu is capable of, usually around 4-6 times. It will tell you, just run it so often until it tells you finished.

In case you have a dual core CPU it is advisable to run two instances of cpuburn,

first run

cpuburn &

then run the script (which will run the other instance)

NOTICE:
This script will crash your system. Several times. This is normal and intended. No harm to your hardware is to be expected. However in case you have open files and / or mounted filesystems data loss or corruption might occur. So be advised to unmount as many partitions as possible and open as few files as necessary while doing this. After a reset the fsck utility will check your partitions for data corruption so be strongly advised to let that check run!

All this is not going to occour if you run the script from the recovery mode

Second, the script stresses only one cpu core. In case you have a dual core, open a terminal and type “burnMMX” to run a second thread to stress the second core while doing this.

When you’re finished with the script, you will have a text file with the new and optimized frequency : voltage pairs.

5. To use these optimized values, you will need to echo them to /sys/devices/system/cpu/cpu0/cpufreq/phc_controls. An easy way to do it automatically every reboot is to add a line like this:

to your /etc/rc.local file. Of course you have to replace the values with your own. Any second core should automatically use the same voltages.

6. Check if it works:

cat /sys/devices/system/cpu/cpu0/cpufreq/phc_controls

[EN] Power saving optimizations has been updated with some major changes, please have a look at it!

Update!! the duplex printing feature has been implemented for Samsung printers on linux (including ML-2010) with version 2.0.0 of the Samsung drivers (available with Ubuntu Linux Intrepid 8.10).

To ensure you use the latest ones go to  ‘Printer Properties’ in System -> Administration -> Printing and check the ‘Make and Model’ field. To update your drivers simply click on the Change button and confidently follow the wizard.

You will find the option for the two sided printing under the ‘Printer Options’ tab.

An interesting program for non supported printers is GtkPSproc you are welcome to test it and add feedback.

—————————————————————————

Duplex printing [1] is currently available only to mid-high-end printers.
However same goal can be achieved with minimal effort and minimal user interaction also on simplex low-end printers via a software hack.

Procedure:

This has been achieved for example by Samsung windows drivers. These paginates the printing queue so that sheets are printed

1. firstly rotated 180 degrees and filed in reverse order
2. then the driver prompts the user to put printed sheets back into the tray ‘as they are’ (no manual weired rotating and flipping needed)
3. finally printed normally

The resulting is a paginated duplex printed document.

Advantages and Benefits:

With manual duplex printing a wide range of users with low-end printers such as Samsung ML-2010 series are enabled to:

• print documents on both sides of paper
• make professional looking booklets
• lower the usage/waste of paper
• lower the home/office environmental impact

References:

Blueprint: https://blueprints.launchpad.net/system-config-printer/+spec/manual-duplex-printing

Bug report: https://bugs.launchpad.net/ubuntu/+source/system-config-printer/+bug/193088

Ubuntu Brainstorm: http://brainstorm.ubuntu.com/item/3332/

———

[1] http://en.wikipedia.org/wiki/Duplex_printing