Enable the TRIM command on Mountain Lion for SSD drives

To know if TRIM is enabled for a particular drive, open “System Profiler” and search for the “TRIM enable” information in the “Serial ATA sub-tree”. If TRIM is not enabled,

Read More

Building a Prusa Mendel Iteration 2 3D Printer

It is not obvious to choose and get a 3D printer. There is quite a lot a choices on the market which can be divided in two categories: pre-assembled and

Read More

Ralink RT5572 based WiFi Usb Dongle setup on Ubuntu 12.04

The WiFi USB dongles based on the newest RT5572 chip set do not work out of the box on Ubuntu.  Unex DNUR-V72, D-Link DWA-160 Rev B and TP-Link TL-WDN3200 dongles are

Read More

2.4 GHz WiFi channels

Channel Center Frequency (GHz) 1 2.412 2 2.417 3 2.422 4 2.427 5 2.432 6 2.437 7 2.442 8 2.447 9 2.452 10 2.457 11 2.462 12 2.467 13 2.472

Read More

Recording a terminal session under Linux

It is possible to record a terminal session under Linux with ttyrec. It also records vi, emacs, etc. sessions. Fisrt, install ttyrec sudo apt-get install ttyrec To start recording a

Read More

A step by step guide to setup a Bluetooth keyboard and mouse on the Raspberry PI

A lot of people is having problem setting up a Bluetooth keyboard and mouse on the Raspberry PI. Things get more complicated when your wired keyboard or mouse does not

Read More

Initializing A Wireless Connection At Boot Time

You can initialize your Raspberry PI wireless connection automatically at boot time if the instructions given in a previous post entitled How To Setup A Protected Wireless Connection Via The

Read More

How To Setup A Protected Wireless Connection Via the Command-Line

Setting up a wireless connection via the command line may vary depending on the USB Wireless Interface you are using. These instructions also work for the Raspberry PI running Wheezy.

Read More

Masquerading or replacing outgoing SMTP email address with Postfix

Postfix can replace an outgoing email address by another one. To do so, you must perform these steps: Add in /etc/postfix/main.cf the following line smtp_generic_maps = hash:/etc/postfix/generic_maps Add in hash:/etc/postfix/generic_maps a

Read More

Create an ext3 or an ext4 partition without a journal

Most of the time, having a journal for ext3 and ext4 partitions is pretty useful. Nevertheless, you can prevent creating a journal by adding the option ^has_journal. For example: mkfs

Read More

Initializing a brand new disk with “parted”

“parted” is a replacement for “fdisk” of Linux.  It can handle disks larger than 2 TB.  Issue this command to launch “parted” where /dev/sdL is the disk you want to

Read More

How to download Android source code

Source code of Android can be downloaded by following these steps: $ mkdir ~/bin $ PATH=~/bin:$PATH $ curl https://dl-ssl.google.com/dl/googlesource/git-repo/repo > ~/bin/repo $ chmod a+x ~/bin/repo $ mkdir WORKING_DIRECTORY $ cd

Read More

Installing the Android Development Environment for Windows 7

This post lists the main steps in order to install an Android development environment for Windows 7.  The developement environment relies on Eclipse.  Download a JDK (7u3)  from the following

Read More

How to unmount an encrypted partition?

Unmount the partition umount /mnt Unmap the partition cryptsetup luksClose securebackup

Read More

How to mount an encrypted partition?

Map the partition cryptsetup luksOpen /dev/sdXN securebackup Mount the partition mount /dev/mapper/securebackup /mnt

Read More

How to setup partition encryption?

To setup partition encryption on Ubuntu, perform the following steps: Install the required software apt-get install cryptsetup For more security, erase the partition you want to encrypt with one of

Read More

How to backup and restore Windows 7 activation files

It is possible to backup and restore the activation status of Windows 7 Backing up the activation files To backup the activation status, backup the following files. Administrator access rights

Read More

How to use the loop device on Unix?

The loop device on Unix lets access a file as a block device.  Disks are block devices.  So, it is possible to use a file as a disk.  The first

Read More

How to control the brightness of the display from command line?

You can set the brightness of the display by issuing this command within a shell echo 3 > /sys/class/backlight/acpi_video0/brightness where 3 is the brightness level. Its value is from 0

Read More

How to restore the normal scroll bars in Ubuntu 11?

Simply create a file named /etc/X11/Xsession.d/80overlayscrollbars and put into it the following line: export LIBOVERLAY_SCROLLBAR=0 or simply execute the following command echo “export LIBOVERLAY_SCROLLBAR=0” > /etc/X11/Xsession.d/80overlayscrollbars You need to do

Read More