Welcome

This is my home in the virtual world, where I write about things that I want to share. The freely available software that I've written as well as some of the photographs I've taken over the years can also be found here. Please use the navigation links on the right if you are looking for something.

Recent articles

1. Chickpea and vegetables stew

   This is a variation on a recipe that I found in a cookbook, because some of the ingredients in that cookbook aren't in season right now.

   The ingredients I used were:

   • one can of chickpeas (400 g)
   • one can of diced tomatoes (400 g)
   • 250 grams of French beans ...

2. Switching to the vim editor

   After having been an emacs user for a long time, I was starting to grow disenchanted with it around version 24. My main problem is that it was starting to get really slow. Not just in starting up, but also in daily use, especially it you kept an instance open ...

3. Making my first EPUB

   Now that I got an EPUB reader, I started looking for a way to make EPUB documents.

   In principle, an EPUB file is a zipfile with a certain layout, as can be seen on the wikipedia page linked above.

   The actual contents are just XHTML, while the metadata files are ...

4. Sony Reader review

   A lot of classic books that are in the public domain because their copyrights have expired (as they are supposed to) are available from Project Gutenberg. Long before e-readers were available I downloaded these books in text or HTML format and read them on my PC. This unfortunately was less ...

5. Filtering a sound recording

   Recently I was listening to an MP3 file of a talk about no-till gardening when I noticed that there was a noticable buzz in the sound. I figured I would try my hand at sound filtering with Python as a learning experience.

   The Python standard library doesn't have a ...

6. Automated local backups

   These days it is commonplace to have hardware or software RAID1, even in common PCs. In previous machines I've used ataraid to implement RAID1.

   The advantage is that every write is recorded on two disks at once, minimizing the chance of data loss. The flip side of the coin ...

7. Updating multiple systems using a pre-built FreeBSD

   Recently I updated my workstation to FreeBSD 9.1-RELEASE-p1. Since my laptop runs the same OS, I wanted to update it without rebuilding the world and kernel locally. I used the folowing steps to accomplish that.

   • Using netcat in combination with tar, the directories /usr/src and /usr/obj were ...

8. Should system backups be compressed?

   Every now and then I make backups of my FreeBSD system's filesystems with the venerable dump program. This is the only program that can capture all features of the UFS filesystem. The filesystems to be backed up are:

   • The root filesystem.
   • The /usr filesystem.
   • The /var filesystem.

   Note

   My ...

9. Fixing squeaky bicycle disk brakes

   The Shimano Deore XT disk brakes on my HP Velotechnik Scorpion trike have always been very noisy when dry. Oddly enough they were much quieter when wet. Over the years I've tried sanding the pads and different detergents and cleaners including strong industrial solvents.

   But only recently I solved ...

10. Updating to FreeBSD 9.1-RELEASE-p1

    There have been some changes in the FreeBSD update process. The csup program has been retired, source code updating is now done with subversion. Since I haven't used that before, I'm documenting the steps that I took here.

    I'm using source updates instead of freebsd-update because I ...