The strangest slide rule in the universe

8 August 2020

Collecting slide rules, this is about the strangest I encountered. No scales, no markings, with a duplex cursor, perfectly fitting in an original Faber-Castell transparent box.

Browsing the ISRM website, the body is alike the 52/8x series, but they have different cursors — mostly with multiple hairlines. This ’52/8x’ only has one on each side.

It is the second one I encountered on a market place on the internet, so there must be more of it. Wonder what it’s purpose might be…

Don’t get Locked Out on your Linux machine!

19 July 2014

A lot of us will share a Linux machine with other people in the house — at least I do. Over here there are several user accounts on one happy Linux ‘family box’. But sometimes sharing a machine is frustrating, especially when a housemate leaves the keyboard with a locked account just when you want to start things up for yourself. Sharing passwords is a bad idea, so it looks like you’ll just have to wait.

The combination of <ctrl> + <alt> + <Fn> will take you to one of the six built in terminals, where Fn stands for the function keys 1 to 6. F1 is reserved for the default environment at startup of your computer.

And right here is the solution when you are locked out by another user:

  1. press <ctrl> + <alt> + <F2> (or one of the others, as long as it is not F1);
  2. login with your own account, you’ll get a full screen terminal;
  3. type $ startx and hit <enter> (the $ prompt is already there);
  4. and you’ll see your own environment in full graphical glory.

Finished? Just logout or lock your account (or not), and press <ctrl> + <alt> + <F1> to get back to your housemates’ locked account. If you like to come back and you didn’t log out, <ctrl> + <alt> + <F2> just brings back to where you where.

I’m just happy to post a nifty trick instead of reacting to challenges ;-)

GPL Your Children!

3 June 2014

Recently my family was discussing the working of patents at the kitchen table. Patents on ideas and objects made are to protect them from being used, copied or changed by others without you wanting or knowing. Besides, it’s your idea after all and people should pay you as the super smart inventor. When I entered the discussion trying to explain the benefits of using GPL, my status as ‘Linux Freak‘ was acknowledged. So far.

Next time I’d better use the LEGO metaphor.

Every weekend we lay on the floor building whatever comes to mind with LEGO. With over 40 years collecting we not only have a huge stack of pieces, but also I have a very rich experience in inventing and building vehicles, airplanes and even my own version of an R2D2 with rotating head and adjustable legs.

r2d2And every time me and my children are building they ask me whether they can

  • have the <device_name> I built to play with;
  • modify the <device_name> into something different / better / faster;
  • use parts of the <device_name> to fit to their inventions.

Being Open Source minded I like them using my invention to accumulate with theirs. Most of my LEGO builds are instantly GPL-led.

But what happens when I just say ‘No‘ to them changing the order, form or colour of my buildings blocks and ripping off any modules? Well, they quit playing with me because in their opinion I don’t foster their creativity. And they are right indeed.

Now the link to Open Source software, city planning, […] and education is obvious. We need to share to make things greater and with better fit for whatever human need. Not only in coding, but also in organizing things, building houses and in a spiritual sense. Thesis – Antithesis – Synthesis is practised with enough eyeballs makes things grow faster, with better fit and chase bugs away easier. Besides: we wouldn’t be able to travel though time if Einstein kept his Theory of Relativity all to himself.

But how do we convince our junior citizens and beginning coders to share their ideas or code and have them mix and accumulate with the inventions of others?

By just playing with them and sharing the mindset of the GPL.


11 May 2014

For years I tried Mindfulness, Meditation and Zen, but it came a lot faster using terminal and typing:

# yum install enlightenment

Off course there is a huge difference with becoming Enlightened in a way that frees your soul, but working with a computer this version of Enlightenment comes a good way.

In February I was asked to write an article for on Desktop Environments. Being a Social Sciences Nerd and not that bald a coder, a Desktop Environment for me is the prime interaction between human and machine. Distro’s are just a bundle of software and routines, and the .deb/.rpm discussion is useless in an end user’s perspective — it just installs the updates and removes the leaves.

Writing this article I surfed the Net and together with my own experience I compiled a story recommending a few of the widely known desktops. Until someone pointed me at Enlightenment. In fact ‘e’ is a kind of window manager and not a complete Desktop Environment. For a while I tried Enlightenment besides the Fedora 20 LXDE on my main machine.

Soon I discovered and liked the cleanness and responsiveness of ‘e’. LXDE is very swift because it doen’t provide all the eye candy that comes with the larger Desktop Environments. In previous years I developed my own set of key-bindings and routines. Enlightenment first came a bit of a shock: all the shortcuts I was used to didn’t work and I had to search for the usual accents (Dutch uses quite a lot of them) and the € sign. Here the explanation on the Bodhi Linux Documentation came handy and provided the basic needs.

But then the eye candy, and I mean Eye Candy! Enlightenment is not only more responsive than LXDE, but it also provides a beautiful surrounding to work in — and at no CPU-cost!

Now Enlightenment was planned for Fedora 19 and provided in the default repo with Fedora 20. But the Fedora way, some things are Bleedin’ Edge where other things come a bit behind. The beauty of Linux is that you are never alone with your questions and the Copr Project of Fedora provides an up to date repository for Enlightenment in Fedora. The shift from the basic 0.17 to 0.18.5 was huge! Everything works much better and in the last weeks I had no crashes. Great!

Terminology with preview

But ‘e’ has more than different looks! Enlightenments own terminal Terminology comes with a few special commands: often used regular Linux/Unix commands but with a leading ‘ty’. This way you can preview pictures and pdf’s with the ‘ls’ command by using ‘tyls’. Having a full view in terminal just type ‘tycat <file_name>’ and you get a full colour picture in terminal. You can also click on the preview image in the ‘tyls’ output or type ‘typop <file_name>’ — in both ways you get a pop-up with the chosen picture. Just surf around to discover the tricks for these nifty features, since the documentation on Enlightenment and its parts is more technical than end user orientated.

Maybe not that useful IYHO, but it is Fun and great to work with!

Monitor battery discharge in Linux

25 August 2013

I wondered how long the battery of my Acer Aspire One A110-BW would make me ‘socket-less’. Monitoring by hand is not very practical, so I started to bash around and did some low level coding.

The result is a simple script that monitors the discharging of a laptop battery. It starts with reporting basic info on the condition of the battery. Every 60 seconds the power status is written to the same file. The file and its lines have detailed date and time stamps to compare subsequent reports.

The bash script needs acpi installed, it should be in the repo of any Linux distro. You can run it as a regular user. Needless to say that the laptop should run on battery power…

[user@mybox ~]$ ( date && acpi -V | grep Battery ) > `date +%y%m%d_%Hh%M`_batterylog.txt; sleep 60; while x=0; do (( date && acpi -V | grep Discharging) ; sleep 60 ); done >> `date +%y%m%d_%Hh%M`_batterylog.txt

[changed the %H:M to %Hh%M in the output filename as the colon ‘:’ frustrates filemanagers and other CLI handling]

Bash spreads the output of two subsequent commands (here <date && acpi>) over two lines. I tried <echo -n> to make one line every minute but with no succes yet–it’s something I have to work on. I set monitoring pace to one minute (60 secs) to get detailed reports.

Use this script if you like. If you make interesting improvements I’d like to hear from you!

Rooting my Droid

2 August 2013

Last May I defenately decided to root my Samsung Galaxy 4.2 WiFi. The good news is that it is running flawlessly since! Since buying the device rooting had my interest, but there was no real need to go on this journey. What if it didn’t work and I brick my favorite pocket computer? Could I go back do default? And for rooting: can I find the right images and instructions for rooting a not so much used Android?

After failing to update TalkBack I was definately determined to root my tool. “TalkBack is an Accessibility Service that helps blind and vision-impaired users interact with their devices more easily.” reading the GOOG playstore. It comes pre installed on the Galaxy and I never used it, I have excellent eyevision. But the update required deleting the previous version first before installing the fresh version. Some apps do, no problem. In the case of TalkBack however delete failed because as a Dumb End User of my Droid I had no permissions to delete system apps. For the least this permissions-policy would annoy me with Please-Update-TalkBack messages until the end of time.

On a more fundamental level IMHO Freedom of Choice is a right for all of us. I like to choose the tools I like in the way that suits me best, likewise on my Android. So away with GOOG restrictions on my privately owned pocked device.

How-To in a Human perspective

The technical How-To’s are provided in the links

But how to proceed? After all the Galaxy WiFi is not a very popular model and skilled coders let it be for a long time for the understandable reasons. Last May however I discovered that there were some posts on the xda-developers forum for the Samsung Galaxy Player 4.2. YESSS! I also looked for CyanogenMod for even more freedom, but with no succes on my Galaxy WiFi. Replicant is a parallel initiative.

Meanwhile I convinced myself that rooting my Droid was no different from trying and full use of Linux. Back in 2009 I discovered Linux but it took a while to convince myself that changing or modifying an operating system is quite safe. After all many people did it before and explore new worlds. I don’t say it always is easy, but in fact there are hardly any risks. Development is all about doing things a different way, otherwise you’ll stick up with the old (and often annoying) results. Reading all the right stuff, downloading the proper software and images and backup all your stuff you want to keep.

First I had do find out what version of the Galaxy I had on the table. Strangely enough I don’t own an International version but a North American one. Don’t ask me why these are regulary sold in the Netherlands. I only know some political reasons my country seems to be the 51st State ;-) International and North American devices have different ROM. The XDA forum provides both as well as the stock factoryfs ROM. So in case I didn’t like the result I was able to go back to ‘normal mode’.

Given Enough Eyeballs, Every Problem is Superficial

The International ‘rooting page’ on XDA has a well written how-to providing all neccesary steps. If you like to root your Droid be sute to read and double read these instructions until you know what you’re going to do!

To do the job I had to install ADB to connect and send commands to the Android from my Linux computer. Luckily I discovered a page that instructed only to install specific parts and not the entire set of Android Developer Tools ADT. Lots of this stuff you don’t need when only rooting your Droid. Now ADB told me to install Oracle Java instead of OpenJDK I use in Fedora. Freeing your Droid from GOOG only with the aid of proprietary software? IMHO both companies are kind’o crooky… Besides Java is and ongoing security risk. For the very same Java & Security reasons I use VirtualBox (you’re right, again Oracle) with Linux Mint. This provided an excellent platform to do all the neccesary ‘java-stuff’ in a relatively safe environment–which sands for: not affecting my main Fedora system.

Final part in rooting is flashing the ROM on my Samsung Galaxy. Where Odin is used in Windows environments to do the job, Heimdall is a cross platform alternative for Linux. In past years I more and more learned to appreciate command line operations, but Heimdall also has a graphical shell (which didn’t work for me so I gained full control with CLI). Heimdall was in the Fedora repository. The basic use for flashing with Odin or Heimdall are quite the same.

So far so good, I managed quite well to put the de-googelized ROM on my Droid. Final touch was restoring the WiFi files. It is a common problem that WiFi only works with the original files put back in place.

Up and running!

Now back to where all this fuzz started–to get rid of pre installed software. Although GOOG doesn’t provide us with default root access as common on proper operating systems, the playstore has plenty of apps to manage root functionality. Again this took some late night surfing to decide between the good, bad and ugly. Do I like this app? Why on earth does it want to control networks and camera–the usual suspicious questions. Rootappdelete made the difference for me. I found well written explanations of the working of this app. Great suggestion and feature of this app was first to freeze unwanted apps and see how your Droids performs. Freezing puts the app completely out of work, it only doesn’t delete it in case of trouble or regret. Rootappdelete also colorizes its advice wether it’s safe to put things away and when such can cause nasty problems.

For two and a half months I run my rooted Droid without any trouble. Most of the pre installed and adviced ‘safe to remove’ apps are taken out of order (some Samsung Smart View bluntly refuses). Thanks to the exellent work of hard(er) core coders I was able to change things the way that suits me best and regain my Digital Freedom. This really is something great: people sharing their knowledge, just because they can help others with it. Many Thanks!

There are noticabe less reminders to update things I don’t use and no more of the TalkBack-like issues. One of these days I will permanently delete the apps I put in the freezer to free some memory, also one of the big advantages of rooting. My rooted Droid now has the possibilities to connect to other computers in my home network. Fun–just because it is possible :-) Soon I’ll get this ssh-thing working to out of pocket (literally) and remotely kill these huge and bandwidth consuming media streams of my youngsters. Indeed, a rooted Android is all about getting back control ;-)

Anton Pieck is still alive!

15 January 2013


This evening I took this Anton Pieck style winterish picture of one of the building complex he designed in Drunen (NL). The pict was edited with GIMP comic filter.

1 January 2013


My old website

16 November 2012

Years ago I started a website dedicated to my motorcycling–travelling, safety, maintenance. For years I was very active maintaining, in later years I didn’t change a thing to it. Still the website in Dutch and English seems to be attractive to visitors. Almost every day one or two people browse around. I think this is amazing!

Over the years I received wonderful emails from all over the world. Not only to say thank you but also asking for help–on secret riding trails, spare parts for and aged Montesa or just and invitaion to pass by when I would visit Canada or Honkong. I’m sorry, I never got off this continent… Back in 1998 I even got a live visitor from the States and I still have good memories chatting, talking Beemer and eating Maryland spiced shrimps the next days!

Once in a while I think of deleting the site. The type of bike is hardly seen on the road anymore, I never converted Dutch guilders to euros and IMO obsolete stuff should be deleted from the net. But really deleting the site? No, I can’t do it. I can’t because there are still people out there that like to read my writings, maybe copy some of my tours in the Belgian Ardennes, France and Spain. The second reason is I started the site back in 1995 and still attracts people.

And I think it is fun to have built a website in the 36k6 modem era that still is on the first page of a search engine when you look for a BMW F650–sweet memory…

When you like please visit my site and see for yourself!

How to Coose the Right Linux?

9 October 2012

Starting with Linux can be quite a puzzle. There is so much to choose from that new users might get lost. Here I want to help choosing the right sort of Linux so that you actually can start using and appreciating it. I won’t get into the discussion about what distribution (Mint, Ubuntu, Fedora, OpenSuse, etc, see is best because that is a matter of taste.

Deciding what sort of Linux you can use depends on your hardware and the things you want to do with your computer. Doing resource demanding graphical stuff on a somewhat aged computer will get you frustrated. Even on Linux, hardware will set limitations, even when Linux will perform much better on the same machine than with Windows.


Now Linux comes with different types of desktops. Compare it to the different look and feel of Windows XP, 7, 3.11 or Mac OS. These different desktops — the look and feel — share basic functionality but differ in needed hardware resources. Linux basically comes with four types of desktops that you can choose from depending on your hardware:

  • LXDE — bare basic desktop for computers with limited hardware, or limited needed hardware for speeding up the user environment;
  • XFCE — basic desktop for computers with standard but modest hardware;
  • MATE — extended desktop for regular computers;
  • Gnome3, KDE, Unity — desktop for more powerful computers, mainly on the graphical side to to offer a modern, visual attractive working environment.

The beautiful thing about Linux is that you can add almost any software to any of these desktops. So choosing a light desktop like LXDE still makes it possible to use a more demanding graphical program like GIMP. Every mainstream Linux distribution comes with a program to add and remove software that will install all needed resources.

Now hardware requirements differ between desktops and distributions. is a good starting point browse do the site of a specific distribution and find some requirements.

Try it!

A different way to see if your computer can run the Linux desktop of your choice is using a Live image of Linux. Most distributions offer downloading a .iso file that you easily can put on a CD or — more practical — a USB stick. This way you can test drive Linux, see how it performs and what it’s like before installing. The great thing is that it will not change anything on your hard disk when only using the Live image.

With unetbootin you can make such a LiveUSB on the fly. Unetbootin comes with pre installed links to several Linux distributions, but it isn’t possible to choose a different desktop with each distro. Luckily unetbootin enables you to select a downloaded .iso file on your harddisk. Instructions for the use of unetbootin and starting Linux from it are given on the site.

After using the LiveUSB Linux version you can choose to install it on your computer. Some distributions ask if you want a dual boot system so you can choose which operating system you want to use on your computer. You also can choose to wipe out all and start using Linux in future. The choice is up to you, but don’t forget to back-up your data before installing Linux on your computer!

I also wrote an article on choosing the right Linux desktop for You can read it here.