27 September 2015

google anniversary doodle

Google 17th anniversary doodle showcases lego cabinet of the first google server at Stanford:

13 September 2015

Astah: fast modeling

Astah (formerly Jude) is a uml tool with a free community edition. The community edition is only for non-commercial use and lacks some important features that are in the paying (but affordable) pro edition, but it is pretty usable.
Astah works very well, I only have some minor remarks about the interface:

  • did not find a way to make an element uselectable (e.g. when you do not want to multiselect all elements in a package, but not the package itself), like you can in Enterprise Architect.
  • you easily select sub-elements when you want to select e.g. a class
Here is a page with some tips for fast modeling from Astah, and a link with keyboard shortcut.
Some more tips
  • Association classes: right click on an association, choose convert to association class 
Sequence diagram modeling does not have the same level of perfectionb in v7.0:
  • Astah is in message draw mode, even when not appropriate (if you misclick you add an unwanted message)
  • not easy to add methods from diagram to existing classes
  • no automatic generation of communication diagrams from sequence diagrams (and vice versa) 
  • unlike sequence diagrams communication diagrams do not
    • prompt to add new classes
    • support iterations

5 September 2015

model translation dictionary

Speaking in tongues: Nice translation dictionary from one modeling notation to another by Scott Ambler

3 September 2015

epf composer installation

You can find an OpenUp Wiki at the epf site. Any team member participating in the Unified Process project can use the wiki to find guidelines, templates etc to participate in the process.
Whatever process you want to use, you probably want to customise the process to the way you apply it at your company.
The epf (Eclipse Process Framework) composer is an Eclipse based standalone application, which allows you to build your own version of OpenUp or another software development process (e.g. Scrum) you use.

The Getting Started section of the epf site has a fine installation guide, though it's a tad out of sync with the site itself.
Here are the steps I  followed to get it running:

  1. Download the composer from http://www.eclipse.org/epf/downloads/tool/tool_downloads.php
    1.  I took the latest version ( at this moment), chose the download for my platform and extracted the zip to disk.
  2.  Go in to the installation directory and run epf.exe
  3. Download the epf practices from http://www.eclipse.org/epf/downloads/praclib/praclib_downloads.php
    1. For openup (or to roll your own stuff) you just take the EPF practices library. Starting libraries for Scrum and XP are also present here, while at other sites you'll find other templates (here's one for TOGAF).
    2. Follow the instructions at the bottom of  the page
      1. extract the zip file to disk
      2. In your running epf application choose File->Open->Medhod Library
      3. Browse to the directory where you unzipped the library select it and click OK, then click Finish
  4. In the Window menu, Open the Authoring or the Browsing perspective, depending on what you want to do
  6. Select your software process
  8. Customise your process
Follow the tutorial section in the manual. There's a preview to see how the generated process page will look and configuration->publish will publish the customised process site.

22 August 2015

Canon pixma mp510 ink absorber almost full / Canon pixma mp510 absorptiekussen bijna vol

IMy printer showed me this error message: Canon pixma mp510 ink absorber almost full. Please contact the service center.
Here's how I dealt with it:

What is the problem? 

Your printer performs head cleaning by forcing ink through the heads to remove dirt. This ink goes into the waste ink tank, which fills up.
Your printer does not really measure this, but when the page printing counter goes over a threshold it displays this message. You can press OK to make the message go away, but when the counter goes over a second threshold, the message will become: "ink absorber full" and you cannot print anymore.

Contacting the service center will cost you more than a new printer, so basically this message says: this printer is designed to fail, buy a new printer.

Option: replacing the print absorber

If you want to play "self-service" center, you can find the service center manual, with all instructions here. Here's the manual section on partial replacement of the main absorber:
I did not actually try this, but google says you can try to extend the life of your absorber pads by washing, drying and putting them back.

Resetting the counter

Next you need to reset the counter.
More often then not, the waste thank is not full at all, so you can risk just resetting the counter.
Here be dragons: when the tank really fills up, the printer might spill quite some ink!

I did not succeed resetting the counter with the instructions in the service manual (go into service mode, press reset four times, press power).

However I had success with this method from tricks-collections (actually for mp520):
  1. Switch printer off
  2. Press OK/BW copy/RESET simultaneously (1/2/3 in picture below)
  3. Press on/off (button 4) while keeping the above buttons pressed.
  4. When printer is on, release buttons 1/2/3
  5. This might actually be enough, but just to be sure I pressed buttons 1/2/3 while i switched the printer off again.

19 August 2015

Java 9 JShell

Jshell (developed in project Kulla) is a java shell allowing you to type java instructions at the shell prompt and have them executed.

  • if jshell detects a complete statement even without a closing semicolon
  • you can type an expression which will be evaluated 
-> 2 + 2
| Expression value is: 4
| assigned to temporary variable $1 of type int
  • you are not obliged to catch exceptions
  • you can save and load your command history
  • you can use methods and references that will only be defined later
-> double volume(double radius) {
>> return 4.0 / 3.0 * PI * cube(radius);
>> }
| Added method volume, however, it cannot be invoked until method cube(double), and variable PI
are declared
  • you can list current variables, methods...
  •  tab completion as you type
Here's a small tutorial.

9 August 2015

Windows 10 upgrade: login fails

After upgrading to windows 10 my password was not accepted !?
Issue: Windows had changed my default keyboard layout to US/Eng, which did not match my keyboard.
This is a setting you can change in the right bottom corner of the login screen, issue solved:

Some people also use their keyboard driver, the on-screen keyboard can help here: