Tech Notes, Tips & Reviews

Extending the Life of Pinball Alpha-Numeric Displays

Jan 102018


The glass score display tubes used on most pinball machines have a limited life and will eventually "gas out".  This is not only inconvenient it is now days hard to find replacements and they can be very expensive.

For this reason we should try to extend the life of our displays for as long as possible.  Many of these displays run at high voltages of around +100V DC and -100V DC.  This allows them to be nice and bright when the pinball is being used in an arcade, but these days many of these machines are now installed at home. 

Reducing the voltage by just a small amount will give a dramatic increase in service life.  In this example I will be changing the zener diodes on a Data East 520-5000-00 power supply board. By changing the 100 Volt 1 Watt 1N4764 zener diodes to 91 Volt 1 Watt 1N4763 diodes we will effectively reduce the voltages being delivered to the displays.  On this particular board the diodes in question are D9 and D10.

You can see D9 and D10 highlighted in the image below.  Before changing these the measured voltages were around ±103V DC, after swapping them for 1N4763 the voltages were reduced to ±95V DC.  The difference in the display is barely noticeable.


 It should be noted that if your display is already flickering or faded then it is probably already starting to fail.  In this case changing to a lower voltage may actually make the symptoms worse or may cause it not to display at all.  In this case either your board needs servicing or the displays need replacing.  If you do replace the displays I highly recommend changing the diodes at the same time.

Pinball #89 Globes too bright in Mini-Domes

Jan 072018

undefinedGlobe brightness in a pinball machine tends to be a personal preference and also depends on where the machine is being used.  Most pinball machines were designed to be used in arcades that are usually well lit.  When a pinball machine is used at home the lighting can be very different.  The mini-domes arranged above the playfield on the Data East Simpsons machine were way too bright for my liking even with the standard #89 incandescent globes.  When replaced with #89 LEDs they were slightly brighter again.  There was some improvement when the LEDs matched the same colour as the domes (rather the white) but still too bright.

My solution was to use some sort or filter/diffuser inside the dome.  I ended up using the casings from old fluorescent starters. By cutting them down slightly with a hacksaw they fit snugly over the LED. Then with the dome re-installed the light is nicely diffused and much easier on the eyes.


Here are a few photos to illustrate the process..



Setting Windows File Associations in Wine

May 222012

WineAssocWine Association Creator

When running an application in Wine recently I noticed that if my application wanted to open a Word document or Excel spreadsheet it failed because Office isn't installed in Wine, even though I had LibreOffice installed natively in Linux. The same goes for PDF documents which fail because I don't have Adobe Reader Installed, I have Okular already installed in Linux.

When searching the net for a solution all I came across were registry edits and a couple of command line scripts. So I decided to write a simple application in Qt/C++ to make the process easier.

After downloading WineAssoc simply double click on the file (you may need to make it executable first) or from a console run ./WineAssoc in the directory you downloaded into. You will be presented with a window as shown here in the screenshot. Simply select which file extensions you wish to associate to native Linux applications and then click Add >> to move them to the right hand column. When you have selected all the required types, click Apply. Note that WineAssoc honours the WINEPREFIX setting and will prompt for confirmation before proceeding.

The extension list is populated using Linux config files, with a few extras added in. If by chance your extension is not shown you can start WineAssoc from the console specifying extra extensions manually. For example ./WineAssoc abc def would add abc & def to the association list. You can also hover your mouse over an extension type to show what programs are associated to that type.

The program should run on most Linux systems that have Qt 4.8 or later. Please let me know if you have problems with a particular distro and Ill try to look into it.

 Download WineAssoc using the link below:

Find this utility useful? Leave a comment or consider a purchase from our website.


WineAssoc is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.

MinAmp – Pandora Music Player

May 142011

undefinedMinAmp for Pandora

Introducing MinAmp for Pandora (and desktop Linux), a minimal music player mainly designed for use as a car player. This is my first application for the Pandora. Actually it’s my first C++/SDL application. Feed free to provide feedback on this application, you can also suggest changes and features requests.

On first run MinAmp will look for the Music directory on your mounted SD cards (either “music” or “Music”). If running on desktop Linux it will look for music or Music in your home directory. If this fails to find your music for some reason you can manually edit the "minamp.conf" file but hopefully this won’t be necessary in most cases.

I have assumed that your music directory is organised so that each artist is in its own directory with each album below that in it’s own directory. In each Album directory you can have a "cover.jpg" with the album cover art. If this doesn’t suit you I’m sorry, I may entertain alternate layouts but may need some incentive ;)

At present I support the MP3, OGG & FLAC file formats, I tried WMA but track length and reliability issues made me take it out. Audio output can be sent to the default, digital (SPDIF) or Bluetooth outputs. Bluetooth on the Pandora may require modifying the .asoundrc file and has had limited testing (See the forums).


  • The touchscreen is active, and hopefully fairly obvious in operation.
  • Click an Album cover to play that album.
  • Click on the progress bar to jump within the current track.
  • Shoulder buttons are Previous/Next track, very sensitive at the moment (probably not good for jogging but works for cycling).
  • Press a letter “a” to “z” to seek to the albums that start with that letter (ie “c” for Coldplay).
  • Left/Right Arrows (Nub) to move the album list left and right.
  • Up/Down Arrows (Nub) are Previous/Next track.
  • Enter plays the Album in the center of the list.
  • ESC exits the player (Also clicking on the X on the screen).
  • HOME (or “A” button on Pandora) goes to beginning of Album List.
  • END (or “B” button on Pandora) goes to end of Album List.
  • SPACE is used to pause or un-pause the current track.
  • BACKSPACE/PAGEUP (or “Y” button on Pandora) goes to previous track.
  • PAGEDOWN (or “X” button on Pandora) goes to next track
  • Numbers keys 0-9 will select tracks (eg Press 1 for track 1 and then again for track 11)

If you exit the player while it is playing a track, on next use it will try to start from the same track.

Possible Future Enhancements (Keeping in mind it is supposed to be a minimal player):

  • Random Play
  • Album Queue
  • Options to make Shoulder buttons less sensitive, (Maybe double click or hold for next Album)
  • Fix some issues with the resume track function.

I still consider this software to be an Alpha release, features and functionality may be changed, added or removed. Enjoy and don’t hesitate to provide feedback and comments below.

To download MinAmp for the Pandora please go to the Pandora Repo (and don’t forget to vote ;) )

For Linux desktop/netbooks you can download the 32 and 64 bit versions here (Sorry no Windows version yet, may or may not happen)…

MinAmp 0.31 for 32 Bit Linux (x86)

MinAmp 0.31 for 64 Bit Linux (x86_64)

MinAmp 0.31 for 32/64 Bit Linux (Manual Install)



MinAmp is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.


Installing Dropbox on Mandriva 2010.2 KDE

Apr 042011

undefinedDropbox is a great idea, and has Linux support, the only problem is that it currently only supports the Nautilus file manager (Gnome). I thought this wouldn’t be such a problem so I loaded it using "urpmi dropbox" in the console or you could use “Install & Remove Software”. The Dropbox icon can then be found on the “Internet” menu.

It all appeared to work perfectly, Dropbox downloaded its binary file and then I entered my account details and all was good. (Note: You may need to start Dropbox a second time before it downloads the binary, not sure why that was).

Dropbox places an icon in the system tray, clicking on it opens Nautilus and shows you your files. You can add/update and edit your files and it all just works. I thought OK I’ll just use Nautilus for Dropbox and all is good.

Then I plugged in my USB stick and noticed that the Device Notifier was no longer working properly, it was now calling Nautilus instead of Dolphin and not opening the USB devices properly. That wouldn’t do, so this is how I fixed it…

First I removed the Dropbox and Nautilus RPMs using “urpme nautilus-dropbox nautilus gnome-desktop-common libgnome-desktop-2_17 libexempi3″ in the console. This leaves the dropboxd binary file that was downloaded when I ran Dropbox so I can just use that to do what I need. Next from the menu go to “Tools->System Tools->Configure Your Desktop”, click the “Advanced” tab and then double click the “AutoStart” icon. You’ll probably find like I did that the Dropbox entry is still there (If not you’ll need to create one). Click on the Dropbox entry and then click the Properties button, on the Application tab replace the Dropbox command which will be something like “dropbox start -i” with “~/.dropbox-dist/dropboxd” (without the quotes). Logout and Login again.

Now when I start KDE the Dropbox icon automatically shows up in the system tray and even better if you click it now it opens Dolphin and not Nautilus. My Device Notifier also returned to normal. All is good :)



Setting up a C++ Development Environment on the Pandora

Jun 242010

undefinedI wanted to set up the Pandora so I could develop C++ programs directly on the unit rather than using a cross compiler.  I am also installing the SDL & OpenGL ES libraries. Until a PND package is produced this is what I have done to install the development libraries. You need to use a terminal to issue the following commands and then either issue these commands prefixed by sudo or login as root using su.

opkg update

Update is important to do first to make sure the package lists are up to date. Under no circumstances do a opkg upgrade, trust me on this. If you do be ready to do a firmware re-flash.

opkg install gcc gcc-symlinks gcc-doc make make-dev binutils-dev
opkg install cpp cpp-symlinks
opkg install g++ g++-symlinks libstdc++-dev
opkg install libgles-omap3-dev
opkg install libsdl-1.2-dev libsdl-gfx-dev libsdl-image-1.2-dev libsdl-net-1.2-dev libsdl-ttf-2.0-dev

OK, this is the tricky one, OpenPandora have patched the libsdl-mixer library, so there is no equivalent -dev library, for the mean time I am forcing the installation of the Angstrom library, you will notice the nodeps flag. So far I haven't seen any problems with doing this, your mileage may vary. I will be coding an application that uses sound (portable music player) so we'll see how it goes.

opkg nodeps install libsdl-mixer-1.2-dev

You can write your code using nano or vi in the console or use the GUI application Mousepad. I suggest creating a directory for programming on your SD card. Then in a console you can compile and run your applications. In a follow up post I will show how to write a Hello World program on the Pandora using some SDL and C++.

Have Fun :)