
Recently, during my visits to various online flea markets, I bought a batch of old electronic junk for just a few euros, and there was also this very stylish controller with an Atari-type connector, making it compatible with my Commodore 64 and VIC 20 as well.
It’s in very good cosmetic condition. The plastic probably wasn’t yellowish when it was new 40 years ago, but I’m not one of those obsessed with retrobrighting, so as far as I’m concerned, it’s perfect as it is.
I have a soft spot for electronic devices with transparent plastic cases; in this particular case, you can see the LEDs inside lighting up every time a button is pressed.
It’s not a necessary feature for playing games, but visually, I must say it looks pretty cool. Very flashy!

I wasn't familiar with the last mode. Here's the only information I found about it online from an old Italian magazine (Full text of K-Kappa magazine issue 44):
In decathlon mode, while the top green button is pressed, the joystick reacts as if it's going right, and when it's released, it goes left (very practical, but who still plays Decathlon?)Unfortunately, this switch doesn't lock into position, which makes it very inconvenient if you want to activate the central auto-fire position during a game, since you have to set the lever exactly in the middle, and the function won't activate if it's just a little bit off-center.
In my opinion, it would have been better to have the decathlon mode in the center. This way, it would have been much simpler to switch from normal to auto-fire mode.
If I wanted to, I could make a small modification by swapping a couple of wires, but I think I'll leave the controller as it is. I've always seen the auto-fire option as a bit like cheating!
Once opened, I immediately realize the first problem: one of the two green wires has detached from the PCB (the one towards the bottom).

I desolder all the wires and finally get access to the other side.




I checked them all with the multimeter (in diode test or continuity test mode), and they work perfectly.
I grab my desoldering gun and proceed with the replacement!


The capacitor is 100uF / 16V. According to the table on the ESR meter itself, it should have a maximum ESR of 0.7 ohms.


With the multimeter (forgive me, but I forgot to take a photo), I also checked its capacitance, and it was around 90uF, reasonably within tolerance.
So, the capacitor is okay!
I should have done this after resoldering the wires; in fact, I cleaned it again afterwards.



The second top button, however, uses a different mechanism.
To do this, just put a drop of alcohol on the switch, a small piece of paper between the contacts, close the contact, and slide the paper to wipe away any traces of dirt.



In the worst case, they're rusty, but maybe they're just very dirty.
I'll try cleaning them with the ultrasonic cleaner.
You'll see it often on these pages.

Along with the water, I added a drop of dish soap.



Much better than before!

For this reason, once I assembled the circuit in the case, I realized that the plastic parts of the big red buttons (the action buttons) are keeping the switches pressed down, making them unusable.
However, there's no problem with the switches corresponding to the control lever.



In fact, some commands don't work.
Before proceeding, I need to note which wires correspond to the individual pins of the connector.
It's a very tedious but necessary job.
To do this, I took a small piece of metal wire (one of those leftover when soldering resistors), connected it to the various pins of the connector, and one by one I checked with the tester, in continuity test mode, which wire it corresponded to on the PCB, noting everything down on a post-it.



These cost very little on AliExpress.


Another tedious job, but someone has to do it.

Useful for horizontal scrolling shooters, such as Defender!
Conclusions
In my opinion, this is a well-made, solid controller with good quality plastic, and it definitely deserved a second life.It's a shame about the not-very-useful switch for selecting the game mode, but I'll live with it.
It also seems to be quite rare, given the scarcity of information found online.
I think I did a good job with this restoration, and I certainly enjoyed doing it.
Let's hope the new switches last over time.
bit sparkle
A blog about programming, electronics and old stuff.