Ahh I see. Unfortunately, it looks like that's the only update available as of now. Also, in my opinion, I don't think your phone will get any further update. You might want to check if there's a Lollipop rom made for your phone.

This is exactly the version i have (OS v 20130918.120942  (295MB) )  That's Android 4.1.2 from sept 2013. However i was looking for a more recent version as Lollipop or even Marchmallow ! I asked Archos service via Mail..here the stupid answer:

Unfortunately we do not have this information.

As soon as there's an available update for your device, you'll receive a notification directly on your smartphone.

Hi Bernard. I check Archos website and found that there's a firmware update for your phone. Check it here to see where the update can be downloaded.