Sounds like good case of building a small device that will ensure uninterrupted supply to the real time clock. This would have to be done before PSN goes out so that the device can live indefinitely (assuming the batteries work, the console does not need servicing, and no other problem is discovered).
I'm willing to bet that all you would have to do is supply AC power to the system while you pop the old battery from its socket and replace it with a fresh one. I can't imagine a design in which the battery would be required while powered up.
But now I think you can easily replace the battery without interrupting supply. Just solder two wires, connect additional battery and then replace the old one with a new one. Nothing extra necessary.
What Sony should do is when they turn off the servers for PS4 they will put a final update that disables all this problematic checks/features.
Now legally if I bought a game digitally could Sony refuse to offer it to me in 25 years because they can't bother to run some servers anymore? The PS3 announcement specifies that you can still download your games, only purchasing new stuff is no longer supported - which honestly feels weird , why not let people publish small indie games to PS3 too, is it hat extremely expensive to maintain those servers? Is it because of technical issues or is a people issue.
That would be a good opportunity for a class action lawsuit. They should normally release a software update to allow users play their games without a PSN connection.
Why? At least in the US it's unlikely anything could happen. They'll say the EULAs explicitly say you are licencing the temporary right to play the game and that's it.
Yes. A lot of external clock/calendar chips use a small amount of CMOS RAM to retain the registers. The objective is very low power consumption when the main power bus is off and the device is drawing off of battery or capacitor.
A common part I use is the Epson PCF8563, for example.
Now the PS4 doesn't seem to have an external chip from the teardowns I've seen. And the term "CMOS Battery" makes no sense other than shorthand for "battery that backs up CMOS memory".
But I'd wager the gates on the custom Sony silicon responsible for keeping time are CMOS or similar technology to minimize power when disconnected from mains (and how often is that? I'm curious what their design criteria is for that).
These systems were not designed to last. Which is why I am a member of the PC Master race. I upgrade my PC to specs above video game consoles and use Steam for my games. My PC is a Steam Machine.
You can find Steam cracks for most popular games on torrent sites right now.
So, realistically someone would make a tool to do this automatically (not done now because API changes quickly, which is not an issue at EOL).
The larger issue is multiplayer servers run by Valve. Some games allow you to run a server and connect to arbitrary servers, most do not. Those are going to be somewhat unplayable without explicit action from Valve.
I used to pirate games until Steam made them affordable and solved the lost CD/DVD issues. So I bought some games for my friends to make up for my past piracy of those games.
Although multiplayer games are pretty much all wrapped up in proprietary systems like Steam, there are significant DRM-free content libraries on GOG and itch.io.