Honest question, not a challenge: In what way will this improve preservation of PS2 games? My impression was that PS2 emulation was already solved, which I mention precisely to invoke Cunningham's Law. What PS2 things don't work right now because this chip hadn't been cracked?

The problem with game discs is that they rot. Some of them rot faster than others, but all of them shall eventually rot.

The problem with hardware is that it is scarce, and ultimately dies.

The problem with emulators is that they emulate. We can work to make it the same, but it is never going to be the same.

Even if the math all maths just like they did (bugs and all), and it takes precisely as long, and it shows up precisely at the same time in the same places as it did on the original hardware...and even when things like input latency are nailed down to nanosecond accuracy and the clocks are all just dead-nuts on: The code may run the same way, but the system is still not the same.

Part of the reason it's not the same is we haven't even touched the analog components yet and all and all of the things they do, whether amazing or ugly. (And no, improving the analog bits through simplification is not necessarily the sane goal at all. Improvement and emulation are different targets.)

Emulation is useful. It's great, actually. Right now, a person can think about that old PS2 they used to have and get started with playing some of their favorite games yet this afternoon. That's awesome.

But preservation, as an effort to keep old hardware to keep working as time marches on? That's a wonderful thing in its own right. The better we understand the old hardware, the more-able we are to preserve it and keep it running.

Getting past the layers of deliberate fuckery helps us to better understand what goes on behind the curtain, and that has now been achieved.

My guess (not involved with PS2 emulation specifically at all) is that this will improve low-level emulation.

So things like making a clone of the hardware with an FPGA, making emulators cycle-accurate, removing game-specific hacks that are no longer needed due to more accurate emulation, and achieving 100% bug-for-bug compatibility with original hardware.

I think this might allow doing more things with the disc drive on all(?) ps2 models like running copied/homebrew ps1 discs (currently requires a modchip afaik), or potentially developing replacement optical drives/hardware emulators

PS2 emulation leaves a lot to be desired in terms of accuracy and authenticity, and current original hardware backup solutions are not ideal or extremely cumbersome, including caveats like relying on homebrew software which alters the memory layout of games as they run, leading to inaccuracies and broken games, and needing to have multiple copies of backup loading software on your console, as some loaders will work with some games, but not with others. It's a right mess. Some solutions, such as MechaPwn, are more transparent, allowing you to burn so-called "master discs" of your game backups to DVD-R. As far as I can tell, compatibility is 100%, but if I recall correctly, this only works on specific models of console, and the process of burning a master disc can be unintuitive and relies on specific, deprecated, commercial DVD burning software.

From what I can tell, this opens the door to things like optical drive emulators, which replace the disc laser with an SD card slot, allowing the console to read game disc images no differently than the console would read a retail game.