Niek van Suchtelen writes in the AppleSqueezer GS blog:

240MB RAM disk + SD card slot
Updated: 1 day ago
As you probably know already, the AppleSqueezer GS allows you to use 13MB of
RAM in GS/OS. This is really nice (and more than is possible with any memory
upgrade), but from the beginning the AppleSqueezer contained 256MB of RAM
ready to be used. So recently, I teamed up with Antoine Vignau to unlock the
remaining 240MB that wasn't already used before. The result is a huge RAM
disk of up to 240MB, which can be used by installing a driver. You also need
to install core v7, which will be released soon! This core also allows IIGS
programmers to access the 240MB of RAM for anything else (although it's not
available as normal RAM inside GS/OS because the memory management of the OS
would have to be rewritten).

SD-card slot

While working on the RAM disk feature, we also came up with another idea:
what if you could store the RAM disk to an SD card, and load it back again
from there? Possibly even boot from it? That would almost negate the need
for external storage. And because it's loaded in RAM, access times are very
fast. It will take some time to develop this idea further, but I decided to
already add an SD-card slot to the new AppleSqueezers, so you don't get left
behind if you order one today (Although, you can still order them without
one for slightly less money.) This way, if and when this new feature becomes
available, you can update your core and have SD card functionality. Note
that this feature has not been tested yet, so it's theoretically possible
that there's an unforeseen hardware issue with the SD card slot that would
prevent it from ever working, but hopefully that's not the case. Just keep
that in mind when buying.

Availability

I received quite a few questions about when the new boards will be
available. This should happen in the next few days. After some delays from
the factory, I finally got the new boards so I'm happy to turn them into
working AppleSqueezers.

Core 7 for testing!

The latest core 7, which includes the ability to access the 240MB of RAM on
the AppleSqueezer, is now available for testing! If you're courageous, feel
free to test it and let me know if everything works well, and soon I'll move
it to the official download page!

https://www.applesqueezer.com/blog

Barana wrote:
>
> " This core(7) also allows IIGS
> programmers to access the 240MB of RAM for anything else"
> Does this mean if someone wrote a p16 program with its own memory
> management, it could access 253mb of banked execution ram?

Yes.