About a year ago I knocked up an experimental configuration for the DOS-based SIBO "emulator" that allows a Gemini to think it's a Series 3a. I don't know if anyone has tried it on a Cosmo but you're welcome to give it a shot.
It has a few quirks, most notably around keyboard mapping, but it does work. Because the "emulator" is a 386-based development environment rather than a true ARM emulator it does mean that a lot of third-party apps won't run if they use C or assembler calls, but those that are pure OPAs work fine as do all of the built-in applications. Sharing files or data between the emulated Psion and other machines, even the host Gemini, is tricky because all you can really do is use the Android file system to drill down into the Psion's virtual drives and move stuff around. But if all you want is stand-alone spreadsheets this might work well.
To make the most of it you'll need to invest in a registered copy of
Magic DosBox for Android, which was £3.20ish the last time I checked. It will work with the free version, but setting it up is much much easier with the full version.
The setup files are at
https://gemini.kevreilly.uk/S3aGemini.zip and a copy of the documentation is at
https://gemini.kevreilly.uk/emulator.txtOne of the discussion threads on the Facebook Gemini/Cosmo group is at
https://www.facebook.com/groups/17746201995...05576219743418/You may noticed that there's also a Series 5 "emulator" on that web page but it is
very experimental and unsupported so I'd steer clear of it unless you're morbidly curious. It's slow as molasses and requires you to obtain and set up a working Windows 95 environment under
Magic DosBox. In all honesty it's not worth the effort. It looks cool for about five minutes but it's really just a novelty.
The Series 3a environment on the other hand is quite usable. I still play
Fairway on it from time to time. Certainly for running the Sheet application it should be great. The default installation runs at 640 x 264 pixels, so you even get more screen estate for your spreadsheets than on the original hardware.
If anyone decides to have a play, let me know how this works on the Cosmo. I've only ever seen it running on Gemini hardware.