Hi Richard,
If you extract the story.dat from the "echoes_speccy.dsk" disk image and change its file type to z3 or z5 (honestly, I do not know the differene) and select it from the file browser, then the ZX Spectrum's Next built in infocom interpreter will run it and it appears to work fine! (Just tried it out very briefly)
I made it work with the Next's built in CP/M too, but this isway more convenient! :-)
Hope This help you!
You are welcome! Yes, you are right, if those games use the same mechanism. You probably know about the Magnetic Scrolls and Level 9 collections made for the spectrum next, very fine old text adventures, all of them. These can be downloaded free of charge and also there are several more new ones (beside the excellent Echoes of the Futures) available for purchase here in itch.io!
It's funny you should mention those compilations, because… not only am I familiar with them, but in fact I was the person who designed the packaging for the Level 9 Compilation! (Check the small-text credits on the back of the box – I got a nice commendation from Mike Austin for producing something that looked so authentic to the Level 9 style!) However, those adventures don't use Inform files; both sets use their own proprietary formats, and Stefan Bylund produced very nice Spectrum Next versions of the interpreters needed to run them. You're right that some of those games are indeed also available for the Spectrum +3 (either exclusively or with pictures exclusive to the +3), but they still use a special interpreter and aren't available as Inform files.
In my previous comment, I was thinking primarily of those few adventures for the Spectrum +3 that are ONLY available on the +3 (not other Spectrum models) on CP/M disks, and which could presumably be extracted from those disks and run 'natively' on some other Inform interpreter, such as ZXZVM on the Spectrum Next. Presumably the same would also be true of adventures packaged up as Ozmoo disks for other platforms, though I haven't investigating extracting those yet either. I don't suppose there are lots of adventures like this, because Inform-format adventures are mostly released as separate Inform files and don't need to be extracted from a platform-specific disk… but there may well be a few like that, so it's worth bearing in mind.
