Matthew Beaman of the SAM Coupé Users Group on Facebook has been developing RGB2HDMI into an interface for the SAM, with some very promising results...
www.northdevonretroarchive.co.uk
It's been mentioned that one of the people from the RGB2HDMI project was able to build a profile for the SAM by using the emulator, SimCoupe.
The SAM interface will require the additional purchase of a Raspberry Pi Zero, but Matthew is planning to release all his project files (hopefully including the model for a 3D printed case) so anyone can build their own once he's ironed out all the bugs.
Sam Coupe HDMI Interface – North Devon Retro Computing Archive

It's been mentioned that one of the people from the RGB2HDMI project was able to build a profile for the SAM by using the emulator, SimCoupe.
The SAM interface will require the additional purchase of a Raspberry Pi Zero, but Matthew is planning to release all his project files (hopefully including the model for a 3D printed case) so anyone can build their own once he's ironed out all the bugs.