Dual Monitors on RPi 400

Hello, apologies if this has been asked before. Is it possible to get dual monitors working on Risc OS? I use Raspberry Pi 400s in the classroom and it would be nice to mirror the screen onto the interactive whiteboard. At the moment, I can only get one screen to work at a time, the other once shows the colourful screen you normally get just after switching on the Pi. Thanks for any info…

@ Simon

Is it possible to get dual monitors working on Risc OS?

Yes, but only through a commercial utility at the moment:

https://sendiri.co.uk/geminus/

Hope this helps,

The Rpi 4 has two HDMI output ports. Is it possible to get them to act as a splitter, i.e. output the same data streams? Then one could be attached to the monitor, the other to a video capture device. Or does one have to buy an HDMI splitter as a separate item?