I use YAM display[1] with a 2012 macbook and an ipad mini from 2015, which works great! I don't think you can use another mac as a second screen though. [1]:

I use YAM display[1] with a 2012 macbook and an ipad mini from 2015, which works great! I don't think you can use another mac as a second screen though. [1]: https://www.yamdisplay.com/ https://www.yamdisplay.com/