A-Tech 8GB RAM for Apple MacBook Pro (Mid 2012), iMac (Late 2012, Early/Late 2013, Late 2014, Mid 2015), Mac Mini (Late 2012) | DDR3 1600MHz PC3-12800 SODIMM 204-Pin Memory Upgrade at Amazon.com
New Apple iMac (2012) 21.5": Unboxing & Demo - YouTube
Bringing new life into this free late 2012 iMac is going great so far now that I know I can at least install Big Sur on it. SSD and a proper keyboard