The Picomem ISA card created by FreddyV is for all 808x computers and brings additionnal RAM (if you don't have 640 Kb), EMS memory, hard disk and disk drive images support, thanks to a Raspberry Pico (like the PicoGUS sound card). It's still work in progress. Rodrik Studio did two videos about the Picomem, one in english, the other in french :

• english video
• french video (see below)