I did not believe that Hercules and TK4- would work well on a Raspberry Pi 4.? Being a RP4 rookie, I found a website that gave easy direction to downloaded and install Hercules and TK4-.? Sure enough - it worked.? It seemed to me to be as responsive as on my desktop winblows 10 box.? My first challenge is to change the sign on panel to read "My Raspberry Pi Thinks Its a Mainframe".