Some small Update:
- Changed the screens to some used 15.6 '' Notebook screens => not so heavy

- rs232 for the Matrix Controller works now with some esp8266 (wemos D1) => you can switch between 3  Modes: 

   1. every screen shows fullscreen  

   2. every screen shows 1/4 of the screen (4 player split)

   3. screen 1 and 2 show half (top-botton)  of the screen, 3 and 4 fullscreen (2 Player horizontal split)

- one prototype controller is done

- updated design (with some Ikea furniture) to make the build easy an portable

More Updates will come when the 4 Controllers are done and i need to install a hdmi mod to my N64, because the Signal is to Blurry (N64=>AV2HDMI=>Matrix Controller(input and output 1080p)=>old Notebook screen 1366x768) => the av or s-video output from the n64 is to blurry to come up with all this scaling...