20x7 R/G Dot Matrix

Four Dot Matrix displays with Red/Green dots connected together. Data is sent for example from Commodore 64 (C64) and stored in shift registers which drive LEDs, meanwhile next line is loaded. This design should be able to connect three boards together and fill at once with six data lines, and two clock lines. Therefore 8bit Commodore 64 is enough to handle it. This is first version, REV 1.0, my first PCB ever. In project cover picture you can see two boards connected together. My personal record was 200Hz update rate from almost 1Mhz CPU of the Commodore 64