Each display has an array of 16x3 and 20x2 boards, each board contains an array of 10 x (4x8) RGY LED blocks

Boards are serially linked to each other in each row

Each row is connected to the board using a 10 bit ribbon

The ribbons are connected from the main board to a OCT buffer (HCT244) and a shift register

After some poking around, i found the following lines -

RCK - Shift Register RCK

Green Bit - Shift HIGH to light up Green pixel

Row ID (1-3) - a 3 bit number for the following rows - (ID 1,2,3)

SRCK - Shift Register SRCK

5v+ - positivie

Red Bit - Shift HIGH to light up Red pixel