Finished placement of all components and beginning hand routing of traces

 PLACED ALL COMPONENTS WITH ROUTING AND ACCESS IN MIND

I organized the components around the board so that the routes would be as direct as possible. For example, the output driving circuits use 74LS06 chips with six open collector outputs. I arranged the screw terminals for those around each chip in the proper order so that the paths would not cross. I also arranged the six resistors and the transistor for each input receiver circuit where traces would be direct and not need to cross.

The larger routing work will be to take the signals from each of the receiver and driver circuits and route it to the twin 64 pin connectors that mount the FPGA board. I arranged the receiver circuits in approximately the sequence of the pins on the connector which hosted the inputs. Similary I put the seven buffer chips in the order where their inputs will come from the other 64 pin header that hosts the outputs. 

I also considered the wire routes for all more than 80 signal wires that run from the SAC cable connector to the various screw terminals. I oriented the terminals to face the path of the wiring and left room to get wires in and out for service. 

HAND ROUTING OF EASY TRACES UNDERWAY

I began to draw traces between the components of each of the 36 receiver circuits as well as the LED driver circuits and the path from the driver circuit buffer chips to the screw terminals. I will let the system route the ground, 5V, 3.3V and 3V power lines. Too, I will let the KiCAD system work out the trace routes from the twin 64 pin connectors to all the circuits. 

SNAPSHOT OF THE SCHEMATIC