I replicated the circuit easy enough, compiled and uploaded my code without issues. No errors were displayed, but the simulator didn't show any activity on the MAX7219's. I double checked everything, wiring, code, etc. Most of the code appears at the start/top of the file, but the actual scrolling routines are at the bottom, the last few lines. The thing that really stuck out to me was the code color went from black to red. I couldn't find anything, anywhere, as to what caused the color change. This change to red, happened in line 281, of 1166. If any one knows why, I'd appreciate your reply.