V4.0 - LED Matrix lights up

I found a great deal of help with this online. Oddly specific to the task, a search for MAX7221 and Arduino gets a lot of results in Arduino forums and project pages. There's a little code, but mostly overview, basic questions answered, details meaningless to beginners (like me), and my favorite pseudocode.

I did get this to work anyway. I'll be adding screen shots, code examples, and process later. Here's some visual documentation: