Is it possible to run multiple copies of Wordpress

Is it possible to run multiple copies of Wordpress multisite in Mamp pro?

Backstory: over the holidays I splurged and got myself a copy of Mamp Pro.
After much research I was able to get multisite to work following the directions here.

Oddly enough when duplicate exactly what I did to get it to work for another site I get an error connecting to database.
Any advice is appreciated.