I had a request to provide a software systems diagram of our current mortgage software system set-up and provide another one with the new loan origination system inserted and then a final one for our core system inserted.  Any example diagrams out there?

 We have a diagram in RML that we now call the ecosystem map. Previously we called it a system context diagram. Here are a couple of posts on the topic

http://requirements.seilevel.com/blog/2011/05/part-six-requirements-visualization-training-a-guide-to-rml.html

http://www.seilevel.com/wp-content/uploads/RML_Quick_Reference_REV.pdf