Finshed the last bit of my console program. It worked correctly. Its not effiecent as it could be, but its reasonably clear and correct.
I've hacked it into my old code and after chasing down a bug with the screen constructor not intiliazing the transform matrixes correctly it now all seems to work :o
So i need to clean up the code one again.
Then I need to introduce movement.
I really need to look up Assert implmentation in C# too. I know they're somewhere around.