Large Jpg wont print on printer?

My youth group is putting on a play and i made a large poster in photoshop. My father has a printer that will print up to 36" tall. At his work, there is an Auto CAD computer with tons of memory. The dimensions of the poster are 36x28 (tall x wide). On the CAD computer its saying there isnt enough memory to print. The poster is 8mb. Any suggestions on how to get this to work?