M2 director on T6 trailer 1932 source:Wikimedia commons
Simplified system layout and data flow diagrum for Sperry T-6 anti-aircraft gun director computer.
Mindell, D. A. (1995) ‘Anti-aircraft fire control and the development of integrated systems at Sperry, 1925-40’, IEEE Control Systems Magazine, 15(2), pp. 108–113. Available at: [link]