John says: "I have a photo of me repairing one of two 1219 while on-board the USS Midway CV-41. They were a redundant system (configured like a Master/Slave) to land aircraft on a carrier automatically without the pilots control. We used two, in case one computer went down the other would take over. Pretty cool and oh yes many hours/days without sleep repairing an intermittent on these beasts. " Click image for larger view.