Engineering prototype of a logic module for the Block II Apollo Guidance Computer (AGC), measuring 9.75″ x 4.75″ x .5″, marked on the edge: "Logic Module A16, 124939-171, Rev. -, Mfd. by Raytheon Co., S/N Raytheon Engineering Prototype." The open sides of the module reveal a total of 120 Fairchild integrated circuit chips (two rows of 30 on each side), all marked, "FSL, 1090-1, 503." These chips each contain six transistors comprising two 3-input NOR gates. In fine condition. From the Don Eyles Apollo Computer Collection.