From the interpretive text: "This function table, on of three originally used with ENIAC, stored numerical constants. It is the equivalent of "programmable read-only memory" (PROM) in modern computers. ENIAC solved mathematical equations. Constant values in the equations were set by turning the switches on the front and back of the function tables; variable values were entered using punch cards. Each function table could hold 208 six-digit numbers or 104 twelve-digit numbers.