IBM 601 Calculating Punch for calculating and punching punched cards, introduced in 1931. "It read two factors up to eight decimal digits in length from a card and punched their product onto a blank field of the same card. It could subtract and add as well as multiply. It had no printing capacity, so was generally used as an offline assistant for a tabulator or accounting machine . The 601 that was delivered to Eckert's lab in 1933 was a special model "capable of doing direct interpolation, a very unusual feature, especially designed for Eckert by one of IBM's top engineers at Endicott [NY]" . Eckert went a step further by connecting the 601 to a Type 285 Tabulator and a Type 016 Duplicating Punch through a calculation control switch of his own design, forming the first machine to perform complex scientific computations automatically."