The IBM 650 was one of IBM’s early computers and the world’s first mass-produced computer. It was announced in 1953 and almost 2000 systems were produced, the last in 1962. Support for the 650 and its component units was withdrawn in 1969. The 650 was a two-address, bi-quinary coded decimal machine (both data and addresses were decimal), with memory on a rotating magnetic drum. Although a decimal machine, limited character support was provided by the input/output units converting alphabetical and special characters to a two-digit decimal code. The 650 was marketed to scientific and engineering users as well as to users of existing IBM punched card machines who were upgrading from Calculating Punches, like the IBM 604, to computers. Because of its relatively low cost and ease of programming, the 650 was used to pioneer a wide variety of applications, from modeling submarine crew performance to teaching high school and college students computer programming.