 IBM, which dominated the data processing industry through most of the 20th century, introduced its first commercial transistorized computers beginning in 1958, with the IBM 7070, a ten-digit-word decimal machine.It was followed in 1959 by the IBM 7090, a 36-bit scientific machine, the highly popular IBM 1401 designed to replace punched card tabulating machines, and the desk-sized 1620, a variable length decimal machine.IBM's 7000 and 1400 series included many variants on these designs, with different data formats, instruction sets and even different character encodings, but all were built using the same series of electronics modules, the IBM Standard Modular System (SMS).