High Quality Content by WIKIPEDIA articles! The IBM 728 magnetic tape drive was used on the SAGE AN/FSQ-7 computer. It was physically similar to the IBM 727, but with significantly different specifications. This is one of several IBM 7 track tape drives. On the 1711's control panel, there was a bank of seven decimal digit manual entry switches that could be read by the computer. The 1711 also contained address circuitry for the IBM 1712 Multiplexer.