High Quality Content by WIKIPEDIA articles! Queued Telecommunications Access Method (QTAM) is an alternative to the simpler Basic Telecommunications Access Method (BTAM) communications access method, introducing built-in queuing. It was developed by IBM as part of DOS/360 and OS/360 and used mainly to transmit batches of data. The OS/360 version of QTAM was not carried over to OS/VS1, SVS or MVS, although its successor, TCAM, was.