Basic Telecommunications Access Method. The first access method common to the predecessors of VSE/ESA and z/OS: provides low-level services for reading from and writing to TP devices. Problems with the complexity of BTAM led to the evolution of TP monitors such as CICS. BTAM was largely superseded by access methods, such as VTAM, which implement the SNA procedures (BTAM does not support SNA devices). Withdrawn for VSE/ESA June 2000 and z/OS March 2000. Support ends March 2002 for both platforms.

basic telecommunications access method. A System/370-type access method that permits read or write communications with BSC remote devices.

See basic telecommunications access method (BTAM).

BTAM, or Basic Telecommunications Access Method, was a low-level programming interface specified by IBM for use on the IBM System/360.