TRACKER is a Debug/MicroSabio product for AMOS which keeps track of all output sent to the screen. In doing so, it manages to implement the -1,148 (save screen area) and -1,149 (restore screen area) TCRT calls for those terminal types that do not perform these functions in firmware. Tracking is enabled and disabled with the WSET command.

A-Shell includes a functional equivalent of TRACKER that is permanently enabled, and so the -1,148 and -1,149 TCRT codes are always available for terminals on an A-Shell system. The WSET command is included mainly for compatibility and to prevent A-Shell rejecting it as an illegal command, though some of the operational switches are implemented. It always responds as the AMOS version does when tracking is already enabled:

%TRACKER flag already set

Allocated TRACKER buffer located - TRACKER 2.0C already installed

The TRACKER /?, /M, and /N operational switches have been implemented.