AT&T MERLIN LEGEND Release 2.0 Data User's Manual page 16

About Data Communication Equipment
The following analog data stations are supported:
Analog Voice and Analog Data. This endpoint
includes an analog multiline telephone and a data
terminal or PC connected to the system via a modem.
A General Purpose Adapter (GPA) supplies the tip/ring
(T/R) interface for the modem.
1-6 Data Stations