The stable wrench-feasible workspace (SWFW) of a cable-driven tensegrity manipulator defines the set of all end-effector poses reachable with a stable equilibrium configuration, for a positive and bounded input cable forces. A method for determining the boundary points of the SWFW of a manipulator with two anti-parallelogram (X) joints and link offsets, actuated remotely by four cables, has been proposed. It involves two 1-dimensional (D) scanning of the joint space to firstly determine the bounding points of the stable wrench-feasible joint space (SWFJ), followed by those of the SWFW. At each grid in the joint space, a set of univariate polynomial equations are solved to determine the desired boundary points with a good accuracy. The steps involved in the derivation of two of these polynomials are detailed, while the others are also derived in a similar manner. Finally, a numerical example of the 2-X manipulator is considered and its SWFW boundary points are visualized.