The ornamental design for dual hinge portable computer, as shown and described.
FIG. 1 is a back perspective view of a dual hinge portable computer in a closed position;
FIG. 2 is a back perspective view of the dual hinge portable computer in a partially open position;
FIG. 3 is a back perspective view of the dual hinge portable computer in an open position;
FIG. 4 is a left side elevational view of the dual hinge portable computer in an open position; and,
FIG. 5 is a back elevational view of the dual hinge portable computer in an open position; and,
FIG. 6 is a bottom elevational view of the dual hinge portable computer.
The components depicted in broken lines shown in the drawings illustrate portions of the dual hinge portable computer, and form no part of the claimed design. A right side elevational view is omitted as duplicative of the views presented.