I claim the ornamental design for a portable computer, as shown and described.
FIG. 1 is a front perspective view of a portable computer of the present invention;
FIG. 2 is a rear perspective view thereof;
FIG. 3 is a front view thereof;
FIG. 4 is a rear view thereof;
FIG. 5 is a bottom view thereof; and,
FIG. 6 is a cross-sectional view taken along the line 6-6 in FIG. 3 with the internal parts being omitted.
The broken lines shown in the drawings depict portions of the portable Computer. The unevenly broken lines in the drawings define the limits of the claimed design. The broken lines form no part of the claimed design.