FIG. 1 is a rear isometric view of a base for a computer input device showing our new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a left side elevational view thereof;

FIG. 4 is a rear elevational view thereof;

FIG. 5 is a front isometric view thereof;

FIG. 6 is a bottom plan view thereof;

FIG. 7 is a right side elevational view thereof; and,

FIG. 8 is a front elevational view thereof.

The broken lines are for illustrative purposes only and form no part of the claimed design.