Stackable computer system
FIG. 1 is a front elevational view of a stackable computer system showing my new design with broken lines shown for illustrative purposes only and forming no part of the claimed design; 
     FIG. 2 is an enlarged top plan view thereof; 
     FIG. 3 is a right side elevational view thereof; 
     FIG. 4 is a left side elevational view thereof; 
     FIG. 5 is a back elevational view thereof; 
     FIG. 6 is an enlarged bottom plan view thereof; and, 
     FIG. 7 is a perspective view thereof.