The ornamental design for an arithmetic and controlunit, as shown and described.
FIG. 1 is a perspective view of front, top and right side of an arithmetic and control unit showing our new design;
FIG. 2 is a front view thereof;
FIG. 3 is a rear view thereof;
FIG. 4 is a left side view thereof;
FIG. 5 is a right side view thereof;
FIG. 6 is a top view thereof;
FIG. 7 is a bottom view thereof; and,
FIG. 8 is an enlarged view taken along line 8-8 and line 8′-8′ in FIG. 2.
The broken lines shown in the drawings illustrate portions of the unit, and form no part of the claimed design. The tiny dot-dash line shown on the right side of FIG. 8 represents the boundary between claimed and unclaimed areas.