Shhhh! You trying to goad Mr. Respectful into another anecdote?
Anyway, does a ballistic cam in the M12 Gunner's Sight really count as a "ballistic computer"? I always thought that was the separate cam-operated mechanism in the M48 that linked shafts to the rangefinder and ballistic drive...the gunner switched cams to match the ammunition used, while the operation of the rangefinder entered the computer, which output a gun elevation to the periscope reticle.