I think we are having notation problems.
In my original post I was writing in the notation of the wiki article. I was complaining that I couldn’t get the resulting function of the convolution to be drawn in real time. In the wiki article the resulting function is written in the notation (f*g)(t). Where as the product of f and g would be written as f(t)*g(t) or in this case since one of the functions is offset f(t)*g(t-t). The convolution is therefore defined as (f*g)(t) = Integral[f(t)*g(t-t), {t`, -Infinity, Infinity}].
Nevertheless, in my original code I was shading the area under the product of f(t)*g(t-t`) which gives the overlap area for two square waves of unit height and width…but not much else 
!