  We present a computational model for Szilard's engine and the information
discarding process. Taking advantage of a fact that the one is essentially the
reversed cycle of the other, we can discuss the both by employing the same
model. Through numerical simulations we calculate the work extracted by the
engine and the heat generation in the information discarding process. It is
found that these quantities depend on some realistic ingredients, which means
that the work done by the engine is no longer canceled by the heat generation
in the information erasure.
