  We show that the deformations of Virasoro and super Virasoro algebra,
constructed earlier on an abstract mathematical background, emerge after Wick
rotation, within an exact treatment of discrete-time free field models on a
circle. The deformation parameter is $e^\lambda$, where $\lambda=\tau/\rho$ is
the ratio of the discrete-time scale $\tau$ and the radius $\rho$ of the
compact space.
