  The Klein-Gordon equation, the Maxwell equation, and the Dirac equation are
presented as partial difference equations in the eight-dimensional covariant
discrete phase space. These equations are also furnished as
difference-differential equations in the arena of discrete phase space and
continuous time. The scalar field and electromagnetic fields are quantized with
commutation relations. The spin-1/2 field is quantized with anti-commutation
relations. Moreover, the total momentum, energy and charge of these free
relativisitic quantized fields in the discrete phase space and continuous time
are computed exactly. The results agree completely with those computed from the
relativisitic fields defned on the space-time continuum.
