[en] Two stability concepts are of interest for partial difference equations--one arises in theory--the other in practice. The theoretical kind, referred to here as asymptotic stability, is essentially just asymptotic (as Δt, Δx → 0) boundedness of the discrete solution. The other kind, referred to here as computational stability, is stability for a fixed Δt and Δx--computational instability is indicated in practice by oscillatory behavior of the discrete approximation--in particular, oscillations of period 2Δx. This report is concerned with computational stability. Only approximate stability analyses of the von Neumann-Richtmyer scheme have been done for the case of the ideal gas law. Herein a more rigorous computational stability analysis is sought. The analysis leads to a recommendation for the improvement of the time step restriction in WONDY for the case of the ideal gas law