  A condensed history and theoretical development of lattice-gas automata in
the Boltzmann limit is presented. This is provided as background to set up the
context for understanding the implementation of the lattice-gas method on two
parallel supercomputers: the MIT cellular automata machine CAM-8 and the
Connection Machine CM-5. The macroscopic limit of two-dimensional fluids is
tested by simulating the Rayleigh-B\'enard convective instability,
Kelvin-Helmholtz shear instability, and the Von Karman vortex shedding
instability. Performance of the two machines in terms of both site update rate
and maximum problem size are comparable. The CAM-8, being a low-cost desktop
machine, demonstrates the potential of special-purpose digital hardware.
