  The QCDSP computer (Quantum Chromodynamics on Digital Signal Processors) is
an inexpensive, massively parallel computer intended primarily for simulations
in lattice gauge theory. Currently, two large QCDSP machines are in full-time
use: an 8,192 processor, 0.4 Teraflops machine at Columbia University and an
12,288 processor, 0.6 Teraflops machine at the RIKEN-BNL Research Center at
Brookhaven National Laboratory. We describe the design process, architecture,
software and current physics projects of these computers.
