Special-purpose computer for holography HORN-3 with PLD technology. We have designed and built a special-purpose computer for holograph, HORN-3 (HOlographic ReconstructioN) using PLD (Programmable Logic Device) technology. We could integrate a pipeline to calculate hologram into one PLD chip, so that we can readily parallelize the system. By mounting two of the PLD chips on a PCI (Peripheral Component Interconnect) universal board, HORN-3 calculates light intensity at high speed of about 1.2 G flops. The cost of HORN-3 board is 200,000 Japanese yen (1600 US dollar). We obtained (1024 imes 768) grids hologram from a virtual 3D-image composed of 2500 points in about 60 sec with the HORN-3 system.