This package contains programs to plot SEGY seismic data files using the GMT mapping transformations and postscript library. pssegy generates a 2-D plot (x:location and y:time/depth) while pssegyz generates a 3-D plot (x and y: location coordinates, z: time/depth). Locations may be read from predefined or arbitrary portions of each trace header. The package is maintained by Tim HenstockA.8.