Vortex lattice analysis and design: VLMpc-John Lamar s two surface vortex lattice program, developed at NASA Langley. The program treats two lifting surfaces using up to 200 panels. Vortex flows are estimated using the leading edge suction analogy. This program was typed in　the NASA TN D, which contained the listing, by students in Applied Computational Aerodynamics nearly 10 years ago. John Lamar didn t have a copy of the code anymore. It has been modified to run in WATFOR, and to produce 80 column output. Now it runs in Compaq Visual Fortran. In November 2002 an executable has been added. The source now includes PC directory code specific to PCs.