converting NAD27 and NAD83

Has anyone ported the DOS programs NADCON(ver 2.0) and CORPSCON(ver 2.1)
  to unix for use with GRASS? They were developed by NGS for converting
  NAD27 and NAD83 coordinates back and forth (I believe).

Thanks in advance

    __ __
   / ) / / ) Research Specialist
  / / _ /_ _ /__/ Ctr for Advanced Spatial Technologies
  (__/_(_)_/ /_/ )_ / _ National Ctr for Resource Innovations
    / 12 Ozark Hall, Univ. of Arkansas
   / Fayetteville, AR 72701
John E. Parks phone: (501) 575-6159
[john@tang.uark.edu] Internet or: (501) 575-4575