dBaseIII had a SET RELATION TO command dBASEII had a SET LINKAGE command.
In looking through my old dBASE junk I came across a couple of add-ons from Ashton Tate vintage 1986: dBASE TOOLS FOR C (provided graphics primitives and basic Pie and Bar charts, Array creation etc) and dBASE PROGRAMMERS UTILITIES (provided for 20 files open, SOUNDEX(),SAVESCR(),lightbar menus?,DXREF,DREPAIR,DPROTECT etc.)
The latter was authored by (among others) Wayne Ratliff - what ever happend to him? Does anyone know?