The C code is a complete rewrite done by Guy Harris for 4.4BSD and is
not the original from v7 at all. Unfortunately, the data file itself,
without which the rest isn't useful, was not freed until Caldera
released all of 32v a few years ago, so it was not in 4.4lite.
The data file, the ching nroff macros, and the driver script are under
Caldera or Caldera+Berkeley copyright.
I've partially redone the driver script from 4.4 (there was no point
in using a temporary file for the hexagram), which was already
partially redone from 32v. (As an aside, it is nutty that the script
needs a copyright so many times longer than the code.)
I've renamed "cno" to "castching", "phx" to "printching", (the
traditional names were opaque), and put them in /usr/libexec/ching
instead of the v7 /usr/games/ching.d. The data file and nroff macros
are in /usr/share/games/ching