OrbWeaver is an interactive editor for 2-D spherical-shell finite-element grids,
which was written in Microsoft BASIC for the DOS operating system.
The executable version ORBWEAVE.exe can also be run under Windows.
However, the 640 KB limit on memory, resulting from the kludgy method of
memory addressing under DOS, remains in place.

For this reason, Zhen Liu and Peter Bird rewrote the program
in Compaq Visual Fortran 6.6A for Windows (32-bit versions, such as:
Windows 95, Windows 98, Windows ME, Windows NT, Windows 2000, Windows XP, Windows Vista).
The new program is called OrbWin.
It allows access to very large amounts of memory (up to 2 GB?),
with the proviso that the user has to anticipate the size of the grid(s)
that will be edited in any work session, and allocate storage at the start.
(It does no harm to allocate more storage than needed.)

We hope that future 64-bit versions of Windows will support 32-bit
executables like OrbWin.exe, but this remains to be seen!

OrbWin also supports the 2 additional nodal data added in the 
2006.08.29 version of Shells:
-compositional density anomaly of the entire lithosphere;
-non-steady-state curvature of the geotherm due to transient cooling/heating.

Another generalization of function is that OrbWin now explicitly
supports the slightly-different variants of .feg file structure that
are needed for my kinematic F-E programs NeoKinema and/or Restore
(e.g., no fault elements; different nodal data fields).

Because of this increased functionality, /OrbWin/ has been placed
at the root of the /oldFTP/ directory structure,
instead of appearing here within /oldFPT/neotec/SHELLS/.

Peter Bird
UCLA
2007.10.05