Here is the source code for the first 6 chapters of the book.
The code is all in Fortran-90 (with just a few sections in Fortran-77)
and a makefile is included to compile the whole package. The README
file in the doc folder explains how to compile the package.

Here is the Head&Humble Fortran-77 source code for the simulation
of two-beam dislocation and stacking fault images: HeadHumble.tar.gz.
(this program was modified by Patrícia Almeida Carvalho to produce
output in .pgm format, 11/05/03)

Here is the RealSpace source code for the simulation of high resolution
images: realspace.tar.gz.