sim6809 was developped under Linux, and you should have no problem to compile
it on any Linux box.

sim6809 should also compile on other Unix machines, but this is not tested. If
have made modifications to make it compile on other platforms, please send me
the patches.

Before compiling sim6809, you must complete config.h. Data types are set for
an Intel x86 Linux platform.

Then, type make, and the program should compile.
To install it on your system, simply copy the file sim6809 in /usr/local/bin 
for example.