Hello Chris et. all,
There are two versions of transputer emulator available on my website. The first is the jserver emulator which is a highly modified version of Julian Highfield's original T414 transputer emulator, supporting T414, T425 and T800 processors and multi-processor support. The second is the T414 / T425 / T800 VBC emulator which is re-written from the ground up by my very own hands, using the ucode code I extracted from the REAL transputers.
The source code for these two projects are not available for public release, only the execute code. These emulators (in particular the jserver) have been available for many years to the transputer community for free use.
If you want source code then Andras Pahia has a working version of Julian Highfield's original code supporting both T4 and T8 emulation. See
https://github.com/pahihu/t4
Regards
Gavin