I've updated spinsim with the information contained in the July 14 P2 document that Chip posted. This version of spinsim supports most of the P2 instructions that match instructions in the P1. Most of the new non-P1 P2 instructions are not supported yet, but I will implement them as more information becomes available about them.
In addition to spinsim, the attached zipfile contains a utility called qasm that converts PASM instructions to DAT LONG values. The resulting file can then be compiled by an existing P1 compiler, such as the Prop Tool or BST. The zipfile also contains a P2 version of the pfth Forth interpreter. Windows executables of spinsim and qasm are included. Executables for other platforms need to be built from the source files. Read the readme.txt files for more information.