 <p>You want to get an ISO 7185 compliant compiler to compile that. It is true that Pascal-P4 (the proper name) was written prior to the ISO 7185 standard. However, the adaption to the standard is generally less of a change set than adaption to a dielect.</p> <p>You will find that work already done and documented at:</p> <p><a href="http://sourceforge.net/projects/pascalp4/" rel="nofollow">http://sourceforge.net/projects/pascalp4/</a></p> <p>It specifies use of GPC. However, as Marco said, it is possible with more work to adapt to FPC, and I believe the FPC folks are improving the ISO 7185 capability of their compiler.</p> <p>Having said that, I'm not sure why Pascal-P4 would be an interesting target. Pascal-P4 was a subset compiler, meaning an incomplete implementation of Pascal. You will find a complete implementation as Pascal-P5:</p> <p><a href="http://sourceforge.net/projects/pascalp5/" rel="nofollow">http://sourceforge.net/projects/pascalp5/</a></p> <p>And I believe it has less portability issues as well.</p> <p>Good luck.</p>