This was the 4th version of the Pascal-P compiler created by Niklaus Wirth's group at ETH Zurich, termed Pascal-P4.

Pascal-P4 is a "Running history project". That is to say, it is a historical record, but still runs on modern computers.

Several other adaptions of Pascal-P4 exist, for example for FPC. You will have to search for the details of that, I was unable to find in in sourceforge.

All of the development and bug fixes for Pascal-P4 went into the Pascal-P5 project,

Pascal-P4 is a subset of full Pascal. It may be appropriate for bootstrapping projects, or class projects.

Enjoy.

You can find all of the Pascal-P versions here in sourceforge:

https://sourceforge.net/projects/pascal-s/
https://sourceforge.net/projects/pascal-p2/
https://sourceforge.net/projects/pascalp4/
https://sourceforge.net/projects/pascalp5/
https://sourceforge.net/projects/pascal-p6/