On the PARCP Homepage you can find a documentation about building your own PARCP-Cable.
The URL is: http://joy.sophics.cz/home.htm
Itīs really easy. Just buy some normal flat cable (I can promise you errorfree transfers up to a cable lenght of 5 meters - because mine has this lenght) and two 25pin SubD plugs with these nice flat cable clamps. Exchange two pins with each other. Thatīs all.
You donīt need to solder any!