Page of Laurens Schilling. Here you will find the most impressive
improvement you can do to a JX3P at the moment: A hardware and
ROM update which enables the parallel use of MIDI and the PG-200
programmer; also data transfer via MIDI now is possible. Unfortunately this upgrade is not available at the moment. It is promised for 2012 again.
http://www.kiwitechnics.com/patcheditor.htm The Painting With Sound Universal Programmer. A very cool hardware programmer for vintage synths - especially for Roland JX- and MKS-series. At the moment (2010) the programmer is less expensive (incl. shipping!) than a PG200 on ebay.
http://www.kiwitechnics.com/jx3pupgrade.htm The Painting with Sounds JX-3P Upgrade. This one will be the killer. It is a complete rewritten operating system for the JX3P including more modulation sources (additional envelopes and LFOs) and additional sequencer and arpeggiator functions.