JPLAN (a DIE product)

A free decompression simulator for the Palm inspired by DDPLAN

This is of course not intended to be used to plan dives, one would use commercial software to do that.

Current status (Version 3 released 30/Oct/2003)

New features in version 3

outstanding bugs

recent improvements and corrected bugs

Files you need to download .

Jplan.prc (The program, actually a directory with the program in it)

Mathlib.prc (A maths library, which you may already have)

I have tested it on Palm 3.5 (a m105), I think it should work on 3.1 onwards. I have used functions that require 3.1, if anyone wants to use it an earlier version I can disable those functions. If no one asks, I wont !.

You should not need to uninstall an old version first (Registration info will be remembered but profiles will be forgotten if there has been an enhancement to the file structure)

Useful info (features)

JPlan is an implementation of Erik Bakers Gradient Factor work. It can do CNS and OTU tracking.

(I have compiled his original FORTRAN program which you get here so you can compare the results to JPlan). You should also compare results to DDPLAN and GAP (to compare with gap turn alveoli water vapour on !)

I have written this for my amusement, but would appreciate if others use it (so bugs can be found faster!)


  1. Handsprings seem to have a problem with my scrolling tables, Iím looking into it Ö
  2. The code will have bugs.


Suggestions / bugs

Send to me tony.jay at (my email address, the software has nothing to with the BSAC)


I havenít written one, If you find the online (on the palm) documentation insufficient, Iíll try to improve it.

Nerdy bit

Any one with a computer can write a deco program for the Palm. All you need is the right free tools.

Useful links (DDPlanís manual covers JPlan to a great extent) (deco theory papers) GAP deco software.


  • Buhlmann/Erik Baker for publishing their work.
  • Gordon Henderson for DDPlan, CNS / OTU Look up tables and discussions
  • Victoria Bennett for diving the plans
  • Keith Sabine for suggestions and testing.
  • Kees Hofwegen and Peter Fjelstenís GAP program for verification of the altitude calculations (and comparison of schedules)
  • Jez Kent for numerous suggestions and testing.