SWMM Users,

Since XP-SWMM has been a topic for the last few days, I thought I'd discuss X[-SWMM and FORTRAN compilers.

1. The dos version of xp-swmm used powerstation version 1.00. The interface files from this version are real*4 and binary. They are the same format as epa swmm except for 16 character alphanumerics.

2. The windows version of xp-swmm used powerstation version 4.00 and now uses Digital Visual 5.0. The interface files from this version are real*8 and binary. They are the same format as epa swmm except for 16 character alphanumerics. A user who uses an interface file from the dos version will not have a successful simulation in the windows version of xp-swmm32.

3. Digital Visual 5.0 is a powerful compiler that makes .exe programs and ..dll programs. In xp-swmm32 you have the choice of using the swmm95r.exe or swmeng.dll. We have made all the variables of swmm double precision in this version. We found that the continuity error is reduced using double precision. For example, if the error was 1 percent in the dos version it will be near 0.1 percent in the windows version.

4. Digital Visual 5.0 will make code that will work the same on an ALPHA chip as on an INTEL chip. It is also FORTRAN '90 capable.

5. I have compiled epa swmm version 4.4 in Digital Visual 5.0 without any problems except for the usual time, date, and command line changes. In version Digital Visual 5.0 you can make all the variables double precision as an interface choice. I would be willing to email anyone who needs it a copy of the double precision engine for epa swmm.

Regards,
Bob Dickinson
XP SOFTWARE INC.