Get an old F77 program running

[brianreinhold]

In the end the goal will be to port this old F77 program to f90+ using the Intel compiler. However the program is complex; it is an N-level quasi-geostrophic channel model used in meteorological research. It was written between 1980-1997 to run on DOS PCs. Starting 16-bit and then used DOS32a with Watcom as PCs became 32-bit. The entire GUI interface was written in assembly and wrote directly to video memory (speed). I still have some old Gateways running windows XP that can run the executable.

My goal is to hopefully install the Watcom/DOS32a compiler and IDE to be able to rebuild the program (source code and projects exist) and then step through it line by line to see how it works. If I can do this, it may help in the port. It's been 27 years since I worked with that model and there are too many details that are fuzzy. My current port is going numerically unstable. Some silly detail is missing.

At the time I had the commercial version of the compiler and IDE. Is the compiler/IDE provided here compatible with the original commercial version or am I going to run into some major issues?

Thanks.

[jmalak]

I don't know what version of the old WATCOM compiler you were using, please specify.
The IDE has been significantly changed, but it should be able to use old versions of IDE projects.
The old IDE configuration should be automatically converted to the latest one.
Note that Open Watcom is mostly backwards compatible with older WATCOM compilers, but it is improved and more restrictive, so some code changes will be required.
This does not apply to the Fortran compiler, there was no change in the language dialect, only in the runtime infrastructure (runtime libraries).
C and asm have been significantly changed, but with backward compatibility in mind. The code will require some changes, but not a rewrite.
You have to try it.

[brianreinhold]

@jmalak Thanks for your comments. Unfortunately it was so long ago I don't remember what compiler it was. I am sure I got updates. Commercial products were like that back in the 1980's. I started with 386 PCs and then 486's and I do recall when dos32a came on board which was much better. I don't recall how I handled the asm files. It may have been the IBM MASM compiler.

Though the program was quite complex, it's build structure was fairly simple. Just a bunch of FOR files and ASM files all packed into the same directory. Options like there are now were quite limited. Of course this program was for research; not for production. You wrote it do work on a certain problem and then put it aside. The best I can do, I guess, is download the exe file for x86 (my Gateway with XP) and install and try it.

[jmalak]

You can also install OW on current Windows (64-bit) and compile it there for Windows XP or another operating system, just like with old WATCOM compilers.
Try compiling and solve any problems.