Debug versus CheckMate

I am porting a large program that was compiled with the Digitial FORTRAN / COMPAQ FORTRAN compiler to FTN95 with the Visual Studio Shell. The source is now compiling, linking and generating a running EXE. I have built two EXE's. Version 1 using DEBUG+WIN32, and Version 2 using CheckMate+WIN32. Both versions use the exact same source code.

Using the Visual Studio debugger to step through the program, Version 1 shows a variable equal to zero, while Version 2 identifies the same instance of the variable as UNDEFINED. I assume CheckMate is giving me a true result and the variable is undefined. So now I am trying to hunt down the error. (I did not write the original code and it is many thousands of lines long.)

QUESTIONS:

1. What are the differences between DEBUG and CheckMate compiler options? Can someone point me to the correct spot in the documentation? I don't see in the documentation which type of errors DEBUG versus CheckMate will flag.

2. I am learning the debugger in Visual Studio. Is there the option to watch a variable and break execution whenever the variable changes? Again, can someone point me to the correct spot in the documentation?

Thank you.

1. Basically DEBUG only plants code for navigating through the debugger whilst CHECK etc. add to this, code for checking for various faults at run time.

2. I am not sure what is available when using the Visual Studio plug-in but from the stand-alone debugger SDBG, you can set a 'Use' break by right clicking on the variable in the 'Variables' window.