IBM integer and double formats

[john.goodleaf]

I'm poking at writing data out to a SAS XPORT file (transport file).
Each record must be 80 bytes long, ASCII. Integers should be "IBM-
style integers" and floats should be "IBM-style doubles." Now I have
some idea what that means from reading a C source file documented by
the SAS institute, but before I go over the deep end trying to write
my own routines, does anyone know of an already-done means of writing
integers and floats out to their IBM mainframe equivalents?

Thanks,
John