Yes, Orbix 6 supports both classic and standard I/O streams on HP-UX.

When using the classic I/O stream libraries (not using -AA compiler flag) follow theses instructions from the Orbix 6 Migration Guide:

"The classic I/O stream libraries and header files are included in a cios subdirectory of the Orbix lib and include directories. Hence, to use classic
I/O streams in an Orbix application you should do the following:
1. Modify your source code to include Orbix header files from the OrbixInstallDir/asp/6.3/include/cios include directory.
2. Modify your makefiles to link with Orbix libraries from the OrbixInstallDir/asp/6.3/lib/cios library directory.
3. Omit the -AA flag from the list of C compiler flags. For example, to compile the Orbix demonstrations with classic I/O streams, you would have to change the cxx_demo.mk file in the OrbixInstallDir/asp/6.3/demos directory to be a link to the demo_acca0331cios_32.mk file. This is the same mechanism used to pick up the 64-bit versions rather than the default 32-bit versions of libraries on Solaris and HP."