Something with the AWACS driver (need to run off an instrumented build and boot the kernel in debug mode to see what's up, just gotta get a round tuit). The 6500 is technically Unsupported but Compatible in Be's support matrix. Some people report the sound works, some people report it doesn't. Ditto for the TAM, which is basically a 6500 in a cool suit with an LCD.

mmuman was still talking about it recently, but the issue is that the compiler used under BeOS is proprietary - Metrowerks mwcc, and is basically DOA now (do they even still make is commercially available?.) The PowerPC version of BeOS uses the proprietary Apple PEF exe format too, and there are almost no modern compilers that support that format (Retro68 is the only one I know of.) Haiku is therefore likely to not support anything legacy from BeOS PowerPC, and that makes even bootstrapping difficult, as you need a whole new OS to run the new code.