Terry,
If you could get a chance to review the document below or pass it on to the appropriate party that would be great. (I believe you were the one who asked for it originally?)
I have done this work. The results can be seen at:
http://www.incunabulum.com/code/projects/freebsd/freebsd-bios-interaction.tx...
I have also rewritten boot0.s to use the BIOS COM Port Services (INT 14h):
BMS