Hi,
I am currently in e-mail contact with an HP-86 fan who is writing a HP-86 emulator. He said he has based this on an HP-71/HP-75/Capricorn emulator.
He has also produced a disassembler.
One area he is stuck on is input / output, this is very poorly described in the Assembler ROM manuals. I have heard there was a manual called something like 'Input / Output Assembler' that may help, but I have yet to see a copy.
If anyone else has an HP-85/86/87 emulator on the way it might be worth pooling ideas.
Regards,
John