You will find here an emulator for the HP85B & HP86B/87 :
New release with FORTH support (only HP87 roms included) :
Windows zip archive with only binaries : Hp8x-forth.zip
(you need the previous one and overwrite any common files)
Here some informations about an HP85 recreation with an FPGA : FPGA HP85B
Here the next step, an HP86b+ with the same FPGA : FPGA HP86B
Some more emulators for android and windows here.