Determine HPIB address programatically

[dramsey]

Well, either the HP-87 docs are wrong, or there's a fault in the DIP switch on the computer that sets the host address, because with the switches in the position the manual says should be "7", this doesn't work:

MASS STORAGE IS ":D740"

But this does:

MASS STORAGE IS ":D840"

So, mystery solved, kinda.