Determine HPIB address programatically

[dramsey]

I have an HP – 87 connected to a 9127A flexible disk drive.

The computer's HPIB address is set to the default, seven. The drive is set to four-- easy to see since setting the drive address requires that you turn a little numbered dial.

When I turn the computer on, it automatically sees the drive and sets of is the default mass storage device. I can catalog the disc, load and run programs, and do anything I need to.

As I understand it, typing:

mass storage is ":D740"

...should not change the behavior of the system, since the computer is HPIB device number seven in the drive is HPIB device number four.

However, once I use this mass storage statement, I can no longer access the disk. The attempt to gets an "error 131: timeout".

Does anyone have any idea what's going on here? I'm trying to get the syntax of the statement down so I can test an HPIB hard disk drive I acquired.