Dave,
I recommend that you call HP to determine if the instrument is 488.1 compliant. If it is, then you can use GPIB boards (even 488.2 boards), but you must use 488.1 commands (such as ibwrt and ibrd). If the instrument is not 488.1 compliant, then you cannot use it with GPIB.
I hope this helps.
Kim L.
Applications Engineer
National Instruments