IBasic or Instrument Basic is a simplified HP Basic embedded in instruments (for ex 70820A). There are 2 Basic running Under Win : HTBasic originaly developped by HP (win 95, 98, NT) and the license was sold to Transera who sells still HTBasic : costly but runs Under Win7/10 with tremendous bridges between the Microsoft world (cut, paste, Excel...).
You have fo find the original HT Basic which looks on your screen as a 9000/300 (black screen, white bar at the bottom fot the Fx functions).
Beware :no HPIB discs supported on the bus and most of the progs for 9000 will not run under HTBasic (except complex modifications and often abolutely not compatible if the original prog --most of HP test progs -- contains CSUB compiled progs).