Hi, I do remember that when installing HP-UX 9 and earlier, you could not mix and match SCSI and HP-IB. If you boot from HP-IB you can install on HP-IB, if you boot from SCSI, you can install on a SCSI disk. That may be a limitation in the installer. Once you have everything installed, you can use any device. I am very sure that this was the case with the 800s. I am not quite sure about the 300 series. I once owned a 380 and it worked well with SCSI disks and the onboard SCSI port. regards, Dennis