SCSI SE Compatability

[Jeremy_108]

I have an HP DDS3 internal backup drive with a SCSI SE interface.

Will this be compatible with most SCSI cards, as the cable from the old one it is replacing is a different size?

[A. Clay Stephenson]

It will work with SE-SCSI controllers and LVD SCSI controllers but do not connect it to an HVD (Hi Voltage Differential) controller. HVD devices are rather rare these days.

[Jeremy_108]

Thanks! Tell me, are the HVD controllers easy to indentify?

[A. Clay Stephenson]

Only by part/model number. The same cables can be used on SE SCSI and HVD SCSI so the connector is not a definitive test.

[Bostjan Kosi]

Hi,
On the backplate of all SCSI controllers there is a sign. This sign is different on HVL and LVD (SE) controllers. LVD is like a square with a small line on one corner and there is like half of the second square inside (second inside square is sometimes missing). HVD sign is again a square with a small line from one corner but there is half of another square around it. So this is the simplest way of telling what kind of SCSI controller is inside the server without opening it. HVD controllers were mainly used for Tape libraries...

BR
B.

[Jeremy_108]

Thanks people - that's a great help. So would it be fairly safe to assume that a four and a half year old DDS3 drive on a Compaq server is unlikely to be HVD?

[A. Clay Stephenson]

You've already stated that the drive was SE-SCSI. The DDS3 drive is SE-SCSI and since you originally posted this in the HP9000's forum, I can tell you that very few of those boxes had any of the SCSI symbology on their controllers. Also, DDS/DAT drives on those boxes were always SE-SCSI. You really have to know the part numbers. You concern now is the device to which you will now be attaching this drive. If it's a SE/LVD controller then you are fine.