It's only the current drives in Compaq (HP!) servers which are LVD (Low-Voltage Differential) - this is a standard which was introduced with the Ultra2SCSI (which is NOT the same as UltraSCSI2!!) but has been superceded by Ultra3 and now Ultra320. All the older pluggable drives (beige carriers) are single-ended SCSI. LVD drives should quite happily operate on a single-ended chain as they will all sync down to the lowest common denominator as far as bus speed is concerned - I run several drives in this configuration.
There was also a high-voltage differential standard as well, but this only tended to be used for large external tape silos.
Compaq have never manufactured their own drives. They participated in the development of the SCSI protocols, but they always sourced units from a third party, re-branded them and blew new firmware onto them to handle the systems management gubbins, but if you're not using that you won't notice it's there (unless you have a particularly buggy version of firmware!!)
If you've got a part number for the drive I could try and cross-reference it and find out exactly what it is.
- Andy
