ESDI cabling is definitely the ST506/412 interface used on old MFM (e.g. Seagate ST-225) or RLL (e.g. Seagate ST-238). If the 34-pin control cable is straight through (without the twist) select drive 0 if the selection is 0 and 1. If the selection is drive 1 and 2, select drive 1 (nomenclature varies among manufacturers). Ensure the terminating resistors are installed or you are asking for trouble. If the 34-pin control cable has a twist and you have only one drive attached to the end of the cable with the twist, use drive select 1 if your drive nomenclature is 0 and 1. If the drive select nomenclature is 1 and 2, select drive 2 and make certain you have the terminating resistors installed. Two drive scenario: 34-pin control cable with twist, drive at end of cable with twist use drive select 1 if drive has 0 and 1 as drive selects or 2 if using 1 and 2 drive selects and again ensure the terminating resistors are installed in this drive. The drive in the middle of chain should use drive select 1 if drive has 0 and 1 as drive selects or 2 if using 1 and 2 drive selects (yes, use the same drive select as the C: drive attached to the end of the cable) and make certain the terminating resistors are removed from this drive which will be seen as D: drive. If the 34-pin cable has no twist, C: drive is set for 0 (if drive selects are 0 and 1) or 1 (if drive selects are 1 and 2) and connected at the end of the cable with the terminating resistors installed; D: drive is set for 1 (if using drive selects 0 and 1) or 2 (if using drive select 1 and 2), connected in the middle of the chain and must have the terminating resistors removed. Marty