<<Does anyone know the make/brand/manufacturer of the disk drive inside an HP A3353A opt 0D1 ... a internal 4GB Fast-Wide Differential half height SCSI-2 disk drive? (HP List price $2300)>> They aren't differential devices; as nearly as I can tell, HP doesn't "do" differential SCSI, of any kind, on any of their platforms. WRT the 4GB drives: Ours are Seagate ST15150Ws, which is consistent with the info on the A3353A shown at http://hpcc997.external.hp.com:80/csy/docs/ex3b50/product.html which is supposed to be the same as in Chapter 8 of the Express 3 "Communicator". Steve Dirickson WestWin Consulting (360) 598-6111 [log in to unmask]