Seagate Ultra 320 - Manual (Page 15)

Parallel SCSI Interface Product Manual, Rev. A 1
1.0 Interface requirements
1.1 How to use this interface manual
This manual provides a description of the SCSI1 interface protocol and some general timing information as
implemented by Seagate products. The features described in this manual are typically referred to as “Ultra160
SCSI” or “Ultra320 SCSI” features. Individual drive’s Product Manual, for the various SCSI interface products,
contains additional and more detailed information on protocol, features supported, timing, and electrical/
mechanical aspects of how the SCSI interface is implemented by that product.
This manual provides a general, tutorial-type description of the ANSI SCSI (formerly called SCSI-3) system. It
is not intended to give all of the kinds of details needed to design/implement a SCSI system or product. For
information about SCSI interface details not included herein, refer to the standards listed in Section 1.1.1.
Note. The individual drive’s Product Manual, has tables that specify which SCSI features the drive imple-
ments, what the default parameters are for the various features they implement, which parameters are
changeable, and which are not.
The combination of this specification together with the details in the individual drive’s Product Manual, provides
a description of how a particular product implements the SCSI I/O system. This specification is Volume 2 of a
set of manuals that is made up of an individual drive’s Product Manual, and this manual. The older Ultra2 SCSI
Interface Manual, part number 77738479, applies to Seagate products that implement older versions of the
SCSI interface (SCSI-1/SCSI-2). This new Parallel SCSI Interface Manual, part number 100293069, is refer-
enced by newer individual drive’s Product Manuals, representing Seagate products that support Ultra160 or
Ultra320 SCSI features and other new features, such as packetized information transfer (SPI information
units), data group transfers, paced transfers, increased CRC protection, etc.
1Unless required for clarity, “SCSI” is now used instead of “SCSI-3.”