SCSI-2 plus

Gerry Houlder Gerry_Houlder at
Mon Jun 13 08:43:13 PDT 1994

The term "SCSI-2 plus" is not defined or sanctioned by the X3T10 committee or
any other standards committee. The term was originally defined by Seagate
engineering, for internal use, to describe the SCSI implementation for our
newest disk drives. The term is intended to indicate that the drive
implementation is SCSI-2 compliant but includes features that are described in
proposals that have been accepted for inclusion in SCSI-3.
Apparently Seagate sales and marketing are also using the term to describe the
SCSI implementation as well. There are various marketing and legal reasons for
1) This drive isn't a "SCSI-2" drive because it contains items not described in
the SCSI-2 standard.
2) We can't call it a "SCSI-3" drive because the applicable SCSI-3 documents
haven't been published, or even forwarded to X3 to begin the publication
process. Since a SCSI-3 standard doesn't exist, a SCSI-3 device is offically
3) We have to call it something better than SCSI-2 to complete with the
companies that already claim to have "SCSI-3" drives.
The SPI (SCSI-3 Parallel Interface) and SIP (SCSI-3 Interlocked Protocol) draft
documents that are being developed in the X3T10 standards committee include the
SCSI-3 additions to connector definitions and new messges that may be supported
in a "SCSI-2 plus" device. The new mode page lengths and new commands would be
in the SBC (SCSI-3 Block Commands) document, but a draft doesn't exist yet. The
individual proposals that have been accepted by the X3T10 committee for
inclusion in SCSI-3 are still the only documentation for these features. A
bunch of such documents have been accepted over the last 2-3 years. These
documents were only distributed to committee members and meeting attendees.
Seagate provides a SCSI Interface Specification that describes the added
features. The spec also lists the Seagate products it is applicable to. ASK THE
SALESMAN/MARKETEER TO GIVE YOU A COPY. This may leave you wondering whether our
implementation is the same as the SCSI-3 proposal, but all proposals are
subject to change until final publication anyway. Even if we did it exactly
like the proposal says, the final SCSI-3 document might be different.
Gerry Houlder -- Gerry_Houlder at
Seagate Technology   -   920 Disc Drive   -   Scotts Valley, CA 95066 USA
Main Phone 408-438-6550   -   Email Problems postmaster at
Technical Support: BBS 408-438-8771  Fax 408-438-8137  Voice 408-438-8222  

### OGATE Version 8 message trace and attachment information:
### MsgFileName: m:\mgate\outbound\794.MSG
### Org Date:    06-13-94 08:31:26 AM
### From:        Gerry Houlder at SEAGATE
### To:          scsi @ WichitaKS.NCR.COM @ internet
### Subject:     Re: SCSI-2 plus
### Attachments: none

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