Parallel SCSI, Marketing Group Names

Gene Milligan Gene_Milligan at
Wed Nov 22 10:41:39 PST 1995

The proposal below may have some good elements but it will add to the 
confusion. Fast 20 is not a comprehensive SPI definition. It is an adjunct to 
SPI. Consequently the proposed naming would need to distinguish between the 
documentation and the capability.

To: scsi @ (SCSI Reflector) @ Internet
cc:  (bcc: Gene Milligan)
From: gerry @ (Gerry Johnsen) @ Internet @ WORLDCOM @ SEAGATE 
Date: 11/22/95 09:03:09 AM
Subject: Parallel SCSI, Marketing Group Names

A Proposal for naming parallel SCSI

SPI %%X##-**
        %% = 5 for slow
        %% = 10 for fast
        %% = 20 for fast-20
        %% = 40 for fast-40

        X## = X1 for 8 bits wide
        X## = X2 for 16 bits wide
        X## = X4 for 32 bits wide

        -** = -SE for single ended
        -** = -DF for differential
        -** = -LV for Low voltage differential

For Example:

  SPI 5X1-SE  Is slow SCSI Single ended
  SPI 10X1-SE Is fast SCSI Single ended
  SPI 20X2-DF Is fast-20 wide SCSI differential

Admittedly its not too sexy but it does the job of defining the 
different variations while allowing the user to quickly compute the 
maximum bandwidth - 20X2 = 40 MB/s.  It also separates parallel SCSI 
|from the serial variations and allows future expansion for speed, 
width and signal types.

For the SCSI Parallel Marketing Group I suggest

  SPA - SCSI Parallel Association

Gerry Johnsen                           Ciprico Inc
voice (612)551-4000                     The Disk Array Company
fax (612)551-4002                       2800 Campus Drive
gerry at                       Plymouth, MN 55441


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