The origin of SCSI [WAS:RE: The origin of the phrases ATA and IDE ]

Tom Gardner t.gardner at
Thu Oct 5 13:18:18 CDT 2017

I suspect this might start another discussion, but as I understand it Apple had little to do with the evolution of SASI into SCSI.
Shugart Associates published SASI in 1981 and took it to ANSI in 1982 where they renamed it SCSI to avoid using a vendors name.  

To quote from the draft SCSI 1 standard

" A commercial small system
parallel bus, the Shugart Associates System Interface (SASI), generally met
the small system requirements for a device-independent peripheral or system
bus and had enjoyed significant market success. It was offered to X3T9.2 as
the basis for a standard. X3T9.2 chose the name Small Computer System
Interface (SCSI) for that standard and began work at its April 1982 meeting.

The present SCSI dpANS is a formalization and extension of the SASI. Many
existing SASI devices are SCSI compatible.

Since April 1982, X3T9.2 has held plenary sessions, at two month intervals,
plus numerous informal working meetings. The original SASI has been extended
in a number of ways"

I was at Shugart at that time and to the best of my recollection Apple was not a driver of the ANSI activity.
The Macintosh shipped in January 1984 well after the ANSI SCSI work started and its major distinguishing feature was the non-standard connector


-----Original Message-----
From: Chuck Guzis [mailto:cclist at] 
Sent: Wednesday, October 04, 2017 1:46 PM
To: Fred Cisin via cctalk
Subject: Re: The origin of the phrases ATA and IDE [WAS:RE: formatting MFM drives on a IBM PC]


As an aside, I picked up a 1986 Wren II full-height manual that
discussed the drive and its various interfaces.   Sadly, IDE isn't one,
but SCSI is referred to as "SASI Subset"; i.e. "SCSI (SASI subset)"

That concurs with my observation that SCSI was initially an Apple convention.  I can recall conversations about SASI vs. Apple SCSI.


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