Path: utzoo!attcan!uunet!husc6!rutgers!ucsd!ucbvax!dewey.soe.berkeley.edu!oster
From: oster@dewey.soe.berkeley.edu (David Phillip Oster)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Apple HD SC 80 does not support Asynch i/o.
Keywords: Hall of Shame entry?
Message-ID: <27336@ucbvax.BERKELEY.EDU>
Date: 4 Jan 89 11:05:10 GMT
References: <11605@dartvax.Dartmouth.EDU> <10205@well.UUCP>
Sender: usenet@ucbvax.BERKELEY.EDU
Reply-To: oster@dewey.soe.berkeley.edu.UUCP (David Phillip Oster)
Organization: School of Education, UC-Berkeley
Lines: 10

In article <10205@well.UUCP> brecher@well.UUCP (Steve Brecher) writes:
}by the hardware, and the Macintosh supports neither for SCSI I/O.  It might
}be theoretically possible for a SCSI disk driver to perform seeks
}asynchronous to program execution, but it would have to poll for seek
}completion by using a VBL task or Time Manager task; that would probably add
}enough overhead to make it infeasible.

Not so, we are talking about 10s of instructions per millisecond.  All the
rest of the cpu time goes to the application to get useful work done.  The
i/o driver authors are just lazy.