From: wayne@amtower.spacecoast.org (Wayne Summer)
Subject: Re: IDE vs SCSI
Distribution: world
Reply-To: wayne@amtower.spacecoast.orgX-NewsSoftware: GRn 1.16f (10.17.92) by Mike Schwartz & Michael B. Smith
Organization: Wayne's Machine; Palm Bay, Florida
Lines: 33

In article <1993Apr15.235509.29818@julian.uwo.ca> wlsmith@valve.heart.rri.uwo.ca (Wayne Smith) writes:
>
> I won't argue that the SCSI standard makes for a good, well implimented
> data highway, but I still want to know why it intrinsically better
> (than IDE, on an ISA bus) when it comes to multi-tasking OS's when
> managing data from a single SCSI hard drive.

I have been following this thread and figured I'd throw in my two cents...

The Amiga Zorro II bus is comparable with the ISA bus (7.16 vs 8.33 MHZ).
The Amiga has had a pre-emptative multi-tasking  OS since '85 and can
operate with 1 MB RAM!  SCSI is used almost exclusively on these systems.

A SCSI controller that transfers data by DMA allows the cpu to request data
from the hard drive and continue working while the controller gets the data
and moves it to memory.  A controller that allows reselection can operate
even better with multiple devices.  This is espically true with SCSI tape
units.  For example, when rewinding or formatting a tape, the command is
issued to the controller and the bus is released to allow access to other
devices on the bus.  This greatly increases productivity or, at least, do
something else while backing up your hard drive :-).  Which happens to be
what I am doing while reading this group.

Its a long story, but I still use IDE on my 486 except for the CDROM which,
thanks to SCSI, I can move between both machines.  If, and when, SCSI is
better standardized and supported on the ibm-clone machines, I plan to
completely get rid of IDE.
--
  Wayne Summer        //        AMIGA - Simply the Best.
  Palm Bay, FL. US  \X/        wayne@amtower.spacecoast.org

Quote of the week: Don't hate microsoft because because they are microsoft,
though...hate them because their products are lame - Found in c.s.ibm.pc.misc