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From: info-mac@uw-beaver (info-mac)
Newsgroups: fa.info-mac
Subject: Hard disks for MAC and applebus -- User beware.
Message-ID: <1216@uw-beaver>
Date: Fri, 13-Jul-84 15:54:43 EDT
Article-I.D.: uw-beaver>.1216
Posted: Fri Jul 13 15:54:43 1984
Date-Received: Sun, 15-Jul-84 01:11:33 EDT
Sender: daemon@uw-beave
Organization: U of Washington Computer Science
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From: imagen!geof@su-shasta.arpa

I spoke to an Apple-person at NCC Wednesday.  He indicated that there
were four hard disk products out there for the MAC (I didn't go into
names).  Two use direct, non-applebus connections to the MAC.  One uses
an applebus-compatible connection to the MAC.  One uses the `second
disk' port.

There is only one applebus port on the MAC.  Thus if your hard disk (or
whatever) doesn't use an applebus-compatible protocol to talk to that
port, you can't run applebus on the MAC while that peripheral is hooked
up (applebus-compatible does not necessarily mean that it can be shared
with other macs on the ABus, just that it knows how to live in that
multi-drop environment).  User beware.

Because applebus is pretty slow as nets (and hard disks) go, it is
probably the case that the applebus-compatible disk is slower to access
than the others.  The disk that used the disk port seemed to me to be
the best compromise, although I don't really know the details.


- Geof Cooper
  Imagen