Path: utzoo!mnetor!uunet!husc6!bbn!bbn.com!levin
From: levin@bbn.com (Joel B Levin)
Newsgroups: comp.sys.mac
Subject: Jasmine Direct Drive 50 and a Plus
Message-ID: <23013@bbn.COM>
Date: 5 Apr 88 19:05:02 GMT
Sender: news@bbn.COM
Reply-To: levin@BBN.COM (Joel B Levin)
Organization: BBN Communications Corporation
Lines: 42

I just got a Jasmine Direct Drive 50 for the office Plus, and I wanted
to pass along a small gotcha that you might keep in mind if you are
looking at hard disks.

One of the reasons I chose this particular drive, besides the Jasmine
reputation for quality of product, support, and reliability, was the
reported performance mentioned here in this forum and by a colleague
who got the same drive.  After I got it hooked up and started
exploring the shareware/freeware folders, I found disktimer II and ran
it.  I was surprised to find the performance numbers substantially
lower than I had been led to believe they would be:

  Read   117
  Write  126
  Seek     0 (no seeking due to the large number of sectors per
              cylinder, I believe).

I called Jasmine Tech Support and discovered that the drive is
formated with 1:1 interleave; that it comes from the factory that way;
and that the interleave cannot be changed by software, according to
the person who answered my call (and consulted with someone while I
was on the phone to verify that this was normal performance).

On a more positive note, I took the drive home and tried it on an SE.
The numbers were 34, 51, and 0 -- much more like what I had expected
(the SE internal HD20 was 76, 76, and something).  So my drive is in
fact functioning properly, it seems.

On a further positive note, it is still a great improvement over the
floppy port Apple HD20 I had been using (a factor of >3 over the
disktimer times, and a factor of 1.8 - 2.0 for things like launching
large programs).  And the drive is quiet and seems reliable and in all
other respects meets my expectations.

Bottom line: the DD50 appears to be everything they say it is, though
if you are looking for a drive to attach to a Plus you should consider
whether it is capable of being tuned to run at its optimum speed.

	/JBL
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