Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!bloom-beacon!mit-eddie!uw-beaver!tikal!arnie
From: arnie@tikal.Teltone.COM (Arnold Koster)
Newsgroups: comp.sys.amiga.tech
Subject: Re: ST-251 in a PAL Jr.
Keywords: disk,odd behavior
Message-ID: <966@tikal.Teltone.COM>
Date: 21 Jun 88 07:35:43 GMT
References: <476@amanpt1.zone1.com>
Reply-To: algedi!kenk@pilchuck.Data-IO.COM ( Ken  Koster)
Organization: Teltone Corp., Kirkland, WA
Lines: 65


 In a previous article 


> I just installed a Seagate ST-251 (40 MB) drive in my PAL Jr. expansion box
> (Remember it?  I bought it just before Byte-by-Byte stopped making them, also

  Remember the PAL sr. ?

> The "problem" I'm about to describe is essentially a perceived substantial
> increase in seek activity.  I say "perceived" since I have no measurements

> Each time I invoke a disk-resident command, there is a long (.25 - .5 seconds)
> period of seek activity with a very distinct "audio" pattern to it (I think

> during the (very long) formatting process.  This was done with a program
> supplied by Byte-by-Byte, named "hdtest".  Indeed, the blocks described as

> If you're still reading, thanks for being patient.  If you've had similar

  Anything about the PAL/PAL Jr. I read.

> discoveries with me.  You don't have to be a PAL Jr. owner (hell - I'd never
> hear from anybody!).  Is there a disk activity monitoring tool I can use to

    You'll have to settle for a PAL Sr owner.

    I have a PAL expansion box with the same HD controller as in the PAL JR.
  It was one of the first 24 built (maybe the only 24 built :-) ) and has
  performed flawlessly for almost 2 years. However I did experience a 
  similar problem with the Seagate ST-225 drives on mine. If you have a version
  of the disk driver that parks the heads after a few seconds of inactivity,
  disable it. Parking the heads requires that the driver seek from the parking
  track to the desired location. According to Murphy this will always be the
  opposite end of the disk thus requiring a long seek. It is the sound of 
  this seek that you hear. I found that by NOT parking the heads on my drives
  the problem went away. 

    In addition get a copy of the driver and utility software supplied with
  the Commodore 2090 controller. (i.e. hddisk v33 rev 18 and Prep ). Use 
  hddisk for the driver and Prep to prepare the drive. The 2090 and the 
  Byte by Byte controller seem to be identical in design ( if someone knows 
  the full story I'd like to hear it ) with the exception of the SCSI 
  interface which is only complete on the 2090. Using hddisk fixes a bug in
  using overscan screens and also appears to be somewhat faster than the 
  supplied driver. I have been using this combination since last fall with 
  no problems at all.

  Of course if your driver does not park the heads this is all food for the
  bit bucket :-)
 
  Hope this helps - now if I can only get the SCSI port to work :-)
                    and autoboot hacked in for 1.3 :-)

> 	Thanks in advance
> 		Mark

  Your Welcome
 

Ken Koster (N7IPB)     algedi!kenk@pilchuck.Data-IO.COM		or
12653 NE 95th       ...uunet!pilchuck!algedi!kenk		or
Kirkland,Wa 98033   ...uw-beaver!tikal!pilchuck!algedi!kenk
						
Mine all Mine. Hee Hee :-) :-)		Amiga,1.5meg,40megHD,UUPC