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From: visinfo@ethz.UUCP (VISINFO Moderators)
Newsgroups: comp.sys.amiga.tech,comp.sys.amiga
Subject: Re: Pal, Jr. HD controller info needed
Summary: SCSIformat is coming soon
Keywords: SCSI 2090 Harddrive
Message-ID: <1492@ethz.UUCP>
Date: 5 Jul 89 10:57:25 GMT
References: <727@orbit.UUCP>
Reply-To: visinfo@bernina.ethz.ch.UUCP (VISINFO Moderators)
Organization: ETH Zuerich, Switzerland
Lines: 60

In article <727@orbit.UUCP> baxt@pnet51.cts.com (Bill Backstrom) writes:
>>In article <292@titan.tsd.arlut.utexas.edu> lofaso@titan.UUCP (Bernie Lofaso)
>writes:
>>>I have a PAL, Jr. expansion chassis for my A1000. This unit has what is
>>>essentially a 2090 hard disk controller on a Zorro I form factor.  I'm using
>>>it with an ST506 interface (a Seagate ST225 disk). Although I have been
>>>happy with the unit, after running DiskPerf I found that I was actually
>>>getting pretty slow transfer rates - about 50k/sec.  My disk is formatted
>>>with the FFS and is running 1.3.  I have read postings of much higer
>>>transfer rates...

I don't know if you could speed up ST506 drives. The ST506 standars is much
slower than SCSI. So I my utilities will only work with SCSI drives.
Sorry, but this IBM standard is really to bad to use it for professional
usage on the AMIGA.

>I have a B2000 with a 2090 and a ST296N (85 meg SCSI). I'm running
>1.3, definitely using FFS (512 byte blocks) and version 34.4 of
>hddisk.  
>
>Diskperf gives me a reads of about 80K bytes/sec and writes of 155K
>bytes/s for 32K blocks. I've also had an ST125 (20 meg ST-506) on the
>controller and got reads of 165K bytes/s and writes of 120K bytes/s. 
>Nothing special is going on - no hi-res with overscan and interlace,
>etc.

That's probably because of the Low-level Interleave inside the SCSI drive.
You cannot change this with Prep.

>I have tried different interleaves, another 2090 card, and various
>partition sizes. Nothing has improved the performance. The only
>unusual thing I've noticed apart from the low data transfer rates is
>that I could not prep the drive with my controller, I had to use my
>dealer's 2090A. 

Different Interleaves in the mountlist don't affect the transfer between
the SCSI device and the 2090. This interleave is only for DOS internal use.
I have never seen any device that uses this Interleave. I always set it to
zero.

>I'm out of ideas and would appreciate any suggestions (of course
>sympathy is always welcome too). Thanks. 

>Bill Backstrom

Solution: Format the drive not with PREP. Prep always uses the built in
Interlave which is usually 1. (Seagates are generally slow with Interleave 1).
I hope I can release an early version of my SCSIformat this or next week.

The problem currently is that I haven't written an SCSIprep yet which writes
the cylinder 0 datas for automount/-boot after the low-level format. You
could prep your hd and then save the infos from cyl 0 and 1, then format
your hd with SCSIformat and restore the infos.


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