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Date:      Fri, 6 Aug 1999 10:16:05 +0100 
From:      Nigel Roles <ngr@symbionics.co.uk>
To:        "'Kevin'" <kbock@primenet.com>, freebsd-scsi@FreeBSD.ORG
Subject:   RE: DC-390U2W support, continued
Message-ID:  <1E485299309FD211A2100090271E27A41431B3@symnt3.cadence.com>

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http://www.freebsd.org/cgi/getmsg.cgi?fetch=117140+119343+/usr/local/www/db/
text/1999/freebsd-scsi/19990207.freebsd-scsi

This email explains one of the problems. The kernel is limited to 20MHz by

#define SCSI_NCR_DFLT_SYNC 12

If you set this to (10), or put

options         SCSI_NCR_DFLT_SYNC=10

before rebuilding, it will do 40Mhz. This is because 10 means 40Mhz, 11,
33Mhz, and 12,
20Mhz.

However, if you check the CVS repository, there are some issues to do with
the microcode.
The 3.2 release has ncr.c version 1.141.2.1. The main line version 1.146 has
a change to the
microcode to stop using a register which used to be free, but now has a
meaning. In principle this should affect all chips from the 875 onwards, but
it is clear that people often get away with it.

-----Original Message-----
From: Kevin [mailto:kbock@primenet.com]
Sent: Friday, August 06, 1999 9:51 AM
To: freebsd-scsi@FreeBSD.ORG
Subject: DC-390U2W support, continued


Hey, sorry for my previous stuipidity.. here's my problem..

The Tekram BIOS says the drive is 80Mb/sec wide, which it is (IBM UltraStar
9ES)

here's an output from FreeBSD 3.2-STABLE (8/5/99)

ncr0: <ncr 53c895 fast40 wide scsi> rev 0x01 int a irq 11 on pci0.19.0 
..
da1 at ncr0 bus 0 target 6 lun 0
da1: <IBM DDRS-39130D DC1B> Fixed Direct Access SCSI-2 device
da1: 40.000MB/s transfers (20.000MHz, offset 15, 16bit), Tagged Queueing
Enabled
da1: 8715MB (17850000 512 byte sectors: 255H 63S/T 1111C)
...

It is connected to the "J1" connector which is 68-pin 16-bit WIDE Ultra2
internal SCSI connector, via a twisted-pair cable with the Ultra2 LVD
terminator, supplied with the controller, at the end..

why is FreeBSD only saying 40Mb/sec, 20Mhz? I was told you need 40Mhz in
order to obtain the 80Mb/sec transfer rate.. which FreeBSD only says
40Mb/sec.. what is with this picture? 

Please reply to me directly as I am not subscribed to this list.

Thanks,

Kevin



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