Date: Sat, 9 Sep 95 22:05:27 +0100 From: Jean-Marc Zucconi <jmz@cabri.obs-besancon.fr> To: se@zpr.uni-koeln.de Cc: current@freebsd.org Subject: Re: NCR problem: progress Message-ID: <9509092105.AA15911@cabri.obs-besancon.fr> In-Reply-To: <199509091920.AA16534@Sysiphos> (se@zpr.uni-koeln.de)
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>>>>> Stefan Esser writes:
> On Sep 9, 2:16, Jean-Marc Zucconi wrote:
> } Subject: NCR problem: progress
> } Hi,
> }
> } I have some new data points :-). I tried several combinations and here
> } is the result:
> }
> } 1 streamer + Micropolis2210 OK
> } 2 streamer + Quantum OK
> } 3 streamer + Micropolis2210 + Quantum OK
> } 4 streamer + Micropolis4110 crash
> } 5 Micropolis4110 alone crash
> What are the technical characteristics of the 4110 ?
Capacity
Unformatted
Per drive 1,205 MB
Per Track Variable
Per Surface 133.85 MB
Cylinders 2,428
Formatted
Per drive 1,052 MB
Bytes per Sector 512
Sectors per track Variable
Cylinders 2,415
Performance
Av. seek time 8.5 ms
Av. rot. latency 5.56 ms
rotational speed 5400rpm
data transfer rate at interface
Synchronous up to 10 MB/sec
Asnchronous up to 5 MB/sec
Internal data rate 30-47 Mbits/dec
General Functional specifications
Interface Fast SCSI-2
Supports Full Common Command Set Yes
Drivers/Receivers Single-ended
> Is it possible that it doesn't implement tagged command
> queues correctly ?
don't know.
> } So it seem that I have a problem with the 4110. However, some of the
> } crashes I had did not involve that disk (id#0). One of the crashes
> } occured during a backup of id#4 and the 4110 was not mounted. Is it
> } possible that this disk generate some noise on the bus?
> Possible ...
> Maybe the drive has got an internal terminator that is
> enabled by some jumper ?
There is no internal terminator: termination is done with 2 removable
resistor arrays. I have tried with and without the
terminators (RN1 and RN2 below). The doc says:
"Interface Termination: RN1 and RN2 provide active termination for the
SCSI interface lines. (active termination is recommended when multiple
drives are used on the same SCSI cable) The default is RN1 and RN2
installed. SCSI terminators are installed only in the end devices on
the SCSI cable; remove the terminatorsfrom each of the other
devices. The SCSI Host adapter card and the last drive in the chain
should have terminators."
I have not changed the other jumpers:
" terminator power: W1, W2 and W3 select the source of terminator
power (+5v) for interface terminators RN1 and RN2.
W1 W2 W3
Y drive provides power to rn1 and rn2 (default)
Y host provides terminator power via J1 pin 26 to RN1 and RN2
Y drive supplies +5v to the bus via J1 pin 26"
The other jumpers are for the spindle options, spindle sync
termination and parity (the disk always generate parity, the jumper is
set to parity checking on)
> } I have connected the 4110 to a macintosh (an old SE), formatted it,
> } and I currently make reads/writes with this disk. It works without any
> } trouble (of course that kind of machine will not stress the scsi bus...)
> } I will try to plug the disk to another machine this week-end (I have a
> } friend running linux on a 486/33+ 1542B). What if the disk only fails
> } with the ncr driver?
> If it works with the 1542B and doesn't with the NCR,
> that doesn't prove much (except that using the 1542B
> would give you a working system :)
Indeed, I installed a 1542B on the system and I had no problems!! (3
disks + streamer)
> The 1542B is limited to 5MHz and doesn't use tagged
> commands, AFAIK ...
> You can disable tagged commands for a single target:
> # ncrcontrol -t 4 -s tags=0
> (sets max. 0 tags (i.e. send no TAG message at all)
> for target 4).
Ok - I reconnect the drive and try this (with -t 0 since the 4110 is
target 0)
> Regards, STefan
Jean-Marc
> --
> Stefan Esser, Zentrum fuer Paralleles Rechnen Tel: +49 221 4706021
> Universitaet zu Koeln, Weyertal 80, 50931 Koeln FAX: +49 221 4705160
> ==============================================================================
> http://www.zpr.uni-koeln.de/staff/esser/esser.html <se@ZPR.Uni-Koeln.DE>
_____________________________________________________________________________
Jean-Marc Zucconi Observatoire de Besancon F 25010 Besancon cedex
PGP Key: finger jmz@cabri.obs-besancon.fr
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