[comp.unix.xenix] RLL and Xenix

jack@turnkey.TCC.COM (Jack F. Vogel) (05/09/88)

In article <496@megatest.UUCP> palowoda@megatest.UUCP (Bob Palowoda) writes:
>in article <609@mccc.UUCP>, pjh@mccc.UUCP (Pete Holsberg) says:
>> 
>> I can't tell you what to buy, but I CAN tell you that the Micropolis
>> 1335 drive with a DTC 5380 (maybe 5280) controller tests VERY slow, as
>> reported by the InfoWorld benchmark program.  And the 1335 is reputed to
>> be a 28 ms drive!
>
>   Interesting my DTC controller seems to be slow also. 
[details on performance deleted]

  I find it interesting that both of you seem to have performance problems with
the DTC controller; I am quite sure it is the controller and not the drives.
We are using two Micropolis drives, one 60 and one 70 Meg (I always forget the
model numbers) with the WD1003RA controller, this formats out to a shade over
200Meg. Now we have no DOS partitions so I have not run the Core test, but
performance empirically seems far improved over MFM.
  Xenix is working great with this combination. I think it is even easier to 
set up than a DOS system would be. You need no special software or bios
entries to deal with the 26 sectors. You just leave the cmos set up as 17
sectors and when installing the system you just tell hdinit the proper
parameters and it all works!!
  I was wondering, how do you have the drives interleaved? Does the DTC have
a track buffer? The WD controller does not so I set up a 2 to 1 interleave.
Perhaps running a 1 - 1 is causing the slowdown. Just a thought.
  If anyone out there would like more information or has questions about using
RLL with SCO just send me some mail and I will be happy to answer whatever
questions I can.

						Best regards,




-- 
Jack F. Vogel
Turnkey Computer Consultants, Costa Mesa, CA
UUCP: ...{nosc|uunet}!turnkey!jack 
Internet: jack@turnkey.TCC.COM

pjh@mccc.UUCP (Pete Holsberg) (05/10/88)

In article <199@turnkey.TCC.COM> jack@turnkey.TCC.COM (Jack F. Vogel) writes:
...  I find it interesting that both of you seem to have performance problems with
...the DTC controller; I am quite sure it is the controller and not the drives.
...We are using two Micropolis drives, one 60 and one 70 Meg (I always forget the
...model numbers) with the WD1003RA controller, this formats out to a shade over
...200Meg. Now we have no DOS partitions so I have not run the Core test, but
...performance empirically seems far improved over MFM.

When I changed the interleave, CORETEST showed that the performance of
the DTC 5280 and Micropolis 1335 were on the money for an ST-506 system.
However, benchmarks that attempt to test realistic situations show this
combo to be fairly slow.  It's not clear that the DTC controller is the
culprit. 

...  I was wondering, how do you have the drives interleaved? Does the DTC have
...a track buffer? The WD controller does not so I set up a 2 to 1 interleave.
...Perhaps running a 1 - 1 is causing the slowdown. Just a thought.

3:1 is required by Microport V/386, but 3:1 is the interleave that shows
the poorer performance.  The DTC controller is fairly inexpensive ($150
and it also controls 2 floppies) so I would be surprised if it had full
track buffering.

...  If anyone out there would like more information or has questions about using
...RLL with SCO just send me some mail and I will be happy to answer whatever
...questions I can.

:-)  What are the model numbers of your Micropolis drives?