bill

--
Bill Gunshannon          |  de-moc-ra-cy (di mok' ra see) n.  Three wolves
bi...@cs.scranton.edu     |  and a sheep voting on what's for dinner.
University of Scranton   |
Scranton, Pennsylvania   |         #include <std.disclaimer.h>  

Bill Gunshannon <bi...@triangle.cs.uofs.edu> writes:
> Is there any way to format non-DEC disks for use with the RQDX3??
> I get the (obvious) message that the disk is unknown when I try to
> format anything other than RD disks.  I don't have many RD's left,
> but I am sure I can still find other MFM type disks.

  If you have a disk that has at least the same number of cylinders and
heads as a RDxx disk, you can tell the formatter to treat it as that
RDxx disk. This only works on the RQDX3, the RQDX1/2 attempt to guess
the disk type and you can't override it.

  For an example, see:
http://eisner.decus.org/DECUServe/DECnotes/HARDWARE_HELP/93.51.HTML

  You can also define a completely new geometry from scratch, but you
need some info on MSCP internals and you can get into trouble (disk
corruption) if the drive ever does bad block replacement.

        Terry Kennedy             http://www.tmk.com
        te...@tmk.com             New York, NY USA

>   You can also define a completely new geometry from scratch, but you
> need some info on MSCP internals and you can get into trouble (disk
> corruption) if the drive ever does bad block replacement.

Bad block replacement on a ST506 disk !? First time I head of that..

--
    Martijn van Buul -  Pi...@dohd.org - http://www.stack.nl/~martijnb/
         Geek code: G--  - Visit OuterSpace: mud.stack.nl 3333
   Kees J. Bot: The sum of CPU power and user brain power is a constant.

Martijn van Buul <pie...@c64.org> writes:
> Bad block replacement on a ST506 disk !? First time I head of that..

  Yup. All MSCP disks are logically defect-free. Depending on the MSCP
controller type, bad block replacement is either done in the controller
or by the host with assistance from the controller.

        Terry Kennedy             http://www.tmk.com
        te...@tmk.com             New York, NY USA

> Bad block replacement on a ST506 disk !? First time I head of that..

What else would you do when a block goes bad?  Presumably you don't want
to just keep using a bad block in the middle of a file?

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This is zrqch0 from XXDP hacked to believe that a Maxtor XT1140
(the 918 track little brother of the XT2190) is an RD54. The
XT1140 boots 2.11BSD now.

I'm still working on it, but I think I've almost got the method
for hacking the tables in ZRQCH0 for any MFM drive. I'm not just
changing the number of tracks, but recalculating all the
parameters: revector table sizes and everything. There are still
some things in the table I can't figure out, but it seems to
work.

--
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----- Original Message -----
From: "Bill Gunshannon" <bi...@triangle.cs.uofs.edu>
To: <info-...@village.org>
Sent: Monday, January 07, 2002 10:26 AM
Subject: RQDX3 + XXDP + Non-DEC Disks

> Is there any way to format non-DEC disks for use with the
RQDX3??
> I get the (obvious) message that the disk is unknown when I
try to
> format anything other than RD disks.  I don't have many RD's
left,
> but I am sure I can still find other MFM type disks.
>

> bill
>
> --
> Bill Gunshannon          |  de-moc-ra-cy (di mok' ra see) n.
Three wolves
> bi...@cs.scranton.edu     |  and a sheep voting on what's for
dinner.
> University of Scranton   |
> Scranton, Pennsylvania   |         #include <std.disclaimer.h>

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the quotes).
>

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On 8 Jan 2002, Martijn van Buul wrote:

> It occurred to me that Terry Kennedy wrote in vmsnet.pdp-11:
> >   You can also define a completely new geometry from scratch, but you
> > need some info on MSCP internals and you can get into trouble (disk
> > corruption) if the drive ever does bad block replacement.
>

> Bad block replacement on a ST506 disk !? First time I head of that..

Yup. And that's why the disk needs to be setup specialle before an RQDX3
will use it.
All MSCP devices do bad block replacement. The underlying technology used
is irrelevant. So you have MFM, SDI, SCSI, DSSI, SMD and perhaps some
other low level formats for MSCP controllers.

        Johnny

Johnny Billquist                  || "I'm on a bus
                                  ||  on a psychedelic trip
email: b...@update.uu.se           ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol

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It occurred to me that Terry Kennedy wrote in vmsnet.pdp-11:

> Martijn van Buul <pie...@c64.org> writes:
>> Bad block replacement on a ST506 disk !? First time I head of that..
>
>   Yup. All MSCP disks are logically defect-free.

Logically defect-free, okay. But the controller should take care of that,
in the case of an RQDX3 controller, not the drive..

--
    Martijn van Buul -  Pi...@dohd.org - http://www.stack.nl/~martijnb/
         Geek code: G--  - Visit OuterSpace: mud.stack.nl 3333
   Kees J. Bot: The sum of CPU power and user brain power is a constant.

Martijn van Buul <pie...@c64.org> writes:
> Logically defect-free, okay. But the controller should take care of that,
> in the case of an RQDX3 controller, not the drive..

  Ah. I see the problem now. My imprecise usage of English. Let me try again:
"... if the drive ever undergoes bad block replacement".

        Terry Kennedy             http://www.tmk.com
        te...@tmk.com             New York, NY USA

At 05:21 PM 1/9/2002 GMT, Martijn wrote:
>>> Bad block replacement on a ST506 disk !? First time I head of that..
>>   Yup. All MSCP disks are logically defect-free.

>Logically defect-free, okay. But the controller should take care of that,
>in the case of an RQDX3 controller, not the drive..
>

By the way I think Bill Gunshannon started this thread.  If still looking for
info, the RQDX3UG1.pdf is showing up in the listing at
http://208.190.133.201/decimages/moremanuals.htm
It tells how to format standard disks, but its 29Mb so be patient.
http://www.ibiblio.org/pub/academic/computer-science/history/pdp-11/hardware
/mfm.disks
gives some of the paramters required for a non-standard VS2000 format
but I don't know if you can get to these options with XXDP on a PDP-11.

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> At 05:21 PM 1/9/2002 GMT, Martijn wrote:
>>>> Bad block replacement on a ST506 disk !? First time I head of that..
>>>   Yup. All MSCP disks are logically defect-free.
>>Logically defect-free, okay. But the controller should take care of that,
>>in the case of an RQDX3 controller, not the drive..
>>
> Aren't we nit picking a little here.

Not intentionally. "Confused" was a better description.

--
    Martijn van Buul -  Pi...@dohd.org - http://www.stack.nl/~martijnb/
         Geek code: G--  - Visit OuterSpace: mud.stack.nl 3333
   Kees J. Bot: The sum of CPU power and user brain power is a constant.