Ethan's Retrocomputing Corner
classiccmp: Formatting Disk On RT11
Date: Sat, 05 Jun 1999 17:48:25 -0400
From: Jerome Fine
Subject: Re: Formatting disk on rt11
>Allison J Parent wrote:
> > Technically, I suppose Allison is correct, but I have
> > never heard of anyone writing their own version of ZRQC??
> No, I am correct. there is no formatter for RDxx drives under RT-11.
> XXDP does it really well but that is NOT RT-ll.
Jerome Fine replies:
I agree to agree!! I think we agree completely, but are just using
different words. Since XXDP has both ZRQB?? (for RD51,2,3
drives) and ZRQC?? (for RD54 drives), then I doubt anyone
would bother at this point to write their own utility to run under
RT-11.
> There is a lot of work but writing a utility to format a RD under
> RT-11 is possible, though if you have the tools and info to do that
> you also know XXDP is available.
So we just use the XXDP version since we don't need to FORMAT
a drive all that often any more.
> > Just a note of clarification (again, Allison this is not a flame that you u
> > but just correcting your "spelling" - anyone who knows realizes and anyone
> > who doesn't understand - it doesn't matter). Allison was referring to the
> > SET DUn: UNIT=u, PART=p
> Actually I've never used a RD larger than 31mb on an RT11 system so the
> SET DUn would not have come to mind. Why no big disks? I have MANY
> MANY RD52s and an RD53/54 would be VAX fodder.
>
> Also while RQDX3s are RD54 aware, some of the RQDX1 and 2s are very much
> unaware of the RD54 and will produce errors.
I believe that an M8639 (RQDX1) will handle an RD51.
I think you need an M8639-YA to also handle an RD52.
I believe that an M8639-YB (RQDX2 - similar in some ways
the the RQDX1, but also very different) can handle up to an RD53 which
is about 70 Mbytes. I don't thank that any RQDX1 or RQDX2 will recognize
an RD54.
The RQDX3 (M7555) is needed to handle the RQDX3 - leave it to DEC
to make things difficult and costly.
On the PDP-11 I have available, there are 3 * Hitachi DK515-78 or almost
2 GBytes. These are ESDI drives on a Sigma RQD11-EC quad MSCP
controller which can run 4 drives and has 1 MByte of cache. The system
uses V5.6 with Y2Y patches and can look at all 60 partitions on the
3 drives (of which 2 are used only for backup). Plus the DUX.SYS
device driver boot block code has been modified so that all 60 partitions
can be booted if so desired. The standard distributed book block from
DEC could boot only DU0: to DU7: and it was a pain not to be able to
boot the partitions on the other drives.
Sincerely yours,
Jerome Fine
Date: Sat, 05 Jun 1999 17:56:55 -0400
From: Jerome Fine
Subject: Re: Formatting disk on rt11
>Allison J Parent wrote:
> > Believe it or not, it is possible to FORMAT an RX33 floppy under RT-11!
> > Just a little side note which has nothing to do with the original question
> > Also, you can't FORMAT an RX50 under RT-11 and it is much easier to
> > FORMAT the RX50 floppy on a PC. Shout if you want instructions how!
>
> Both would handy to know as doing it under xxdp is terminally slow.
Jerome Fine replies:
> From actual first hand experience, I have been able to do a FORMAT for
an RX33 directly under RT-11. I believe it was at least V5.4G and may
have even been V5.6 of RT-11. OF COURSE, ONLY an RQDX3
controller can manage an RX33 floppy. And you MUST use HD 1.2 MByte
(from the PC point of view) floppies.
As a matter of note, I purchased 2 RX33 floppy drives and placed both
inside the empty shell of a dual RX50 drive with the black plastic sled
underneath everything. That provides a very nice package. There is
just enough room at the rear of the RX50 shell to hold the 34 pin cable
with daisy chained edge connectors to both RX33 drives (DO NOT
USE a twist in the 34 pin flat cable to select the second drive, I used
the jumpers on the RX33 drive itself to select the second unit) along
with a Y power connector to both RX33 drives. The normal holes
in the RX50 shell allow both the cables easy access outside the shell.
Tim Shoppa just noted that V5.7 of RT-11 allows an RX50 floppy drive
to FORMAT under RT-11, but I am not aware if that is for EVERY
RX50 floppy drive, OR ONLY the special ones that have been noted
as being able to do a FORMAT on a Rainbow. Either you (Allison)
or Megan Gentry or someone else mentioned that recently. And I
don't know if all RQDX1,2,3 are included.
With regard to a FORMAT in the RT-11 world, we should define
our terms since the PC world FORMAT also includes what in RT-11 is
the separate operation called "INIT". John Wilson has written a
wonderful utility PUTR (Peripheral Utility Transfer Routine) which
has a FORMAT command for 5 1/4" floppy diskettes which produces
the RX50 format - 10 sectors per 80 tracks. Note that the DEC RX50
floppy is the media identical the to PC 5 1/4" DSDD 360 KByte floppy
which I understand is 9 sectors per 40 tracks (wide ones) on both sides.
The RX50 is on 80 narrow tracks on ONLY one side. BUT if you are
doing the FORMAT on a PC, you must still use a 1.2 MByte HD floppy
drive to do the FORMAT operation since the RX50 requires the narrow
tracks. You can download the FREE version (all versions are FREE)
(that runs on a PC under DOS/W95/W98) of PUTR from:
http://www.dbit.com/pub/putr/
Shout if you have any more questions!!
I posted this in the public list as well since I suspect that
others may be interested. An apology to Allison if I should
have asked permission to quote her first!
Sincerely yours,
Jerome Fine
Date: Sun, 6 Jun 1999 9:18:41 -0400
From: Tim Shoppa
Subject: Re: Formatting disk on rt11
>>RX50 formatting under RT-11 V5.7 (i.e. FORMAT/SINGLE DUn:) only is
>>supported on certain 3rd-party controllers like the Andromeda ESDC and
>>SCDC. It doesn't work with RQDX1/2/3's.
>Regarding my prior message, I stand corrected...
Well, in *this* particular case, Mentec arranged for Andromeda to
give me a SCDC controller with some SCSI drives and 5.25" and 3.5" floppies,
and that's the reason why the Andromeda is supported for this operation
under RT-11 5.7 :-).
>But even though an RQDX3 is not required (or useful) for this, I'll
>suspect an RX33-type drive still is. Is that correct, Tim?
Not necessarily. I just hooked a true DEC RX50 to my SCDC, configured
it, and it still lets me do a RX50 format:
SCDC User Service Port V3.06
B Configure controller HARDWARE JUMPERS
D Display/define physical DRIVE PARAMETERS
A Assign logical DU/MU UNITS
C Configure controller SOFTWARE OPTIONS
E Exercise a SCSI DISK drive
F FORMAT a DISK drive
P RESET controller and EXIT
? d
SCSI or Floppy (S or F)? f
Floppy drive number (0 or 1)? 0
Floppy drive 0: 800 blocks
Floppy drive types:
76 3.5" 80 track DS
134 5.25" 80 track DS
420 DEC RX50 dual drive
Floppy drive type (76, 134, or 420) [134]? 420
SCSI or Floppy (S or F)?
SAVE CHANGES- Are you sure (Y or N) [N]? y
SCDC User Service Port V3.06
B Configure controller HARDWARE JUMPERS
D Display/define physical DRIVE PARAMETERS
A Assign logical DU/MU UNITS
C Configure controller SOFTWARE OPTIONS
E Exercise a SCSI DISK drive
F FORMAT a DISK drive
P RESET controller and EXIT
? f
SCSI or Floppy (S or F)? f
Floppy drive number (0 or 1)? 0
Floppy drive 0: (offline)
Available floppy formats:
DD 800 blocks
Which format (# of blocks)?
Now whether you want to actually do the format on a DEC RX50 drive is
another question. According to Charles Lasner's voluminous posts on RX50
technical details, RX50 drives lack the required physical head-positioning
accuracy to make a RX50 floppy that's guaranteed to be interchangable with
other drives. Look at Charles's posts to alt.sys.pdp8 on the topic
from 4-5 years ago for more details about his tests.
--
Tim Shoppa Email: shoppa@trailing-edge.com
Trailing Edge Technology WWW: http://www.trailing-edge.com/
7328 Bradley Blvd Voice: 301-767-5917
Bethesda, MD, USA 20817 Fax: 301-767-5927
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