[Simh] DG Nova booting from another file or "device"?

Microtech Dart microtechdart at gmail.com
Thu Nov 19 22:37:36 EST 2015


Thank you, Bruce...this is absolutely fantastic information.

I'm going to try to spend a few more days attempting to correct the handful
of block errors that I have, and then send those files over.  The sizes you
mention for the LU files appear to be, at first glance, exactly what I
have.  This confirmation is all very good.

So, the bootable Minicom utility file must have some kind of "last backup
stored data/memory" embedded within it, right?  Otherwise, how would it
know all of that stuff?

I wonder, is there a date in there anywhere that indicates the date the
backup was done?

Thanks again!

-AJ

On Wed, Nov 18, 2015 at 2:55 PM, Bruce Ray <Bruce at wild-hare.com> wrote:

> G'day AJ -
>
> Creating a separate disk file that contains the contents of one of the
> tape files is okay.  We can figuratively 'stitch" the files together into a
> format compatible with SimH by using some of our own utilities.
>
> Since the DiskUtility is transfers data on a block-for-block basis, all
> tape records must be recognized even if the record contains errors.
> Otherwise, the required relative position between tape and disk "records"
> will become lost.  Error records can be indicated a variety of ways, so
>
> According to a quick calculation, the LUN byte sizes can be calculated
> from the previously-provided LUN "partition" info as:
>
> LUN 0:  1,310,720
> LUN 1:  7,864,320
> LUN 2:  9,175,040
> LUN 3:  9,175,040
> LUN 4:  8,683,520
>
> LUN 0, 1 and 2 can fit on boot tape according to DiscUtility hints, LUN 3
> and 4 fit on separate (2nd) backup tape.
>
>
> Bruce
>
>
> On 11/18/2015 10:40 AM, Microtech Dart wrote:
>
>> "What other file(s) am I missing?"  I haven't sent the other 3 LU files
>> on the tape yet.  Sorry, I should have made that more clear.  Also, I
>> didn't show the filemarks I was speaking of, that is where I ended one
>> file and started the next, when I constructed them from the bits on the
>> tape.
>>
>> Please keep in mind that I wrote the program that does this, so the
>> method of what I'm doing here is understandably confusing...I barely
>> understand it.
>>
>> There are a few block errors that I'm working on correcting in each of
>> the files..  Shall I send those over to you even with the handful of
>> block errors, or shall I continue to work on correcting them?
>>
>> I just looked at the first paragraph of your email...I'll read the rest
>> now.
>>
>> On Wed, Nov 18, 2015 at 11:29 AM, Bruce Ray <Bruce at wild-hare.com
>> <mailto:Bruce at wild-hare.com>> wrote:
>>
>>     G'day AJ -
>>
>>     There is only one program on the 'MinicomDiskUtility.bin' file -
>>     there is no data beyond the 8KB (the file size is only). There is no
>>     "filemark" or other pseudo-/meta- data that I detect in the file,
>>     just a single stream of 4096 words (as appropriate for the DG
>>     word-oriented architecture [big-endian]).  What other file(s) am I
>>     missing?
>>
>>
>>     Regardless, dissecting and running the utility reveals further
>>     program assumptions:
>>
>>     The 40 MB disk drive has a geometry of 442 cylinders, 5 heads, 32
>>     sectors/track (head).
>>
>>     The IRIS logical unit to physical disk address assignments are:
>>
>>
>>     LUN     CYL   HD  SEC
>>     ----    ---   --  ---
>>
>>     LUN 0:    0,   0,   0    disk start address
>>               15,   4,  31    disk end   address
>>
>>     LUN 1:   15,   0,   0
>>              111,   4,  31
>>
>>     LUN 2:  112,   0,   0
>>              223,   4,  31
>>
>>     LUN3:   224,   0,   0
>>              335,   4,  31
>>
>>     LUN4:   336,   0,   0
>>              441,   4,  31
>>
>>
>>     Total disk formatted size:  36,308,640 bytes
>>
>>     Data is transferred to/from the disk to the tape drive in 4KB
>>     records during backup/restore operations.
>>
>>     Only logical units 0, 1 and 2 can fit on a tape; a second tape was
>>     required for backing up logical units 3 and 4.
>>
>>     Next step: obtain data files that contain the LUNx information...
>>
>>
>>     Bruce
>>
>>
>>
>>     On 11/18/2015 2:21 AM, Microtech Dart wrote:
>>
>>         Bruce!  This is very exciting...you actually RAN the file!  I'm so
>>         excited to know that this is possible.
>>
>>         I received the screen shots in my MightyFrame email, thank you
>>         for those.
>>
>>         Most of what you are talking about is still Greek to me, but
>>         I'll catch up.
>>
>>         "The tape file itself needs to be created in the SimH tape if it
>>         is to
>>         be used with the default SimH tape driver. The QIC format may
>>         exist as a
>>         single large data record of 16,384 bytes, or of multiple 512-byte
>>         records followed by a file mark. (I can not tell its original
>> format
>>         given only the .bin file to work with.)"
>>
>>         OK, so I know exactly how the data format was written to this
>> tape.
>>            (For detail on the format itself, I outline it in exhaustive
>>         detail on
>>         this page: http://bit.ly/1RhcdK2  )  The format is neither
>>         QIC-11 nor
>>         QIC-24, but some very weird format that I've traced back to a
>>         specific
>>         model of Kennedy QIC tape drive.
>>
>>         The Minicom Disk Utility file that you ran was in one single
>>         block of
>>         data, which was 8192 bytes long.  It was, as you indicate, the
>> very
>>         first block of data on the tape.  This block was followed by a
>>         filemark.
>>
>>         The next block after the filemark was also 8192 bytes (with
>>         nearly, but
>>         not exactly the same content as this Minicom utility file), but
>>         thereafter, every other block on the tape was only 4096 bytes
>>         long, as
>>         was all of the other blocks on the entire tape. (Notice that this
>> is
>>         either 8 or 16 times the length of a "normal" QIC-11 or QIC-24
>>         512-byte
>>         data block).
>>
>>         This tape was marked "LU0, position 1; LU1, position 2; LU2,
>>         position
>>         3", so I expect this tape to have those 3 logical units on it.
>>
>>         It seems that there are 3 more filemarks on this tape (if I
>> counted
>>         correctly), so then this tape has 4 files, one file for the
>>         Minicom Disk
>>         Utility, and one file for each of the Logical Units.
>>
>>         I can tell you right now that the LU0 file (if that is really
>>         what it
>>         is), is 1,331,200 bytes, or exactly 1,300 Mb (if I did the math
>>         right).
>>         The other 2 files I need to study more deeply to tell for sure,
>>         as they
>>         span the tape tracks, and are more complicated for me to assemble.
>>
>>         Would it be best to just work with those as files, or do they
>>         need to be
>>         kept in their original "Kennedy" block formation, or another block
>>         formation or format?
>>
>>         Bruce, it is my goal to restore these tapes, and get a machine
>>         to run
>>         again as close as possible to the way it would have when these
>>         backups
>>         were made.  With your ability to run the Minicom file, it gives
>>         me great
>>         hope that this is possible.
>>
>>         What would be my next steps to get myself working on a system
>>         that has
>>         the capability of doing this?  I'm open to whether that is SimH,
>>         reNOVAte, or other.
>>
>>         Thank you again, Bruce, this is very exciting news!
>>
>>         -AJ
>>
>>
>>
>>
>>
>>         On Wed, Nov 18, 2015 at 1:42 AM, Bruce Ray <Bruce at wild-hare.com
>>         <mailto:Bruce at wild-hare.com>
>>         <mailto:Bruce at wild-hare.com <mailto:Bruce at wild-hare.com>>> wrote:
>>
>>              G'day AJ -
>>
>>              Briefly...
>>
>>              The tape contains a disk/tape backup/restore utility that is
>>              somewhat representative of those used with Point 4, and other
>>              3rd-party DG lookalike systems. It is a stand-alone utility
>>         that is
>>              bootable if it exists as the first record of the first file
>>         of a mag
>>              tape or cartridge.
>>
>>              The usual procedure is to bootstrap the tape using the Nova
>> APL
>>              function (or just toggling in simple 2-instruction
>> 'fat-finger'
>>              program).  Once the program is read into memory, it starts
>>         execution
>>              and displays its introductory message.  At this point another
>>              tape/cartridge may be loaded onto the tape drive for backup
>> or
>>              restore purposes.
>>
>>              I used our reNOVAte software for doing my investigations
>>         rather than
>>              SimH due to convenience, and was able to run the program and
>>              exercise its various functions. (Screen shots are attached.)
>>
>>              This particular utility is very specific regarding the type
>>         of disk
>>              drive and IRIS logical units it supports.
>>
>>              The utility assumes two devices exist: a tape controller
>> using
>>              device code <022> and a disk controller using device code
>>         <027>. The
>>              tape controller may or may not perform QIC to DG-style file
>>         handling
>>              emulation since the original tape is not available to me.
>>              The disk controller appears to use the standard DG "Zebra"
>>              controller (Model 6060/6061/6067) programming model.
>>         However, it
>>              assumes a non-standard disk geometry of 16 cylinders, 5
>>         heads, and
>>              32 sectors.
>>
>>              The tape file itself needs to be created in the SimH tape
>>         if it is
>>              to be used with the default SimH tape driver. The QIC
>>         format may
>>              exist as a single large data record of 16,384 bytes, or of
>>         multiple
>>              512-byte records followed by a file mark. (I can not tell its
>>              original format given only the .bin file to work with.)
>>
>>              The utility also makes assumptions about tape read timing
>>         and CPU
>>              instruction execution speed. Horrible programming
>>         technique, but
>>              unfortunately not uncommon practice.  Any such timing
>>         dependencies
>>              must be found and compensated for in the device driver or
>>              instruction emulation.
>>
>>              Since there is no disk backup tape to load onto the disk, I
>>         used
>>              dummy disk data for testing the disk-to-tape and tape-to-disk
>>              functions.  Real backup tape(s) would obviously be needed
>>         to restore
>>              the original system.
>>
>>
>>              Bruce
>>
>>
>>
>>              On 11/14/2015 3:35 PM, Microtech Dart wrote:
>>
>>                  Thank you, Dell, and Sandy Strain, both of your
>>         responses were
>>                  EXTREMELY
>>                  helpful to me, and these all worked!
>>
>>                  Do either of you have any additional thoughts about how
>>         I could make
>>                  what I believe to be a bootable file (extracted from a
>>                  Microtech/Point4
>>                  QIC tape) into a bootable device for the Nova?
>>
>>                  I'll start with the Minicom Disk To Tape Utility:
>>
>>
>> http://microtechm1.blogspot.com/2015/09/minicom-disk-to-tape-copy-utility.html
>>
>>                  I've attached a .zip of the binary file that I
>>         extracted from
>>                  this tape
>>                  for reference.  It's very small, so I zipped it up only
>>         so that the
>>                  emailing process didn't interfere with or reject it.
>>
>>                  Thanks, all!
>>
>>                  -AJ
>>
>>                  On Sat, Nov 14, 2015 at 7:23 AM, Dell Setzer
>>         <dsetzer at panix.com <mailto:dsetzer at panix.com>
>>                  <mailto:dsetzer at panix.com <mailto:dsetzer at panix.com>>
>>                  <mailto:dsetzer at panix.com <mailto:dsetzer at panix.com>
>>         <mailto:dsetzer at panix.com <mailto:dsetzer at panix.com>>>> wrote:
>>
>>                       It's actually pretty easy. After booting RDOS,
>>         press ^E to
>>                  return to
>>                       the sim> prompt. Then, attach a host file to the
>>         MTA0 unit.
>>                  If you
>>                       give a host filename that doesn't yet exist, SIMH
>> will
>>                  create an
>>                       empty tape file and attach it to MTA0:
>>
>>                       sim> attach mta0 testtape.tap
>>                       MTA: creating new file
>>                       sim>
>>
>>                       Then, give the simh G command to return to RDOS
>>         and init/f
>>                  the MT0
>>                       tape unit. Note that at the sim> prompt, the unit
>>         is called
>>                  "MTA0"
>>                       (or MTA1, MTA2, etc), while in RDOS the unit is
>> called
>>                  "MT0" (or
>>                       MT1, MT2, etc):
>>
>>                       sim> g
>>                       <presss return to get the RDOS prompt again>
>>                       R
>>                       init/f mt0
>>                       CONFIRM? <press Y to confirm>
>>                       R
>>
>>                       Now you can dump or copy files to the MT0 device:
>>                       dump/v mt0:0 -.sr
>>         LITMACS.SR <http://LITMACS.SR> <http://LITMACS.SR>
>>         <http://LITMACS.SR>
>>         OSID.SR <http://OSID.SR> <http://OSID.SR> <http://OSID.SR>
>>         NSID.SR <http://NSID.SR> <http://NSID.SR> <http://NSID.SR>
>>         PARS.SR <http://PARS.SR> <http://PARS.SR> <http://PARS.SR>
>>         ALMSPD.SR <http://ALMSPD.SR> <http://ALMSPD.SR> <http://ALMSPD.SR
>> >
>>                          <etc.>
>>                       R
>>                       dump/v mt0:1 -.sv
>>         BURST.SV <http://BURST.SV> <http://BURST.SV> <http://BURST.SV>
>>         INITIALIZE.SV <http://INITIALIZE.SV> <http://INITIALIZE.SV>
>>         <http://INITIALIZE.SV>
>>         SEDIT.SV <http://SEDIT.SV> <http://SEDIT.SV> <http://SEDIT.SV>
>>         MACXR.SV <http://MACXR.SV> <http://MACXR.SV> <http://MACXR.SV>
>>         EDIT.SV <http://EDIT.SV> <http://EDIT.SV> <http://EDIT.SV>
>>                          <etc.>
>>                       R
>>                       release mt0
>>                       R
>>
>>                       After releaseing the tape, press ^E again to get
>>         to the
>>                  sim> prompt
>>                       and detach the tape file:
>>                       ^E
>>                       sim> detach mta0
>>                       sim>
>>                       Now you can inspect the testtape.tap tape image.
>>
>>                       Attaching an existing tape file is similar, except
>>         that at
>>                  the RDOS
>>                       prompt you'd do INIT rather than INIT/F:
>>
>>                       sim> attach mta0 testtape.tap
>>                       sim> g
>>                       R
>>                       init mt0
>>                       R
>>                       load/n mt0:0
>>         LITMACS.SR <http://LITMACS.SR> <http://LITMACS.SR>
>>         <http://LITMACS.SR>
>>                  10/20/83
>>         OSID.SR <http://OSID.SR> <http://OSID.SR> <http://OSID.SR>
>>                   01/10/84
>>         NSID.SR <http://NSID.SR> <http://NSID.SR> <http://NSID.SR>
>>                   10/20/83
>>         PARS.SR <http://PARS.SR> <http://PARS.SR> <http://PARS.SR>
>>                   01/31/85
>>                          <etc>
>>                       R
>>                       load/n mt0:1
>>         BURST.SV <http://BURST.SV> <http://BURST.SV> <http://BURST.SV>
>>                      05/09/85
>>         INITIALIZE.SV <http://INITIALIZE.SV> <http://INITIALIZE.SV>
>>         <http://INITIALIZE.SV>
>>                      05/02/85
>>         SEDIT.SV <http://SEDIT.SV> <http://SEDIT.SV> <http://SEDIT.SV>
>>                      05/02/85
>>                          <etc>
>>                       R
>>                       release mt0
>>                       R
>>
>>                       Hope this helps,
>>                       ...dell
>>
>>                       On Sat, 14 Nov 2015, Microtech Dart wrote:
>>
>>                           Hi, I am completely new here, although I
>>         recognize the
>>                  names of
>>                           several who
>>                           post here.
>>
>>                           I am trying to resurrect an extinct Microtech
>>         machine
>>                  from 1982,
>>                           which
>>                           likely used the Point 4 processor, and the
>>         SimH DG Nova
>>                           simulator *should*
>>                           be compatible with the Point 4.
>>
>>                           I'm running the NOVA simulator now, with:
>>
>>                           NOVA simulator V4.0-0 Beta        git commit
>>         id: 3be5125d
>>                           sim> ATTACH DKP0 *rdos_d31.dsk*
>>                           sim> set tti dasher
>>                           sim> boot DKP0
>>
>>                           I'm teaching myself RDOS now with the
>>                           RDOS_Command_Line_Interpreter Manual.
>>
>>
>>         <
>> http://www.mirrorservice.org/sites/www.bitsavers.org/pdf/dg/software/rdos/093-000109-01_RDOS_Command_Line_Interpreter.pdf
>> >
>>
>>                           Would anybody here be able to suggest some
>>         methods by
>>                  which I could
>>                           *create* a magnetic tape device on this SimH
>> Nova
>>                  simulator, and
>>                           how I
>>                           might write some files to that?
>>
>>                           I think that would be an excellent experiment
>>         for me to
>>                           attempt.  Then I
>>                           can inspect the binary file in a hex editor,
>>         and see
>>                  what it
>>                           looks like,
>>                           then compare to the binaries I've pulled off my
>>                  Microtech/Point
>>                           4 tapes.
>>
>>                           --
>>
>>                           Thanks,
>>                           -AJ
>>         http://MicrotechM1.blogspot.com
>>
>>
>>
>>
>>                  --
>>
>>                  Thanks,
>>                  -AJ
>>         http://MicrotechM1.blogspot.com
>>
>>
>>                  _______________________________________________
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>>
>>              _______________________________________________
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>>
>>
>>
>>
>>         --
>>
>>         Thanks,
>>         -AJ
>>         http://MicrotechM1.blogspot.com
>>
>>
>>         _______________________________________________
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>>
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>>
>>
>>
>>
>> --
>>
>> Thanks,
>> -AJ
>> http://MicrotechM1.blogspot.com
>>
>


-- 

Thanks,
-AJ
http://MicrotechM1.blogspot.com
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