26 Jun
2007
26 Jun
'07
7:08 p.m.
Hello cctalkers,
I'm trying to help someone recover data from an MFM drive in an old Pinnacle 1a system
that had MirageOS installed. The system hasn't been booted in years and no longer
boots to the hard disk. The drive spins up and sounds okay. We've tried to track
down a copy of the MirageOS boot diskettes for the Pinnacle 1a system but haven't
found any after looking for months.
It's time to come up with a "Plan B". Does anyone have a suggestion about
how to read the "raw" data from the MFM hard disk? I was thinking about putting
in into an older PC based system with an MFM controller and using some utilities to dump
sectors to files that I could convert into something readable/usable. I haven't done
this before so I'm hoping someone smarter has a 'cunning plan' of how to do
this. I'm a programmer and don't mind write some utilities to pick apart the data
after it's off the hard drive.
Any ideas are appreciated.
Thanks,
david.
daviderhart at oldzonian.com
daviderhart at sageandstride.org
http://www.sageandstride.org
27 Jun
27 Jun
2:45 a.m.
On Tue, 2007-06-26 at 19:08 -0400, David W. Erhart wrote:
Hello cctalkers,
I'm trying to help someone recover data from an MFM drive in an old Pinnacle 1a
system that had MirageOS installed. The system hasn't been booted in years and no
longer boots to the hard disk. The drive spins up and sounds okay. We've tried to
track down a copy of the MirageOS boot diskettes for the Pinnacle 1a system but
haven't found any after looking for months.
It's time to come up with a "Plan B". Does anyone have a suggestion about
how to read the "raw" data from the MFM hard disk? I was thinking about putting
in into an older PC based system with an MFM controller and using some utilities to dump
sectors to files that I could convert into something readable/usable. I haven't done
this before so I'm hoping someone smarter has a 'cunning plan' of how to do
this. I'm a programmer and don't mind write some utilities to pick apart the data
after it's off the hard drive.
Any ideas are appreciated.
Unfortunately MFM controllers tend not to be interchangeable. For the
most part, you can't swap a drive onto a different controller and expect
it to read and write properly. I suppose if you're just reading it, it
can't hurt to try. Doubtless someone will point out why it's a bad idea
to do that though.
Gordon
3:28 a.m.
On 26 Jun 2007 at 19:08, David W. Erhart wrote:
It's time to come up with a "Plan B".
Does anyone have a suggestion
about how to read the "raw" data from the MFM hard disk? I was
thinking about putting in into an older PC based system with an MFM
controller and using some utilities to dump sectors to files that I
could convert into something readable/usable. I haven't done this
before so I'm hoping someone smarter has a 'cunning plan' of how to do
this. I'm a programmer and don't mind write some utilities to pick
apart the data after it's off the hard drive.
David, I can only vaguely remember seeing Pinnacles when my firm was
looking for micro alternatives to another VAX and 68K systems were on
the list We eventually ended up with a Plexus and were very unhappy
with the performance. Water under the bridge.
I think the chances of a PC MFM controller making sense out of your
hard disk are remote at best. Address marks, CRC polynomials and a
host of other variables generally makes for lots of incompatibility
between controllers. But it might give you some good information.
By hooking the drive up to PC and then using INT 13 services to probe
sectors at random, you should be able to determine if the drive will
at least seek. You'll get "sector not found" or "seek error"
status
back, but you'll be able to observe the drive and see if it's
working.
You can also try another MFM drive on the Pinnacle to see if it's at
least accessed by the controller.
What's the controller chip on the Pinnacle for the hard disk?
Do you have any documentation on the system?
Cheers,
Chuck
6:19 a.m.
What make is the drive?
Do the heads un-load?
If it's a Micropolis there is a know issue that is affects the drive over
the course of time which was pointed out to me and the fix worked a treat!
Have a look on the alias archive for "sticky bumpers".
Ta,
Andy.
On 27/06/07, Chuck Guzis <cclist at sydex.com> wrote:
On 26 Jun 2007 at 19:08, David W. Erhart wrote:
It's time to come up with a "Plan
B". Does anyone have a suggestion
about how to read the "raw" data from the MFM hard disk? I was
thinking about putting in into an older PC based system with an MFM
controller and using some utilities to dump sectors to files that I
could convert into something readable/usable. I haven't done this
before so I'm hoping someone smarter has a 'cunning plan' of how to do
this. I'm a programmer and don't mind write some utilities to pick
apart the data after it's off the hard drive.
David, I can only vaguely remember seeing Pinnacles when my firm was
looking for micro alternatives to another VAX and 68K systems were on
the list We eventually ended up with a Plexus and were very unhappy
with the performance. Water under the bridge.
I think the chances of a PC MFM controller making sense out of your
hard disk are remote at best. Address marks, CRC polynomials and a
host of other variables generally makes for lots of incompatibility
between controllers. But it might give you some good information.
By hooking the drive up to PC and then using INT 13 services to probe
sectors at random, you should be able to determine if the drive will
at least seek. You'll get "sector not found" or "seek error"
status
back, but you'll be able to observe the drive and see if it's
working.
You can also try another MFM drive on the Pinnacle to see if it's at
least accessed by the controller.
What's the controller chip on the Pinnacle for the hard disk?
Do you have any documentation on the system?
Cheers,
Chuck
7:54 a.m.
--- Andy Piercy <andy.piercy at gmail.com> wrote:
What make is the drive?
Do the heads un-load?
Have a look on the alias archive for "sticky
bumpers".
I agree - the Micropolis drives are very prone to
that. It'll spin, but the heads never load and it
won't seek because they're glued to their stop with
the rubber bumper pad.
Also, as stupid as it sounds, are you running the
machine in it's normal physical orientation, or are
you running it on it's side, on a workbench?
Sometimes, if the drive is really well used, if the
drive was formatted and working whilst horizontal, it
won't work properly when turned on it's side.
Combination of the normal effects of gravity on the
device, and well worn stepper motors cause the heads
to not line up with the tracks. Just a thought.
-Ian
6212
days inactive
6213
days old
4 comments
5 participants
participants (5)
-
andy.piercy＠gmail.com -
cclist＠sydex.com -
daviderhart＠oldzonian.com -
gordon＠gjcp.net -
ian_primus＠yahoo.com