7 Sep
2011
7 Sep
'11
8:14 a.m.
someone just pointed this out to me
http://www.archive.org/details/2011-cdc-disk-archaeology-fenton
Chris Fenton's report on recovering data from an 80mb disk pack.
7 Sep
7 Sep
1:08 p.m.
At 10:14 AM 9/7/2011, Al Kossow wrote:
someone just pointed this out to me
http://www.archive.org/details/2011-cdc-disk-archaeology-fenton
Chris Fenton's report on recovering data from an 80mb disk pack.
Well, he recovered oversampled waveforms of what was on the disk pack...
It did not say he recovered files, right?
- John
2:34 p.m.
On 9/7/11 1:08 PM, John Foust wrote:
At 10:14 AM 9/7/2011, Al Kossow wrote:
This is what I posted on
http://blog.archive.org/2011/09/03/hard-drive-archaeology-and-hackerspaces
--
I wish Chris would have emailed me about the service manual. I have others which were for
earlier drives.
It will be interesting to see how far he gets interpreting the sector format. Hopefully he
can leave the
setup in place until he verifies that the comparator that he built worked correctly by
decoding the
sector data. The description of the circuit that CDC used is quite a bit more complicated
than what he used.
Also, Jason, I have several 80 mb CDC packs, and I can get a correct picture for you.
The one you show is an earlier 200 mb version with 12 instead of 5 disk platters.
someone just pointed this out to me
http://www.archive.org/details/2011-cdc-disk-archaeology-fenton
Chris Fenton's report on recovering data from an 80mb disk pack.
Well, he recovered oversampled waveforms of what was on the disk pack...
It did not say he recovered files, right?
8 Sep
8 Sep
2:17 a.m.
On Wed, 7 Sep 2011, John Foust wrote:
At 10:14 AM 9/7/2011, Al Kossow wrote:
Right, that's how I read that, too. And it was a fairly complicate way of
getting the raw data off the disk pack. It'd probably have been *much*
easier repairing the drives (that surely weren't in so bad shape) and
building a small interface to attach them to whatever system he was using.
Christian
someone just pointed this out to me
http://www.archive.org/details/2011-cdc-disk-archaeology-fenton
Chris Fenton's report on recovering data from an 80mb disk pack.
Well, he recovered oversampled waveforms of what was on the disk pack...
It did not say he recovered files, right?
7:34 a.m.
On 9/8/11 2:17 AM, Christian Corti wrote:
attach them to whatever system he was using.
All he had was a pack from the front end (Eclipse ?) of a Cray.
I don't think he even knows what disk controller it was connected to
although I would think that Cray would have used one from DG.
I've not seen any postings about this on Controlfreaks. I should post
something over there to see what people know.
8:27 a.m.
On Thu, 8 Sep 2011, Al Kossow wrote:
On 9/8/11 2:17 AM, Christian Corti wrote:
But that's a standard SMD drive, isn't it? So it should be rather simple
to make a minimalistic SMD interface for his analyzer system (his PC) just
to control the positioning system and to read the sector data.
I could use such an interface because I have three Fujitsu drives from a
Nixdorf system that I want to read out. The controller format is unknown
(as everything from a Nixdorf...), and I haven't had luck with my SUN VME
controllers (I've programmed them directly). But time... a very rare good
today.
Christian
attach them to whatever system he was using.
All he had was a pack from the front end (Eclipse ?) of a Cray.
I don't think he even knows what disk controller it was connected to
although I would think that Cray would have used one from DG.
8:40 a.m.
On 9/8/11 7:34 AM, Al Kossow wrote:
On 9/8/11 2:17 AM, Christian Corti wrote:
message from Chris..
Anyway, I did an actual write-up for my website here:
http://chrisfenton.com/cray-1-digital-archeology/
Some guy from Norway downloaded my dataset and actually managed to figure out the sector
encoding (including the header and checksum scheme!), and he wrote a script (that is up on
my site) that can
extract and verify the raw sectors.
The disk uses 32 sectors/track, with 512 bytes/sector. My thought is that the disk either
belonged to some sort of data general eclipse, or to a Cray IOS. It looks like it was used
for some kind of
diagnostics/testing for 1/s and 1/m machines.
I should hopefully be able to post a dump of the actual extracted sectors to my website
later tonight.
-Chris
attach them to whatever system he was using.
All he had was a pack from the front end (Eclipse ?) of a Cray.
I don't think he even knows what disk controller it was connected to
although I would think that Cray would have used one from DG.
I've not seen any postings about this on Controlfreaks. I should post
something over there to see what people know.
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aek＠bitsavers.org -
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jfoust＠threedee.com