On 1/5/2017 9:49 AM, Pete Lancashire wrote:
I would clean all the heads, and the surface with a soft cloth and give it a
try.
A place I worked, a "soft dry cloth" unless it came out of a package
made by Texwipe or their competitors was known as "sand paper", if you
were caught using such you
Kimwipes ! That's the brand and products I could not remember. Just one
thing to add, there are many different types/variations, so be careful.
On Jan 5, 2017 7:15 AM, "Paul Koning" wrote:
> On Thu, Jan 5, 2017 at 3:44 AM, Klemens Krause <
> kra...@informatik.uni-stuttgart.de> wrote:
>
> > ...
>
>>I would clean all the heads, and the surface with a soft cloth and give it a
>>try.
A place I worked, a "soft dry cloth" unless it came out of a package
made by Texwipe or their competitors was known as "sand paper", if you
were caught using such you were fired on the spot and escorted out the
On Thu, Jan 5, 2017 at 3:44 AM, Klemens Krause <
kra...@informatik.uni-stuttgart.de> wrote:
> ...
> Cleaning the originally coated drum? I'm not sure how to do this.
> We clean our RK05 disks in a very robust way: with cheap burning
> spirit and paper towels. ...
> The LGP-30 drum is much more sin
On Thu, Jan 5, 2017 at 3:44 AM, Klemens Krause <
kra...@informatik.uni-stuttgart.de> wrote:
>
>>
>> http://www.radar58.com/temp/drum.jpg
>> http://www.radar58.com/temp/drum2.jpg
>>
>
> From the fotos your drum looks better than our working one, with
> the exception of the large engraving on the ri
On Wed, 4 Jan 2017, Cory Heisterkamp wrote:
On Jan 4, 2017, at 1:02 PM, allison wrote:
On 1/4/17 1:06 PM, Jon Elson wrote:
Previous messages suggested the LGP-30 drum was plated with nickel.
Nope. I ever wrote about iron oxide.
I'm far from an expert, but it certainly looks like an ox
On Wed, 4 Jan 2017, Cory Heisterkamp wrote:
I'm far from an expert, but it certainly looks like an oxide coating to
me. I'm reminded of the folklore when IBM was developing the RAMAC and
Yes, it is ferric oxide.
http://www.radar58.com/temp/drum.jpg
http://www.radar58.com/temp/drum2.jpg
Hmm,
On 01/04/2017 09:56 PM, Jon Elson wrote:
> On 01/04/2017 05:24 PM, Cory Heisterkamp wrote:
>>
>> I'm far from an expert, but it certainly looks like an oxide coating
>> to me. I'm reminded of the folklore when IBM was developing the RAMAC
>> and finally had success with a magnetic paint mixed up ou
On 01/04/2017 03:50 PM, Paul Koning wrote:
>> On Jan 4, 2017, at 2:48 PM, Kyle Owen wrote:
>>
>> On Wed, Jan 4, 2017 at 12:06 PM, Jon Elson wrote:
>>> Previous messages suggested the LGP-30 drum was plated with nickel. If
>>> there are amateur astronomers with a vacuum evaporator, it might be
>>>
On 01/04/2017 05:24 PM, Cory Heisterkamp wrote:
I'm far from an expert, but it certainly looks like an oxide coating to me. I'm
reminded of the folklore when IBM was developing the RAMAC and finally had
success with a magnetic paint mixed up outside of house. In that case it was
easy to apply
On 1/4/2017 7:56 AM, allison wrote:
Sperm oil was a high quality wax/lubricant. Its low viscosity and high
resistance to oxidation
were its high points. Its likely use was as a plasticize the binder
and surface.
As far as I know it is illegal to purchase or transfer now. Not to
possess. I
On Jan 4, 2017, at 1:02 PM, allison wrote:
> On 1/4/17 1:06 PM, Jon Elson wrote:
>> On 01/04/2017 09:03 AM, Klemens Krause wrote:
>>>
>>>
We both have analog recordings (from digitizing scopes) and logic analyzer
dumps. So concerning the LGP-30, all relevant information about the dru
On 1/4/17 1:06 PM, Jon Elson wrote:
On 01/04/2017 09:03 AM, Klemens Krause wrote:
We both have analog recordings (from digitizing scopes) and logic
analyzer dumps. So concerning the LGP-30, all relevant information
about the drum has been saved :-)
We have a second LGP-30 drum in our mus
On Wed, Jan 4, 2017 at 12:30 PM, Chuck Guzis wrote:
> On 01/04/2017 11:48 AM, Kyle Owen wrote:
>
> > Will the desired thickness be enough with sputtering or evaporation?
> > For modern hard drives, sure, but my gut instinct is that you'd want
> > a thicker coating on the drum. I'd suggest sputter
> On Jan 4, 2017, at 2:48 PM, Kyle Owen wrote:
>
> On Wed, Jan 4, 2017 at 12:06 PM, Jon Elson wrote:
>>
>> Previous messages suggested the LGP-30 drum was plated with nickel. If
>> there are amateur astronomers with a vacuum evaporator, it might be
>> possible to get them to adjust their setup
On 01/04/2017 11:48 AM, Kyle Owen wrote:
> Will the desired thickness be enough with sputtering or evaporation?
> For modern hard drives, sure, but my gut instinct is that you'd want
> a thicker coating on the drum. I'd suggest sputtering over
> evaporation since it will probably adhere to the sur
On Wed, Jan 4, 2017 at 12:06 PM, Jon Elson wrote:
>
> Previous messages suggested the LGP-30 drum was plated with nickel. If
> there are amateur astronomers with a vacuum evaporator, it might be
> possible to get them to adjust their setup slightly to vacuum evaporate
> nickel on your drum, after
> On Jan 4, 2017, at 1:06 PM, Jon Elson wrote:
>
>> ...
>>
> Previous messages suggested the LGP-30 drum was plated with nickel. If there
> are amateur astronomers with a vacuum evaporator, it might be possible to get
> them to adjust their setup slightly to vacuum evaporate nickel on your dr
On 01/04/2017 09:03 AM, Klemens Krause wrote:
We both have analog recordings (from digitizing scopes)
and logic analyzer dumps. So concerning the LGP-30, all
relevant information about the drum has been saved :-)
We have a second LGP-30 drum in our museum. It is damaged
by water.
(large
On 01/04/2017 06:05 AM, Christian Corti wrote:
The LGP-30 is similar, but the timing and long tracks
(i.e. main memory) are not recirculating. Hence the reason
why a word is limited to 31 bits, although the sector
holds 32 bits. The last bit must be zero to reset the read
circuitry for the n
On Wed, 4 Jan 2017, Al Kossow wrote:
On 1/4/17 7:03 AM, Klemens Krause wrote:
We have a second LGP-30 drum in our museum. It is damaged by water.
...
In doing some disk research recently, I came across a footnote for a rather
unlikely
place to find information on magnetic coatings, whi
On 1/4/17 10:19 AM, Al Kossow wrote:
On 1/4/17 7:03 AM, Klemens Krause wrote:
We have a second LGP-30 drum in our museum. It is damaged by water.
(large rusted areas, probably from water between heads and drum).
I'm dreaming to wash the brown oxide coating off with a solvent like
acetone, poli
On 1/4/17 7:03 AM, Klemens Krause wrote:
> We have a second LGP-30 drum in our museum. It is damaged by water.
> (large rusted areas, probably from water between heads and drum).
> I'm dreaming to wash the brown oxide coating off with a solvent like
> acetone, polish the drum and repaint it.
> A
On Wed, 4 Jan 2017, Christian Corti wrote:
On Tue, 3 Jan 2017, Al Kossow wrote:
There are running LGP-30s. Should be short work with a digital oscillosope
We both have analog recordings (from digitizing scopes) and logic analyzer
dumps. So concerning the LGP-30, all relevant information
On Tue, 3 Jan 2017, Jon Elson wrote:
So, does the LGP-30 have permanent storage on the drum, or is it erased by a
magnet at every revolution?
Yes, the three timing tracks, and the upper half of the instruction
counter(!). The upper half containts the number of the following
sector and is used
On Tue, 3 Jan 2017, Al Kossow wrote:
There are running LGP-30s. Should be short work with a digital
oscillosope to capture the flux changes. Hopefully, someone has done
this already.
Of course, we did this initially in 1999 when we got our first LGP-30, and
a couple of times later on. The las
On Tue, 3 Jan 2017, Paul Koning wrote:
The key questions for reconstructing such a device is what the
modulation scheme is, and the pulse pattern. There might be marker
pulses for sector start, for example, or that might just be derived from
a counter in the controller.
It's in the maintenan
On 01/03/2017 01:47 PM, Brian L. Stuart wrote:
On Tue, 1/3/17, Cory Heisterkamp wrote:
What I’m wondering is if anyone is familiar with the setup/adjustment
procedure for getting the heads set correctly. There *might* be a couple of
unused tracks I can relocate heads to, but my thought is that
On 1/3/17 5:42 PM, Al Kossow wrote:
>
> I think Paul Pierce's machine is at LCM now.
They have his LGP-30
On 1/3/17 5:42 PM, Al Kossow wrote:
>
> Someone should do the same for the surviving G-15s as well. I think Paul
> Pierce's machine is at LCM now.
>
turns out we have it
http://www.computerhistory.org/collections/catalog/102728118
On 1/3/17 5:22 PM, Paul Koning wrote:
> The key questions for reconstructing such a device is what the modulation
> scheme is, and the pulse pattern.
There are running LGP-30s. Should be short work with a digital oscillosope to
capture the flux changes.
Hopefully, someone has done this alread
> On Jan 3, 2017, at 6:07 PM, Chuck Guzis wrote:
>
> On 01/03/2017 01:42 PM, Mark Linimon wrote:
>
>> Very ambitious. IIRC for the G-15 there is/are (one? two?) timing
>> track(s) which were written at the factory. Of course whatever that
>> machine was, has not survived. I remember reading
On Jan 3, 2017, at 2:22 PM, Klemens Krause wrote:
> On Tue, 3 Jan 2017, Cory Heisterkamp wrote:
>>
>>
>> What I’m wondering is if anyone is familiar with the setup/adjustment
>> procedure for getting the heads set correctly. There *might* be a couple of
> We relocated some of the heads on
On 01/03/2017 01:42 PM, Mark Linimon wrote:
> Very ambitious. IIRC for the G-15 there is/are (one? two?) timing
> track(s) which were written at the factory. Of course whatever that
> machine was, has not survived. I remember reading that if you lost
> that timing track, your machine was toast.
On 01/03/2017 01:19 PM, Paul Koning wrote:
> Metal alloy plating seems common in fixed head disks also, at least
> in the ones from DEC I have seen. Making a new drum sounds like a
> great class project for an ambitious machine shop student.
Modern CNC gear and carbide bits should make this pret
On Tue, Jan 03, 2017 at 04:19:01PM -0500, Paul Koning wrote:
> Making a new drum sounds like a great class project for an ambitious
> machine shop student.
Very ambitious. IIRC for the G-15 there is/are (one? two?) timing track(s)
which were written at the factory. Of course whatever that machin
> On Jan 3, 2017, at 4:15 PM, Chuck Guzis wrote:
>
> On 01/03/2017 12:57 PM, Cory Heisterkamp wrote:
>
>> Once I can make sense of the timing tracks, I think I'll proceed with
>> this. Not sure how I feel about using a micro-based solution though.
>> Just seems wrong : ) -C
>
>
> If enough
On 01/03/2017 12:57 PM, Cory Heisterkamp wrote:
> Once I can make sense of the timing tracks, I think I'll proceed with
> this. Not sure how I feel about using a micro-based solution though.
> Just seems wrong : ) -C
If enough working heads can be found, the drum probably can be
remanufactured
On Tue, Jan 3, 2017 at 1:47 PM, Brian L. Stuart
wrote:
> On Tue, 1/3/17, Cory Heisterkamp wrote:
> > What I’m wondering is if anyone is familiar with the setup/adjustment
> > procedure for getting the heads set correctly. There *might* be a couple
> of
> > unused tracks I can relocate heads to,
On Tue, 3 Jan 2017, Cory Heisterkamp wrote:
What I’m wondering is if anyone is familiar with the setup/adjustment
procedure for getting the heads set correctly. There *might* be a couple of
We relocated some of the heads on our second LGP-30. This is not
difficult. We put 3 or 4 layers of 3 mi
On Tue, 1/3/17, Cory Heisterkamp wrote:
> What I’m wondering is if anyone is familiar with the setup/adjustment
> procedure for getting the heads set correctly. There *might* be a couple of
> unused tracks I can relocate heads to, but my thought is that if half a
> dozen heads were already in cont
In a message dated 1/3/2017 11:11:54 A.M. US Mountain Standard Time,
el...@pico-systems.com writes:
On 01/03/2017 10:58 AM, Cory Heisterkamp wrote:
> While waiting for the machine, I decided to investigate the stuck drum.
> This unit has 71 read/write heads plus what appears to be an induct
On 01/03/2017 10:58 AM, Cory Heisterkamp wrote:
While waiting for the machine, I decided to investigate the stuck drum.
This unit has 71 read/write heads plus what appears to be an inductive
pickup for the system clock. Upon closer examination I discovered multiple
heads in contact with the drum
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