Re: Cleaning RK05 packs (Was: LGP-30 Memory Drum Update)

>>Ah, oh How should that get between the heads and the platter? If it can happen it will. It did. I had saved up three or four cartridges for future repair. I was told such work should be done by (someone not so expensive) so off they went to one of the manufacturing repair techs. I was busy

Re: Cleaning RK05 packs (Was: LGP-30 Memory Drum Update)

On 01/05/2017 02:22 PM, Noel Chiappa wrote: > From: Klemens Krause > We clean our RK05 disks in a very robust way: with cheap burning spirit > and paper towels. ... We rubbed away thick black traces from occasional > head crashes and we never removed the oxide coating with this

Re: Cleaning RK05 packs (Was: LGP-30 Memory Drum Update)

Another thing to watch out for is the two halves of some if not all were screwed together with self tapping screws. When you take them apart bit of plastic may come out of the holes or fall off the insides of the screw threads. That plastic if gets between the platter and head will not be to

Re: Drum Computers (Was Cleaning things (was Cleaning RK05 packs (Was: LGP-30 Memory Drum Update)))

On 01/07/2017 07:01 AM, Al Kossow wrote: > On 1/7/17 3:06 AM, jim stephens wrote: > >> They did make a tape drive of some sort > > They made several generations, what I've found on their cartridge > tape drives is under 3M on bitsavers. All use variations of their > trade secret or what

Re: Drum Computers (Was Cleaning things (was Cleaning RK05 packs (Was: LGP-30 Memory Drum Update)))

On 1/7/17 3:06 AM, jim stephens wrote: They did make a tape drive of some sort They made several generations, what I've found on their cartridge tape drives is under 3M on bitsavers. All use variations of their trade secret or what eventually became QIC standard tape formats. The 1/4"

Re: Drum Computers (Was Cleaning things (was Cleaning RK05 packs (Was: LGP-30 Memory Drum Update)))

On January 7, 2017 5:06:32 AM CST, jim stephens wrote: > > >On 1/6/2017 6:46 PM, Rick Bensene wrote: >> Today, there seems to be no record that 3M ever was in the computer >business. But...it was. >They inflicted the write only media on the world that became QIC. So >they

Re: Drum Computers (Was Cleaning things (was Cleaning RK05 packs (Was: LGP-30 Memory Drum Update)))

On 1/6/2017 6:46 PM, Rick Bensene wrote: Today, there seems to be no record that 3M ever was in the computer business. But...it was. They inflicted the write only media on the world that became QIC. So they were in the biz long enough to do that. Media never intended to be recorded at the

RE: Cleaning RK05 packs (Was: LGP-30 Memory Drum Update)

Here is the exact reference for the clean room wipes: Berkshire DURX 670 Item #: DR670.0404.10 4"x4" (10cm x10 cm) Non-woven Polyester/Cellulose And isopropyl alcohol we use is 99.9%, not just 99 as I said. Marc -Original Message- We use 6"x6" clean room rated wipes (I think they were

RE: Drum Computers (Was Cleaning things (was Cleaning RK05 packs (Was: LGP-30 Memory Drum Update)))

Allison wrote; >I envy the chance to restore a LGP-30 or for that fact play with one. >Many of the things I remember >mid sixties on are now gone or were rare then. Like small desk sized drum >computers using transistors or first generation IC (RTL and RDTL). I so regret not having rescued

Re: Cleaning things (was Cleaning RK05 packs (Was: LGP-30 Memory Drum Update))

On 01/06/2017 07:32 AM, David Bridgham wrote: > On 01/05/2017 08:13 PM, allison wrote: > >> Lots of ifs, mights, and maybes. My knowledge is from actually owning >> and maintaining a Cessna since 1979 and so far that has not been an issue. > Yup, that's just how the discussion in the aircraft

Re: Cleaning RK05 packs (Was: LGP-30 Memory Drum Update)

>>The latter 91% is safe for many uses and is water clear it leaves no residue >>(however one must assure its dry after). And what type of microscope did you use to determine there is no residue ? On Thu, Jan 5, 2017 at 9:23 AM, allison wrote: > On 1/5/17 8:36 AM, E.

Re: Cleaning RK05 packs (Was: LGP-30 Memory Drum Update)

On 01/05/2017 08:13 PM, allison wrote: > Lots of ifs, mights, and maybes. My knowledge is from actually owning > and maintaining a Cessna since 1979 and so far that has not been an issue. Yup, that's just how the discussion in the aircraft community went. One group would point out that Simple

Re: Cleaning RK05 packs (Was: LGP-30 Memory Drum Update)

We use 6"x6" clean room rated wipes (I think they were either Berkshires or Kimwipes) from Grainger and 99% isopropyl alcohol from Fry's. Won't scratch, free of microscopic dust and lint, and 99% alcohol will leave no drying marks (it's typically the last rinse in IC manufacturing). May cost

Re: Cleaning RK05 packs (Was: LGP-30 Memory Drum Update)

On 01/05/2017 05:13 PM, allison wrote: >> Freon TF works well on everything. Too bad it's not available. >> >> Is it still used for aircraft electronics? > No its been obsoleted. There are many other similar but not > fluorinated hydrocarbons that are preferred and also good old soap > and

Re: Cleaning RK05 packs (Was: LGP-30 Memory Drum Update)

On 01/05/2017 11:38 AM, Pete Lancashire wrote: you could test various solvents with a Q-tip to make sure they don't cause damage. And a week later after the binder had decomposed what are you going to do ? That's why you test in a non-critical area, and then let it sit for a while to make

Re: Cleaning RK05 packs (Was: LGP-30 Memory Drum Update)

On 01/05/2017 07:15 PM, Chuck Guzis wrote: > On 01/05/2017 03:24 PM, David Bridgham wrote: > >> This question of whether Simple Green was aluminum safe came up in >> the aircraft world a few years back and the answer turned out to be >> that some ingredient in there is mildly corrosive to

Re: Cleaning RK05 packs (Was: LGP-30 Memory Drum Update)

"A pack inspector is a handy thing to have (spinle with microscope and illuminator on the rack and pinion)" Can you post a picture of this critter? Is it something we could 3D print? Thanks, Marc On Thu, Jan 5, 2017 at 6:40 AM, Al Kossow wrote: > isopropyl alcohol works.

Re: Cleaning RK05 packs (Was: LGP-30 Memory Drum Update)

On 1/5/17 12:30 PM, Al Kossow wrote: On 1/5/17 9:22 AM, j...@cimmeri.com wrote: As Allison taught me, the oxide surface on platters / drums is just a form of inactive RUST.. and therefore, unaffected by water (no, the water doesn't cause it to start rusting further). The interface between

Re: Cleaning RK05 packs (Was: LGP-30 Memory Drum Update)

On 1/5/17 10:56 AM, Mouse wrote: In the US, "rubbing alcohol" is mostly denatured ethanol (though "isopropyl$ Interesting. I don't think I've ever seen a bottle of "rubbing alcohol" that was anything but isopropanol-and-water. But I'm more Canadian than US. Many are possible in the local

Re: Cleaning RK05 packs (Was: LGP-30 Memory Drum Update)

On 1/5/17 8:36 AM, E. Groenenberg wrote: We have a similar common name for it being 'brand spiritus'. It's basically 90% - 92% alcohol, with the rest being methanol and water and it's color is blue-ish. Ed -- In the past from the local print and painting supplier "De-natured alcohol" Usually

Re: Cleaning RK05 packs (Was: LGP-30 Memory Drum Update)

>>you could test various solvents with a Q-tip to make sure they don't cause >>damage. And a week later after the binder had decomposed what are you going to do ? On Thu, Jan 5, 2017 at 9:05 AM, Jon Elson wrote: > On 01/05/2017 07:22 AM, Noel Chiappa wrote: >> >> >

Re: Cleaning RK05 packs (Was: LGP-30 Memory Drum Update)

On 01/05/2017 03:24 PM, David Bridgham wrote: > This question of whether Simple Green was aluminum safe came up in > the aircraft world a few years back and the answer turned out to be > that some ingredient in there is mildly corrosive to aluminum. Not > badly so and if you managed to flush it

Re: Cleaning RK05 packs (Was: LGP-30 Memory Drum Update)

On Thu, 5 Jan 2017 08:22:05 -0500 (EST) j...@mercury.lcs.mit.edu (Noel Chiappa) wrote: > > From: Klemens Krause > > > We clean our RK05 disks in a very robust way: with cheap > > burning spirit and paper towels. ... We rubbed away thick black > > traces from occasional head

Re: Cleaning RK05 packs (Was: LGP-30 Memory Drum Update)

On 01/05/2017 12:22 PM, j...@cimmeri.com wrote: > > It's very mild and has been aluminum safe for me (think, aluminum > wheels on cars). This question of whether Simple Green was aluminum safe came up in the aircraft world a few years back and the answer turned out to be that some ingredient in

Re: Cleaning RK05 packs (Was: LGP-30 Memory Drum Update)

On Thu, Jan 5, 2017 at 5:30 PM, Al Kossow wrote: > > > On 1/5/17 9:22 AM, j...@cimmeri.com wrote: > >> As Allison taught me, the oxide surface on platters / drums is just a form >> of inactive RUST.. and therefore, unaffected >> by water (no, the water doesn't cause it to

Re: Cleaning RK05 packs (Was: LGP-30 Memory Drum Update)

> Another thing to watch out for is the two halves of some if not all > were screwed together with self tapping screws. When you take > them apart bit of plastic may come out of the holes or fall off the > insides of the screw threads. That plastic if gets between the platter > and head will not

Re: Cleaning RK05 packs (Was: LGP-30 Memory Drum Update)

On 1/5/2017 12:30 PM, Al Kossow wrote: On 1/5/17 9:22 AM, j...@cimmeri.com wrote: As Allison taught me, the oxide surface on platters / drums is just a form of inactive RUST.. and therefore, unaffected by water (no, the water doesn't cause it to start rusting further). The interface

Re: Cleaning RK05 packs (Was: LGP-30 Memory Drum Update)

It's very mild and has been aluminum safe for me (think, aluminum wheels on cars). As Allison taught me, the oxide surface on platters / drums is just a form of inactive RUST.. and therefore, unaffected by water (no, the water doesn't cause it to start rusting further). - J. On

Re: Cleaning RK05 packs (Was: LGP-30 Memory Drum Update)

On 1/5/17 9:22 AM, j...@cimmeri.com wrote: > As Allison taught me, the oxide surface on platters / drums is just a form of > inactive RUST.. and therefore, unaffected > by water (no, the water doesn't cause it to start rusting further). > The interface between the aluminum platter and the

Re: Cleaning RK05 packs (Was: LGP-30 Memory Drum Update)

http://simplegreen.com/downloads/SDS_EN-US_SimpleGreenAllPurposeCleaner.pdf not something I would think of using on a disk surface On 1/5/17 8:59 AM, Liam Proven wrote: > On 5 January 2017 at 17:11, j...@cimmeri.com wrote: >> - apply some Simple Green to a microfiber cloth >

Re: LGP-30 Memory Drum Update

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

Re: Cleaning RK05 packs (Was: LGP-30 Memory Drum Update)

On 1/5/2017 11:59 AM, Liam Proven wrote: On 5 January 2017 at 17:11, j...@cimmeri.com wrote: - apply some Simple Green to a microfiber cloth I may be the odd one out here, but what on Earth is "Simple Green?" https://www.youtube.com/watch?v=TkZFuKHXa7w Ever heard of

Re: LGP-30 Memory Drum Update

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 < >

Re: LGP-30 Memory Drum Update

>>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

Re: Cleaning RK05 packs (Was: LGP-30 Memory Drum Update)

DEC (branded, made by Texwipe) cleaning pads contained 99% isopropyl alcohol. The most important part was being non abrasive. I would consider using Texwipe or other brands of non abrasive materials before I even though about a solvent. I remember a disk being being cleaned with common paper

Re: Cleaning RK05 packs (Was: LGP-30 Memory Drum Update)

My error did mean to say 90% just got a bit too wound up with so many suggestions that could destroy the coating. On Jan 5, 2017 7:49 AM, "Al Kossow" wrote: > 91% IPA works fine. > 99% is better though i'm skeptical it really is > >

Re: Cleaning RK05 packs (Was: LGP-30 Memory Drum Update)

We have a similar common name for it being 'brand spiritus'. It's basically 90% - 92% alcohol, with the rest being methanol and water and it's color is blue-ish. Ed -- Ik email, dus ik besta. BTC : 1J5fajt8ptyZ2V1YURj3YJZhe5j3fJVSHN LTC : LP2WuEmYPbpWUBqMFGJfdm7pdHEW7fKvDz On Thu, January 5,

RE: Cleaning RK05 packs (Was: LGP-30 Memory Drum Update)

The method I've used very successfully for unknown packs is: 1) I first mount the pack in a drive that has a good absolute filter, and has had the head load disabled, and spin it for a few hours. If the pack shows any sign of excessive vibration, it is probably no good or requires more serious

Re: Cleaning RK05 packs (Was: LGP-30 Memory Drum Update)

The method I use for RL02 packs (not sure if similar), is: - remove platter from pack - rinse it down with tap water - apply some Simple Green to a microfiber cloth - wipe the entire platter with that cloth - rinse by wiping with a 2nd cloth wet with distilled water - let dry 24 hours John

Re: Cleaning RK05 packs (Was: LGP-30 Memory Drum Update)

The cleaning procedure in the laboratory I used to work in for removing organics from silicon wafers was typically acetone, then isopropanol, then ethanol, then a deionized water rinse and nitrogen dry. We did use piranha solution on occasion when it was particularly caked on (like really old

Re: Cleaning RK05 packs (Was: LGP-30 Memory Drum Update)

>> In the US, "rubbing alcohol" is mostly denatured ethanol (though "isopropyl$ Interesting. I don't think I've ever seen a bottle of "rubbing alcohol" that was anything but isopropanol-and-water. But I'm more Canadian than US. > I would suggest avoiding these blends of random chemicals made

Re: Cleaning RK05 packs (Was: LGP-30 Memory Drum Update)

91% IPA works fine. 99% is better though i'm skeptical it really is https://www.quora.com/When-is-70-isopropyl-rubbing-alcohol-better-than-91 >> In the US, "rubbing alcohol" is mostly denatured ethanol (though "isopropyl >> rubbing alcohol" is mostly IPA), but always contains other chemicals

Re: Cleaning RK05 packs (Was: LGP-30 Memory Drum Update)

> On Jan 5, 2017, at 8:55 AM, Pete Turnbull wrote: > > On 05/01/2017 13:22, Noel Chiappa wrote: >>> From: Klemens Krause >> >>> We clean our RK05 disks in a very robust way: with cheap burning spirit >>> and paper towels. ... We rubbed away thick black

Re: Cleaning RK05 packs (Was: LGP-30 Memory Drum Update)

isopropyl alcohol works. TFE is better, if you have some stashed. If you can find them anywhere, Texwipe made a plastic wand that looks like a tongue depressor with a slit down the middle and a lint free sleeve called the Texsleeve (tx300 sleeve, tx800 wand) that you would use to clean heads

Re: Cleaning RK05 packs (Was: LGP-30 Memory Drum Update)

On 05/01/2017 13:22, Noel Chiappa wrote: > From: Klemens Krause > We clean our RK05 disks in a very robust way: with cheap burning spirit > and paper towels. ... We rubbed away thick black traces from occasional > head crashes and we never removed the oxide coating with this

Re: LGP-30 Memory Drum Update

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

Cleaning RK05 packs (Was: LGP-30 Memory Drum Update)

> From: Klemens Krause > We clean our RK05 disks in a very robust way: with cheap burning spirit > and paper towels. ... We rubbed away thick black traces from occasional > head crashes and we never removed the oxide coating with this torture. I am about to get a large batch of

Re: LGP-30 Memory Drum Update

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

Re: LGP-30 Memory Drum Update

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

Re: LGP-30 Memory Drum Update

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

Re: LGP-30 Memory Drum Update

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

Re: LGP-30 Memory Drum Update

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

Re: LGP-30 Memory Drum Update

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.

Re: LGP-30 Memory Drum Update

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

Re: LGP-30 Memory Drum Update

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.

Re: LGP-30 Memory Drum Update

> 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

Re: LGP-30 Memory Drum Update

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

Re: LGP-30 Memory Drum Update

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 >

Re: LGP-30 Memory Drum Update

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

Re: LGP-30 Memory Drum Update

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

Re: LGP-30 Memory Drum Update

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,

Re: LGP-30 Memory Drum Update

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,

Re: LGP-30 Memory Drum Update

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. >

Re: LGP-30 Memory Drum Update

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

Re: LGP-30 Memory Drum Update

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

Re: LGP-30 Memory Drum Update

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

Re: LGP-30 Memory Drum Update

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

Re: LGP-30 Memory Drum Update

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

Re: LGP-30 Memory Drum Update

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

Re: LGP-30 Memory Drum Update

> 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.

Re: LGP-30 Memory Drum Update

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

Re: LGP-30 Memory Drum Update

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

Re: LGP-30 Memory Drum Update

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

Re: LGP-30 Memory Drum Update

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

Re: LGP-30 Memory Drum Update

> 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

Re: LGP-30 Memory Drum Update

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

Re: LGP-30 Memory Drum Update

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

Re: LGP-30 Memory Drum Update

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

Re: LGP-30 Memory Drum Update

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 >

Re: LGP-30 Memory Drum Update

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

Re: LGP-30 Memory Drum Update

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

LGP-30 Memory Drum Update

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 surface preventing rotation. And in the process