8 Apr
2007
8 Apr
'07
8:20 a.m.
Subject: Re: ST506 WTB:Micropolis 1325
From: "Steven N. Hirsch" <shirsch at adelphia.net>
Date: Sat, 07 Apr 2007 08:42:34 -0400 (EDT)
To: "General Discussion: On-Topic Posts Only" <cctech at
classiccmp.org>
On Thu, 5 Apr 2007, Sridhar Ayengar wrote:
I have several miniscribe 20mb in all flavors of interface st412, SCSI
and IDE. I have some really old 3.5" WD 10mb. to name a few.
They show up around the beginning of the IDE era but by time IDE hit 40mb
they seemed to have disappeared.
Allison
John Kourafas wrote:
I have an extensive collection of MFM/RLL drives and have _never_ run
across one with that interface in a 3.5" form-factor. Not sure that
anything of this sort existed. 5.25" 1/2-ht. was about as sophisticated
as they got. Also looking for a Micropolis 1325 MFM Drive,
71/80MB , I've seen both the
ST506 and Mic. 1325 on eBay for like 600.00 which I think is crazy...
What's the largest capacity 3.5" MFM HDD available? 
9 Apr
9 Apr
5:17 a.m.
Allison, All,
I have a similar problem with two ESDI Micropolis 1355 drives both driver
exhibit the same problem as you describe
Fault
====
The drives power up but just seem to fail to load the heads
i.e. You know that voice coil noise when a working drive loads, well it just
does not happen on the faulty drives. The drives spins up but the drive
access light just stays on. After a while the drives re-tries to load, the
drive spins down the spins up again but still fails to load the head.
I have two drives with this problem, however both were working but failed
after a few hours of running (Not including all the years in service ;-),
and one still intermittently still works.
I had a quote to have the drive repaired but the UK firm wanted 380 UK
Pounds!
So anyway sorry to ramble, After you opened the drive, did you have any
problems with dust and head crashes? Do you think that it would be possible
to fabricate one of these bumpers? Do you have any pictures of this bumper
within the drive?
Thanks,
Andy.\
On 08/04/07, Allison <ajp166 at bellatlantic.net> wrote:
I have an extensive collection of MFM/RLL drives and have _never_ run
across one with that interface in a 3.5" form-factor. Not sure that
anything of this sort existed. 5.25" 1/2-ht. was about as sophisticated
as they got.
I have several miniscribe 20mb in all flavors of interface st412, SCSI
and IDE. I have some really old 3.5" WD 10mb. to name a few.
They show up around the beginning of the IDE era but by time IDE hit 40mb
they seemed to have disappeared.
Allison
Subject: Re: ST506 WTB:Micropolis 1325
From: "Steven N. Hirsch" < shirsch at adelphia.net>
Date: Sat, 07 Apr 2007 08:42:34 -0400 (EDT)
To: "General Discussion: On-Topic Posts Only" <cctech at classiccmp.org
On Thu, 5 Apr 2007, Sridhar Ayengar wrote:
> John Kourafas wrote:
>> Also looking for a Micropolis 1325 MFM Drive, 71/80MB , I've seen both
the
ST506 and Mic. 1325 on eBay for like 600.00 which I
think is crazy...
What's the largest capacity 3.5" MFM HDD available? 
9:42 a.m.
Andy Piercy wrote:
So anyway sorry to ramble, After you opened the drive,
did you have any
problems with dust and head crashes? Do you think that it would be possible
to fabricate one of these bumpers? Do you have any pictures of this bumper
within the drive?
You could always make a cleanbox to do the work in. It isn't difficult.
There are plans available online, but if you have trouble finding
them, I'd be willing to describe how I did it.
Peace... Sridhar
7:15 p.m.
Alison, thanks for the info, I'll have a go at opening one of the driver, as
currently they are only as much use as a large paper weight!
Sridhar,
A clean box sounda a good idea, could you provide some detaile please?
Thanks,
Andy.
On 09/04/07, Sridhar Ayengar <ploopster at gmail.com> wrote:
Andy Piercy wrote:
So anyway sorry to ramble, After you opened the
drive, did you have any
problems with dust and head crashes? Do you think that it would be
possible
to fabricate one of these bumpers? Do you have
any pictures of this
bumper
within the drive?
You could always make a cleanbox to do the work in. It isn't difficult.
There are plans available online, but if you have trouble finding
them, I'd be willing to describe how I did it.
Peace... Sridhar
10 Apr
10 Apr
2:50 a.m.
New subject: How to Build a Clean Box
Andy Piercy wrote:
Alison, thanks for the info, I'll have a go at
opening one of the
driver, as
currently they are only as much use as a large paper weight!
Sridhar,
A clean box sounda a good idea, could you provide some detaile please?
Andy,
Basically, the purpose of the clean box is to ensure that the air you're
working in is clean. The box should be made from something that won't
turn readily into dust, for example, it should *not* be made of
cardboard. Plastic works best.
Also, the box should have at least one clear side. I used perspex for
the sides and top and thick rigid PVC for the base. It's important for
you to be able to see what you're working on.
Third, it's important to get the box sealed up well, so use plenty of
thick silicone sealant along the corners. And make real sure that the
silicone is completely and thoroughly dry and set up before you use the
clean box. It also couldn't hurt to join the corners on a miter. In
mine, I use a false bottom that holds together with some bolts to make
it easier to open and close the box, so I can get tools and items to be
repaired in and out of the box.
Fourth, it's a good idea to use an inert gas supply. For reasons of
availability and price, the best choice might be nitrogen. Bottled
nitrogen won't be completely clean, so an air filter is probably a good
idea. Don't use a paper one, obviously. I use a glass allergen filter.
And the gas should go through a regulator. If it comes out too
quickly, it could get supercooled, and that would not be fun. And don't
forget to create a gas outlet with a one-way valve, to prevent outside
air from getting in. If you don't put in an outlet, the gas will find
its own outlet, and that won't be good.
Obviously, it isn't possible to work in a completely sealed cube. You
also need a place to put your hands into the box to actually *do* the
work. The most reasonable method for doing this is to attach a pair of
gloves to the box itself. Again, getting a good seal between the box
and the glove is of paramount importance. Use a sealant material which
has enough flexibility to do the job. Also, it would be a good idea to
have a way of changing the gloves without tearing the box apart. I
mounted my gloves to the box on opposite ends of the box so that I can
get my hands to anywhere in the box. One thing I didn't think of until
after I had built the box is that the positive pressure inside the box
doesn't have to be very high, so you don't have to use gloves that are
very rigid. I used pipefitters' gloves the first time, and I lost a lot
of fine control. I suggest using something much thinner.
Experiment! It's the easiest way to figure this stuff out. And let me
know how it goes. I'd be interested to know. Good luck.
Peace... Sridhar
> > So anyway sorry to ramble, After you opened
the drive, did you have any
> > problems with dust and head crashes? Do you think that it would be
> possible
> > to fabricate one of these bumpers? Do you have any pictures of this
> bumper
> > within the drive?
>
> You could always make a cleanbox to do the work in. It isn't difficult.
> There are plans available online, but if you have trouble finding
> them, I'd be willing to describe how I did it.
3:16 p.m.
New subject: How to Build a Clean Box
On Tue, 10 Apr 2007, Sridhar Ayengar wrote:
Also, the box should have at least one clear side. I
used perspex for
the sides and top and thick rigid PVC for the base. It's important for
you to be able to see what you're working on.
Harbor Freight sells some VERY cheap abrasive blast cabinets, that already
have a window, gloves, fittings that can be adapted, etc. do NOT try it
with a used one!
air from getting in. If you don't put in an
outlet, the gas will find
its own outlet, and that won't be good.
prssure relief is essential.
But, the positive pressure in it will ensure that any leaks are flowing
outwards.
--
Grumpy Ol' Fred cisin at xenosoft.com
3:57 p.m.
New subject: How to Build a Clean Box
Fred Cisin wrote:
On Tue, 10 Apr 2007, Sridhar Ayengar wrote:
Do you have a SKU?
Peace... Sridhar
Also, the box should have at least one clear
side. I used perspex for
the sides and top and thick rigid PVC for the base. It's important for
you to be able to see what you're working on.
Harbor Freight sells some VERY cheap abrasive blast cabinets, that already
have a window, gloves, fittings that can be adapted, etc. do NOT try it
with a used one!
6:59 p.m.
New subject: How to Build a Clean Box
> Harbor Freight sells some VERY cheap abrasive
blast cabinets, that already
> have a window, gloves, fittings that can be adapted, etc. do NOT try it
> with a used one!
On Tue, 10 Apr 2007, Sridhar Ayengar wrote:
Do you have a SKU?
They seem to have discontinued the one that I had in mind, but for
small stuff, like microcomputer drives, look at
something like #45411 $89.99
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=45411
or #94978
They USTA have some nice big ones. For some of your stuff, you might want
to consider using filtered air, and making one out of a 20 foot shipping
container!
--
Grumpy Ol' Fred cisin at xenosoft.com
8:59 p.m.
New subject: How to Build a Clean Box
Fred Cisin wrote:
Hmm. I think I'll stick with the ones I built myself. They cost about
1/10 of that much.
> Harbor
Freight sells some VERY cheap abrasive blast cabinets, that already
> have a window, gloves, fittings that can be adapted, etc. do NOT try it
> with a used one!
On Tue, 10 Apr 2007, Sridhar Ayengar wrote:
Do you have a SKU?
They seem to have discontinued the one that I had in mind, but for
small stuff, like microcomputer drives, look at
something like #45411 $89.99
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=45411
or #94978 They USTA have some nice big ones. For some of your
stuff, you might want
to consider using filtered air, and making one out of a 20 foot shipping
container!
8-)
I think at that point, it's no longer a clean box, but a clean *room*.
Peace... Sridhar
5:50 p.m.
New subject: How to Build a Clean Box
G'Day,
On 10/04/07, Sridhar Ayengar <ploopster at gmail.com> wrote:
[construction of a clean box]
Fourth, it's a good idea to use an inert gas
supply. For reasons of
availability and price, the best choice might be nitrogen. Bottled
nitrogen won't be completely clean, so an air filter is probably a good
idea. Don't use a paper one, obviously. I use a glass allergen filter.
And the gas should go through a regulator. If it comes out too
quickly, it could get supercooled, and that would not be fun. And don't
forget to create a gas outlet with a one-way valve, to prevent outside
air from getting in. If you don't put in an outlet, the gas will find
its own outlet, and that won't be good.
Just a small thing about the inert gas supply - if you do this make
sure it is in a well ventilated space - otherwise you will feel sleepy
and possibly never wake up. This would be a bad thing.
There seem to be lots of hepa filters on the market so getting a good
clean gas supply should not be too difficult.
Don't use an air compressor - they have a tendency to put oil in the
air and you run the risk of having condensation come out of the air
supply. There are ways to remove the oil and water, but if you can
afford to do this, a clean room is pretty simple.
[Rest of excellent advice on building a clean box].
Simon
--
------------------------------------------------------------------------
"Well, an engineer is not concerned with the truth; that is left to
philosophers and theologians: the prime concern of an engineer is
the utility of the final product."
Lectures on the Electrical Properties of Materials, L.Solymar, D.Walsh
8:51 p.m.
New subject: How to Build a Clean Box
Simon Fryer wrote:
G'Day,
On 10/04/07, Sridhar Ayengar <ploopster at gmail.com> wrote:
[construction of a clean box]
If you're using enough nitrogen to suffocate yourself, you're using
*waay* too much nitrogen. It doesn't take that much.
Peace... Sridhar
Fourth, it's a good idea to use an inert gas
supply. For reasons of
availability and price, the best choice might be nitrogen. Bottled
nitrogen won't be completely clean, so an air filter is probably a good
idea. Don't use a paper one, obviously. I use a glass allergen filter.
And the gas should go through a regulator. If it comes out too
quickly, it could get supercooled, and that would not be fun. And don't
forget to create a gas outlet with a one-way valve, to prevent outside
air from getting in. If you don't put in an outlet, the gas will find
its own outlet, and that won't be good.
Just a small thing about the inert gas supply - if you do this make
sure it is in a well ventilated space - otherwise you will feel sleepy
and possibly never wake up. This would be a bad thing. 
6:20 p.m.
New subject: How to Build a Clean Box
Fourth, it's a good idea to use an inert gas
supply. For reasons of
What's wrong with filtered air? It's what was used in the demountable
minicomputer hard disks, and I would think it would be suitable for the
sort of winchester drive we're discussing here.
availability and price, the best choice might be
nitrogen. Bottled
nitrogen won't be completely clean, so an air filter is probably a good
idea. Don't use a paper one, obviously. I use a glass allergen filter.
Again, why not? Every demountable hard drive I've ever worked on has used
a coated paper element air filter. The service manual for at least one
hard dirve (I have the manual, not the drive, I think it was the drive
badged as the RK01) has a hadwritten note in it giving the make/model of
a car, the air filter of which would work in said drive. And I am told A
Citroen something-or-other air filter can be modified to fit an RL drive.
-tony
8:55 p.m.
New subject: How to Build a Clean Box
Tony Duell wrote:
Quite probably, but I constructed my clean box to work on stuff other
than just hard disks.
Well, I've seen how much dust a car air filter lets through, and I won't
use one on my car anymore. 8-/
Do the heads on older drives hover closer or farther from the data
surface than on newer drives?
Peace... Sridhar
Fourth,
it's a good idea to use an inert gas supply. For reasons of
What's wrong with filtered air? It's what was used in the demountable
minicomputer hard disks, and I would think it would be suitable for the
sort of winchester drive we're discussing here. availability
and price, the best choice might be nitrogen. Bottled
nitrogen won't be completely clean, so an air filter is probably a good
idea. Don't use a paper one, obviously. I use a glass allergen filter.
Again, why not? Every demountable hard drive I've ever worked on has used
a coated paper element air filter. The service manual for at least one
hard dirve (I have the manual, not the drive, I think it was the drive
badged as the RK01) has a hadwritten note in it giving the make/model of
a car, the air filter of which would work in said drive. And I am told A
Citroen something-or-other air filter can be modified to fit an RL drive.
11 Apr
11 Apr
5:06 p.m.
New subject: How to Build a Clean Box
Do the heads on older drives hover closer or farther from the data
surface than on newer drives?
The higher the bit density, the lower the flying height of the heads. So
in general, modern drives fly the heads a lot lower than old ones.
I don;'t think you're going to get away with this on say, a 3.5" 80GByte
drive :-). But those are not the drives we're discussing here. For the
old 40MByte 5.25" units, etc, you will have a lot less problems.
I'd not use a car eir filter either. But I think the sort of filter used
in the demountable hard drives would be fine as an input filter on the
clean box.
-tony
6:53 p.m.
New subject: How to Build a Clean Box
On 11 Apr 2007 at 22:06, Tony Duell wrote:
I'd not use a car eir filter either. But I think
the sort of filter used
in the demountable hard drives would be fine as an input filter on the
clean box.
Most modern vacuum cleaners (yes, even the Hoovers) are equipped with
HEPA filters on the exhaust side, particularly the "bagless" ones.
So they're not particularly difficult to find as replacement items.
Cheers,
Chuck
8:41 p.m.
New subject: How to Build a Clean Box
some thoughts:
for convenience (i.e comfort) perhaps a
circular/tubular "box" isn't such a bad idea, but
higher at the rear then towards the operator, then
secure a plexiglass top. The stuff they sell at Home
Depot goes by a different name, and it escapes me at
the moment. Comes in sheets of different sizes.
Holes placed at convenient spots in the sides/front
of the tube as glove-holes.
If I have the proper understanding, you'd have an
inlet (for the gas supply) and outlet. Therefore the
pressure of the entering gas would have to be
sufficiently higher then the ability of gas to escape
through the outlet. How would you control this? By
using a smaller outlet then the inlet? Oi do I make
any sense? In any event it seems you'd have to utilize
filters for both ports.
____________________________________________________________________________________
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12 Apr
12 Apr
5 a.m.
New subject: Off-topic Air filters, was Re: How to Build a Clean Box
On Tue, 2007-04-10 at 20:55 -0400, Sridhar Ayengar wrote:
Well, I've seen how much dust a car air filter
lets through, and I won't
use one on my car anymore. 8-/
What, no air filter at all? Doesn't that make the engine run rather
lean, with lots of pinking and eventually holes in the piston crowns?
Gordon (who has seen it happen)
10 Apr
10 Apr
9:34 p.m.
New subject: How to Build a Clean Box
>
> A clean box sounda a good idea, could you provide some detaile please?
We use the same techniques in Mushroom innoculation, working in a
stream of clean air from a HEPA Filter. It is called Laminar Flow.
Here are pictures of some we use in Mushroom Work.
http://www.fungi.com/tools/airfilters.html
The series 1 hood can be homebuilt. These people have filters for $90
for new ones.
You work right in front of the filter in the clean airstream coming out.
I would have no qualms about opening a HD inside a stream of clean
air, I don't think there is a need for inert gas. Static electricity
is a minor concern, you want to work in a grounded environment.
More critical is working downstream of the drive in the airflow and
moving slowly. A plexiglas shield may be handy.
Here is one on Ebay if you are close, shipping would be expensive.
http://cgi.ebay.com/HEPA-Filter-Fan-Unit-Laminar-Flow-Hood-Mushroom-Growing…
Item number 290103957001 if the link breaks. This is a very high grade
filter, Class 100.
Used hoods are often used for mushroom work as they are often
replacements for semiconductor fabs that are updated regularly. I used
to get Filters and hoods from intel and sold them into the fungi
market and/or the semiconductor market.
Personally I use a homebuilt Laminar Flow Hood with a 12 inch by 12
inch HEPA filter (came off a Fujitsu drive line) with a small
squirlcage blower that I can control the speed of. The goal is to
maintain about 1 pound of pressure above ambiant between the blower
and the intake of the filter. This generates the even flow through the
filter.
--
Paxton Hoag
Astoria, OR
USA
6293
days inactive
6297
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18 comments
11 participants
participants (11)
-
ajp166＠bellatlantic.net -
andy.piercy＠gmail.com -
ard＠p850ug1.demon.co.uk -
cclist＠sydex.com -
chrism3667＠yahoo.com -
cisin＠xenosoft.com -
fryers＠gmail.com -
gordon＠gjcp.net -
innfoclassics＠gmail.com -
kth＠srv.net -
ploopster＠gmail.com