At 17:51 13-07-98 -0700, you wrote:
>On Mon, 13 Jul 1998, Tony Duell wrote:
>
>> What we now need is for some brave person (me, Allison???) to take a
>> number of old (and dead) drives, make a clean box, pull them apart,
>> document everything, and write a repair manual....
>
>I would love to help with this effort as I'm very good with my hands and
>the whole point of starting this thread was to guage the practicality of
>home hard drive repair, but currently I wouldn't have the time to embark
>on such an endeavor, although at some point I will. I hope that whatever
>tricks I'm able to pioneer with respect to hard drive repair will be
>passed on in FAQs.
Good! We'll be watching, Sam! :-)
>
>I've already noted the discussions on building a clean box and at some
>point will be creating one. QUESTION: Is there a way to determine just
>how clean such a clean box is after its built? Is there some meter that
>can be hooked-up to the exhaust opening that will give you a particulate
Yes there is a device used to count particles in the air. But you may not
like the cost of them.
My job involves work in our Class 10,000 cleanroom at my place of
employment. A few of you others out there either once had or now work in
such a company that has cleanroom(s), or possibly had spent time in a
cleanroom as a service person.
I can give a brief primer on how a cleanroom is built and short definition
of the federal standard of cleanroom classes if some of you are interested.
That would give a picture of the environment within which the drives had
been manufactured and what one would do to make a simple one for his/her use.
We make linear encoders of which the finest line size of the ronchi ruling
on the encoder substrate is 4 microns (157.48 millionths of an inch.)
Figure one micron = 39.37 millionths of an inch (0.00003937"). Most dust
particles in 'free air' (the air we normally live in and breathe everyday)
are in the 0.5 to 10 micron range. Therefore, keeping the air _clean_
during the manufacturing process has benefited us extremely well. Of
course, semiconductor manufacturers fabricate microprocessors, transistors,
all other IC's in cleanroom environments. Those hokey Intel TV
advertisements with cleanroom workers in full body suits are actually not
far off the mark with regard to the actual need to keep a class 10 or 100
cleanroom clean when making chips with sub-micron features.
I had purchased a particle counter at work to check the "cleanness" of the
air in various zones in the cleanroom. These machines are somewhat
complicated though the basic concept used for counting particles is not.
Most particle counters are sensitive. The one I bought is able to "see",
therefore count, a *single* particle as small as 0.5 micron. Our unit has
similar specifications as other typical brands of particle counters but it
still cost us a little over US$10,000. Used equipment dealers have them for
less but it's still not reasonable for the hobbyist or even a very small
business. Maintenace parts and calibration is also a bit high.
BTW, the air quality in most areas of our cleanroom stays at less than 100
particles per cubic foot. Very clean when considering that outside air
which is relatively clean (say, the proverbial fresh mountain air) has
100,000 to 500,000 particles per cu. foot -more with forest fires, etc.
nearby.
If I do decide to tinker with some of my dead hard drives, I plan to bring
them to the plant some weekend and have at it :-) I'll just slip on a
boufont (sp.?) cap as a hair cover, special gloves, my lab coat and maybe a
face mask of some sort, setup at an empty table and away I go!
>count? My Panasonic vacuum cleaner has such a detector that triggers a
>dual-color LED on the front panel: it lights red if it detects dirt
>particles passing through the hose and green if the particle count is
>below some threshold.
This is an extremely simplified version of a particle counter. I can
envision it as having a simple LED emitter, probably IR, on one side of the
hose and a photodetector on the opposite side. The detector and the analog
front end may be rather sensitive to differentiate minute changes in light
intensity. When significant amounts of dust and crap are sucked thru the
hose the light is slightly occluded whichs lowers the output of the
photodetector which then trips the circuit driving the red LED on your
Panasonic vac. This is much too coarse of a device to measure air quality
in any home-built glovebox/cleanroom any of us may build. It serves to show
the homeowner that the Panasonic company's wonderful Model Such-and-Such is
doing a great job at cleaning their house. Pure marketing gimmick but kinda
neat on a home vac anyway IMO.
>
>> Yep, this is an interesting thread for me...
>
>Me too!
Thanks for starting the discussion Sam, as a few of us who have the
resources will need to get into it in the future -if not now. I can offer
additional ideas and advice from my own cleanroom experience to the group
on setting up a work area using either homemade or used commercial "clean
benches", etc.
Regards, Chris
-- --
Christian Fandt, Electronic/Electrical Historian
Jamestown, NY USA
Member of Antique Wireless Association
URL: http://www.ggw.org/freenet/a/awa/
I seem to remember a company way back (when the Mac Plus was considered
a power machine) that used to do custom faux finishes on Macs. The cool
one was the granite macintosh.
I think the company was also the first to make a fishtank out of a Mac
128K
Tony
> -----Original Message-----
> From: Tom Owad [mailto:tomowad@earthlink.net]
> Sent: Tuesday, July 14, 1998 12:19 PM
> To: Discussion re-collecting of classic computers
> Subject: Re: Painting Macs (was: fake NeXT)
>
>
> >I have this weird idea that one day custom paint jobs on
> computers might
> >make me some extra money. Am I crazy? Do you think there
> would ever be a
> >market for it?
>
> Absolutely! :-)
>
> I'd certainly be interested in a Mac with a neat paint job. It would
> have to be something interesting, though, after all, even I
> cold do solid
> colors. :-)
>
> A while back MacAddict gave away some custom painted Power
> Mac 5100's.
> They weren't very intersting, though, just crazy designs.
>
> Tom Owad
>
> --
> Sysop of Caesarville Online
> Client software at: <http://home.earthlink.net/~tomowad/>
>
This is off-topic, so I'd like to know if anyone would like to start a
short discussion off the list regarding data recovery on crashed hard
drives?
I recently had two hard drives go south on me. One was my 2.5" IDE in my
laptop...scary considering it had all my notes, memos and source code.
The other was a 3.5" IDE on the voicemail system in the office. The
laptop was a physical crash; the voicemail was a soft crash (directory got
over-written somehow).
I took the hard drives to a data recovery shop (Data Recovery Group in San
Leandro for the locals). They have complete clean room and repair
facilities. The data recovery technician, Yongin, opened up the 2.5" HD
in the clean room and found the head had gone bad. He assembled a new
head onto the drive but it wasn't repairable: it was a temporary fix to
get the data off. He then proceeded to extract all the directories I told
him were the most critical. Over all he said he was able to read about
60% of the 1.2GB drive.
The other drive he found had a bad root directory, apparently having been
over-written with random data (I suspect a virus). They basically used
Norton Utilities on that to locate the lost directories and re-link them.
They were able to recover the entire drive contents.
What I wanted to discuss is the possibility of doing home drive repair
without the luxury of a clean room. Is it possible to use some sort of
cheaply available or easily made vacuum chamber with positive airflow and
filtering, or is it absolutely required? Can a drive be opened in room
air and be worked on without introducing dangerous dust particles onto the
platter? Figuring out the data on the drive is the easy part, compared
with actually trying to read the data off the platter, whether the problem
be a failed head or a crashed head.
Why can't they make a hard drive that's crash proof? Even if the
mechanics fail, can't some hardend substance like glass be layed over the
platter so if the head did crash it would only scratch the glass? Then
you would simply open the drive, pull out the platter, replace the glass
shield if necessary, then insert it into a working assembly. The head
calibration would be adjusted to compensate for the extra distance to the
platter.
If anyone would like to continue this discussion, please reply to me
privately. Thanks!
BTW, the above drive repair cost $1,490 total. Not only is the job
challenging and fun, but highly lucrative. Back that data up!
Sam Alternate e-mail: dastar(a)siconic.com
-------------------------------------------------------------------------------
Ever onward.
September 26 & 27...Vintage Computer Festival 2
See http://www.siconic.com/vcf for details!
[Last web page update: 07/05/98]
Why not use a radioisotope and a metal plate, like in a smoke detector?
I think the element could be removed from the smoke detector and wired
into a different circuit that triggers on dust.
>
>I don't know how it works. For high particle counts (like your vacuum
>cleaner), I would guess you could use light scattering. I can't believe
>that would work at class 100 levels, though.
>
>-tony
>
>
______________________________________________________
Get Your Private, Free Email at http://www.hotmail.com
< What we now need is for some brave person (me, Allison???) to take a
< number of old (and dead) drives, make a clean box, pull them apart,
< document everything, and write a repair manual....
Either that or I have to trouble shoot the two maxtor2190s(rd54) I have
with seek spindown death. I know it's not a HDA problem as I opened them
and watch the gyrations.
Allison
>I have this weird idea that one day custom paint jobs on computers might
>make me some extra money. Am I crazy? Do you think there would ever be a
>market for it?
Absolutely! :-)
I'd certainly be interested in a Mac with a neat paint job. It would
have to be something interesting, though, after all, even I cold do solid
colors. :-)
A while back MacAddict gave away some custom painted Power Mac 5100's.
They weren't very intersting, though, just crazy designs.
Tom Owad
--
Sysop of Caesarville Online
Client software at: <http://home.earthlink.net/~tomowad/>
Yes the RJ-11 jack is to hard wire the keyboard. My PC Jr works
wireless okay up to four or five feet then gets flakey. Batteries
don't last long in mine either although it's been a long time since
I've played with it.
Marty
______________________________ Reply Separator
_________________________________
Subject: Re: How many computers?
Author: classiccmp(a)u.washington.edu at internet
Date: 7/14/98 11:45 AM
On Tue, 14 Jul 1998, Tony Duell wrote:
> Remmeber it was supposed to be a _home_ computer. At the time very few
> home computers came with floppy drives.
>
> BTW, how common are PC-jr machines without floppies? Were most of them
> upgraded?
Dunno, mine's got an IBM 360k drive in it. My biggest complaints about are
the 'sidecar' expansion (the second all-time-lamest computer innovation)
and the fact that all backpanel ports are.. BERG headers (the first
all-time-lamest computer innovation).
What's up with the tiny card-edge connectors inside on the motherboard?
I also noticed my keyboard (which is a joke) has an RJ-11 jack off to the
side, and that there's a 2x3 BERG header at the back labelled 'K'. Could
this be for a keyboard cable, heaven forbid?
Also, keyboard battery life is uniformly poor. It seems like I get about
20 minutes. Is this normal?
ok
r.
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To: "Discussion re-collecting of classic computers"
<classiccmp(a)u.washington.edu>
Subject: Re: How many computers?
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I suppose I'll chime in with my small collection:
Apple ][+ clone (label says "Tel-Com", the keys have CP/M, MBASIC, and
other commands silkscreened onto them)
Apple Lisa 1
Apple Lisa 2/10
DIGI-COMP 1 (an educational toy from 1963)
Osborne 1
Epson QX-16
(seeking more, as always...)
Other stuff:
Televideo 950 terminal
Power Macintosh 6100/66 (maybe as one of the first powermacs it will
have some historical significance someday. Contains a 486 DOS card.)
Generic 586 PeeCee (yawn)
This account is used so mailing lists don't
clutter up Tom's real account. If you really
want to talk to Tom, use tom(at)galena.tjs.org
