http://www.eevblog.com/2012/12/05/ee...rive-teardown/


--

On 06/12/2012 11:59, The Other Mike wrote:
http://www.eevblog.com/2012/12/05/ee...rive-teardown/


Many moons ago, when I used to work we had these very large disk drives,
they did not have (by today's standards) a large capacity either. These
drives were very prone to "head crashes", that is the heads touched the
disk instead of skimming just over the surface. As a result not only did
the heads have to be replaced but the discs re-polished, which was a job
and a half. Thankfully it was never my task to do this.
--
Remember the early bird may catch the worm but the second mouse gets the
cheese.

On 07/12/2012 09:02, Broadback wrote:
On 06/12/2012 11:59, The Other Mike wrote:
http://www.eevblog.com/2012/12/05/ee...rive-teardown/



Many moons ago, when I used to work we had these very large disk drives,
they did not have (by today's standards) a large capacity either. These
drives were very prone to "head crashes", that is the heads touched the
disk instead of skimming just over the surface. As a result not only did
the heads have to be replaced but the discs re-polished, which was a job
and a half. Thankfully it was never my task to do this.

When I started out the site was starting to convert from EDS60 to to
EDS200 - exchangeable 60MB to exchangeable 200MB. Packs as heavy as you
could manage with one arm - I'd guess something towards 18" across - and
the drives all too similar to some top loader washing machines. And yes,
in hot tango livery.

--
Rod

Broadback :
On 06/12/2012 11:59, The Other Mike wrote:
http://www.eevblog.com/2012/12/05/ee...ost-expensive-
hard-drive-teardown/


Many moons ago, when I used to work we had these very large disk
drives, they did not have (by today's standards) a large capacity
either. These drives were very prone to "head crashes", that is the
heads touched the disk instead of skimming just over the surface. As a
result not only did the heads have to be replaced but the discs re-
polished, which was a job and a half. Thankfully it was never my task
to do this.

Those were probably exchangeable discs that were open to the atmosphere
and liable to surface contamination by tiny airborne particles. IBM's
masterstroke was the sealed enclosure as seen in the video. At first
sight it seemed extravagant to have a set of heads etc in every disk
pack, but it *was* the future.

WIWAL a disk drive was 25 MB and about the size and weight of today's
washing machines. But a *lot* more expensive.

--
Mike Barnes

On 06/12/2012 11:59, The Other Mike wrote:
http://www.eevblog.com/2012/12/05/ee...rive-teardown/


I think that should be entitled the world's most annoying presenter.

I learnt COBOL on an ICL computer in the early 1970s that had each
individual programme (it was an English machine) on a stack of
interchangeable hard disks. Each stack was about 2 feet across,
contained several disks and had its own clear plastic cover, open at the
bottom. The stacks not in use were stored off the machine and only put
onto the hard drive mechanism when required. The whole machine was
enclosed in its own clean room and only a few people were authorised to
enter it.

Colin Bignell

On Fri, 07 Dec 2012 11:05:24 +0000, polygonum wrote:

On 07/12/2012 09:02, Broadback wrote:
On 06/12/2012 11:59, The Other Mike wrote:
http://www.eevblog.com/2012/12/05/ee...ost-expensive-
hard-drive-teardown/



Many moons ago, when I used to work we had these very large disk
drives,
they did not have (by today's standards) a large capacity either. These
drives were very prone to "head crashes", that is the heads touched the
disk instead of skimming just over the surface. As a result not only
did the heads have to be replaced but the discs re-polished, which was
a job and a half. Thankfully it was never my task to do this.

When I started out the site was starting to convert from EDS60 to to
EDS200 - exchangeable 60MB to exchangeable 200MB. Packs as heavy as you
could manage with one arm - I'd guess something towards 18" across - and
the drives all too similar to some top loader washing machines. And yes,
in hot tango livery.

I did the hot tango stuff too - but mostly not running VME or DME.

But we started with 2MB exchangeable disks on the ICL [Elliott] 4130...



--
Use the BIG mirror service in the UK:
http://www.mirrorservice.org

*lightning protection* - a w_tom conductor

On 07/12/2012 11:22, Nightjar wrote:
On 06/12/2012 11:59, The Other Mike wrote:
http://www.eevblog.com/2012/12/05/ee...rive-teardown/



I think that should be entitled the world's most annoying presenter.

I learnt COBOL on an ICL computer in the early 1970s that had each
individual programme (it was an English machine) on a stack of
interchangeable hard disks. Each stack was about 2 feet across,
contained several disks and had its own clear plastic cover, open at the
bottom. The stacks not in use were stored off the machine and only put
onto the hard drive mechanism when required. The whole machine was
enclosed in its own clean room and only a few people were authorised to
enter it.

Colin Bignell
I thought your name was familiar, now I know. I remember ICL was dubbed
"It Can't Last" how right they were.

--
Remember the early bird may catch the worm but the second mouse gets the
cheese.

On 07/12/2012 11:05, polygonum wrote:
When I started out the site was starting to convert from EDS60 to to
EDS200 - exchangeable 60MB to exchangeable 200MB. Packs as heavy as you
could manage with one arm - I'd guess something towards 18" across - and
the drives all too similar to some top loader washing machines. And yes,
in hot tango livery.

Wimp! They weren't that heavy. Nice carrying handles on top, so you
could do as one guy did - have the primary and backup packs one in each
hand, then trip and fall flat on your face.

Andy

On 07/12/2012 20:44, Andy Champ wrote:
On 07/12/2012 11:05, polygonum wrote:
When I started out the site was starting to convert from EDS60 to to
EDS200 - exchangeable 60MB to exchangeable 200MB. Packs as heavy as you
could manage with one arm - I'd guess something towards 18" across - and
the drives all too similar to some top loader washing machines. And yes,
in hot tango livery.

Wimp! They weren't that heavy. Nice carrying handles on top, so you
could do as one guy did - have the primary and backup packs one in each
hand, then trip and fall flat on your face.

Andy

Truth to tell, I was always watching others carry them - and we had
several slight women ops who did look to struggle. :-)

--
Rod

On Fri, 07 Dec 2012 11:05:24 +0000, polygonum wrote:
When I started out the site was starting to convert from EDS60 to to
EDS200 - exchangeable 60MB to exchangeable 200MB. Packs as heavy as you
could manage with one arm - I'd guess something towards 18" across

I think the platters were probably 14", with the casing adding another
inch or two to that.

On 09/12/2012 02:26, Jules Richardson wrote:
On Fri, 07 Dec 2012 11:05:24 +0000, polygonum wrote:
When I started out the site was starting to convert from EDS60 to to
EDS200 - exchangeable 60MB to exchangeable 200MB. Packs as heavy as you
could manage with one arm - I'd guess something towards 18" across

I think the platters were probably 14", with the casing adding another
inch or two to that.

Something inside my brain seemed to suggest that they were twice an 8
inch floppy plus a bit! But on the basis that everything seems to derive
in one way or another from a 19-inch rack, I think that 18 inches would
not have left enough physical strength - so I will go along with "around
16 inches" - giving one and a half inches at each side.

--
Rod

On 09/12/2012 08:40, polygonum wrote:
On 09/12/2012 02:26, Jules Richardson wrote:
On Fri, 07 Dec 2012 11:05:24 +0000, polygonum wrote:
When I started out the site was starting to convert from EDS60 to to
EDS200 - exchangeable 60MB to exchangeable 200MB. Packs as heavy as you
could manage with one arm - I'd guess something towards 18" across

I think the platters were probably 14", with the casing adding another
inch or two to that.

Something inside my brain seemed to suggest that they were twice an 8
inch floppy plus a bit! But on the basis that everything seems to derive
in one way or another from a 19-inch rack, I think that 18 inches would
not have left enough physical strength - so I will go along with "around
16 inches" - giving one and a half inches at each side.


They were definitely 14 inch.

http://en.wikipedia.org/wiki/History...rd_disk_drives

Andy

On 09/12/2012 16:21, Andy Champ wrote:
On 09/12/2012 08:40, polygonum wrote:
On 09/12/2012 02:26, Jules Richardson wrote:
On Fri, 07 Dec 2012 11:05:24 +0000, polygonum wrote:
When I started out the site was starting to convert from EDS60 to to
EDS200 - exchangeable 60MB to exchangeable 200MB. Packs as heavy as you
could manage with one arm - I'd guess something towards 18" across

I think the platters were probably 14", with the casing adding another
inch or two to that.

Something inside my brain seemed to suggest that they were twice an 8
inch floppy plus a bit! But on the basis that everything seems to derive
in one way or another from a 19-inch rack, I think that 18 inches would
not have left enough physical strength - so I will go along with "around
16 inches" - giving one and a half inches at each side.


They were definitely 14 inch.

http://en.wikipedia.org/wiki/History...rd_disk_drives

Andy

I accepted that the platters are 14 inches - which means the plastic
cover would have been larger. I think.

--
Rod

On Sun, 09 Dec 2012 17:33:22 +0000, polygonum wrote:
They were definitely 14 inch.

http://en.wikipedia.org/wiki/History...rd_disk_drives

Andy

I accepted that the platters are 14 inches - which means the plastic
cover would have been larger. I think.

Yep. I found a photo of some ICL packs:

http://www.patooie.com/temp/packs.jpg

.... and the inside of one of the drives:

http://www.patooie.com/temp/drive.jpg

cheers

Jules

On 09/12/2012 19:24, Jules Richardson wrote:
On Sun, 09 Dec 2012 17:33:22 +0000, polygonum wrote:
They were definitely 14 inch.

http://en.wikipedia.org/wiki/History...rd_disk_drives

Andy

I accepted that the platters are 14 inches - which means the plastic
cover would have been larger. I think.

Yep. I found a photo of some ICL packs:

http://www.patooie.com/temp/packs.jpg

.... and the inside of one of the drives:

http://www.patooie.com/temp/drive.jpg

cheers

Jules

Looks ready to dry the washing...

--
Rod

On Sun, 09 Dec 2012 19:24:03 +0000, Jules Richardson wrote:

On Sun, 09 Dec 2012 17:33:22 +0000, polygonum wrote:
They were definitely 14 inch.

http://en.wikipedia.org/wiki/History...rd_disk_drives

Andy

I accepted that the platters are 14 inches - which means the plastic
cover would have been larger. I think.

Yep. I found a photo of some ICL packs:

http://www.patooie.com/temp/packs.jpg

... and the inside of one of the drives:

http://www.patooie.com/temp/drive.jpg

Grabbed a copy to show students. Hope that's OK!

Are you on Facebook, BTW? I have a group with various ex-UKC CompSci
students on there...



--
Use the BIG mirror service in the UK:
http://www.mirrorservice.org

*lightning protection* - a w_tom conductor

On Sun, 09 Dec 2012 20:05:55 +0000, Bob Eager wrote:
Grabbed a copy to show students. Hope that's OK!

No problem. There's a nice one of the entire system on the NMoC site:

http://www.tnmoc.org/sites/default/f...box/public/JR-
computers13.jpg

Despite the 'JR' in the filename I'm pretty sure that it's not one that I
took, though - I don't think it was long after the system was brought
into the main museum hall that I hopped across the Pond for good, and so
all of my photos show the machine in a much less presentable state :-)

Oh, I've got one here of the HDA from an RA81 drive too which they might
like (IIRC that was 14" as well):

http://www.patooie.com/temp/ra81hda.jpg

.... and one of a much larger platter:

http://www.patooie.com/temp/platter.jpg

That one was at the Centre for Computing History, but I don't recall what
system it was from now (although I could ask).

Are you on Facebook, BTW? I have a group with various ex-UKC CompSci
students on there...

Indeed I am. Chuck me an invite or however all that malarkey works (I
generally can't find anything on facebook since they imposed that whole
timeline thing on everyone!)

cheers

Jules

On Sun, 09 Dec 2012 21:09:03 +0000, Jules Richardson wrote:

On Sun, 09 Dec 2012 20:05:55 +0000, Bob Eager wrote:
Grabbed a copy to show students. Hope that's OK!

No problem. There's a nice one of the entire system on the NMoC site:

http://www.tnmoc.org/sites/default/f...box/public/JR-
computers13.jpg

Despite the 'JR' in the filename I'm pretty sure that it's not one that
I took, though - I don't think it was long after the system was brought
into the main museum hall that I hopped across the Pond for good, and so
all of my photos show the machine in a much less presentable state :-)

Oh, I've got one here of the HDA from an RA81 drive too which they might
like (IIRC that was 14" as well):

http://www.patooie.com/temp/ra81hda.jpg

... and one of a much larger platter:

http://www.patooie.com/temp/platter.jpg

That one was at the Centre for Computing History, but I don't recall
what system it was from now (although I could ask).

Are you on Facebook, BTW? I have a group with various ex-UKC CompSci
students on there...

Indeed I am. Chuck me an invite or however all that malarkey works (I
generally can't find anything on facebook since they imposed that whole
timeline thing on everyone!)

Not sure which one you are? Bemidji? Number 16 on URL?



--
Use the BIG mirror service in the UK:
http://www.mirrorservice.org

*lightning protection* - a w_tom conductor

On Sun, 09 Dec 2012 21:15:24 +0000, Bob Eager wrote:
Are you on Facebook, BTW? I have a group with various ex-UKC CompSci
students on there...

Indeed I am. Chuck me an invite or however all that malarkey works (I
generally can't find anything on facebook since they imposed that whole
timeline thing on everyone!)

Not sure which one you are? Bemidji? Number 16 on URL?

Yes, Bemidji be me! (if you mean when searching for people, it reorders
the list according to location and friends-of-friends and such, so I show
up as 1st when I do it :-)

cheers

Jules

Another thing that was so vast with IBM S/370 "old iron" were the
monster data cables, given that a SATA cable is about the size of a flat
shoelace.

My very first task at IBM (late 1975) was helping to dismantle the Data
Centre near Cavendish Square. The drives would have been 3330's and each
string needed two unwieldy cables about one-and-a half inches thick
("bus" and "tag" ISTR) with huge connectors guaranteed to snag on the
false-floor supports when you pulled them out.

--
Reentrant

On 09/12/2012 21:09, Jules Richardson wrote:
No problem. There's a nice one of the entire system on the NMoC site:

http://www.tnmoc.org/sites/default/f...box/public/JR-
computers13.jpg

**** that takes me back! Who was the bright spark who labelled two of
the EDS80s as "44"?

Andy

On 09/12/2012 17:33, polygonum wrote:
On 09/12/2012 16:21, Andy Champ wrote:
On 09/12/2012 08:40, polygonum wrote:
On 09/12/2012 02:26, Jules Richardson wrote:
On Fri, 07 Dec 2012 11:05:24 +0000, polygonum wrote:
When I started out the site was starting to convert from EDS60 to to
EDS200 - exchangeable 60MB to exchangeable 200MB. Packs as heavy as
you
could manage with one arm - I'd guess something towards 18" across

I think the platters were probably 14", with the casing adding another
inch or two to that.

Something inside my brain seemed to suggest that they were twice an 8
inch floppy plus a bit! But on the basis that everything seems to derive
in one way or another from a 19-inch rack, I think that 18 inches would
not have left enough physical strength - so I will go along with "around
16 inches" - giving one and a half inches at each side.


They were definitely 14 inch.

http://en.wikipedia.org/wiki/History...rd_disk_drives

Andy

I accepted that the platters are 14 inches - which means the plastic
cover would have been larger. I think.


Oh, I see. My mistake. Now I have to use my memory and I didn't
change them that often as I was pure software back then... but ISTR you
had to aim pretty carefully. No more than an inch all around, and I
think less than that.

Andy