OT - "World’s Most Expensive Hard Drive Teardown"

[The Other Mike]

[Broadback]

>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.

[polygonum]

>>>

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.

[Mike Barnes]

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.

[Nightjar]

>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

[Bob Eager]

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...

[Broadback]

>>>

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

[Andy Champ]

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

[polygonum]

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

[Jules Richardson]

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

[polygonum]

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.

[Andy Champ]

They were definitely 14 inch.

[polygonum]

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

[Jules Richardson]

Yep. I found a photo of some ICL packs:

and the inside of one of the drives:

[polygonum]

Looks ready to dry the washing...

[Bob Eager]

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

[Jules Richardson]

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

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):

and one of a much larger platter:

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

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

[Bob Eager]

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

[Jules Richardson]

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

[Reentrant]

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.