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IBM System 360 12-inch floppy disks?

vwestlife

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On my video about the genius design of the 3.5" floppy disk, one guy is insisting that he used 12-inch floppy disks with an IBM 360 mainframe:

"The first floppies I used were the 12 inch floppy disc with IBM programs on them. They were buggers to keep safe and usable."

I asked if he meant 8-inch floppy disks, and he replied, "nope I mean 12 inch floppy. Came with the hardware and were prerecorded with some of the software for the 360 systems." He then elaborated:

Back in the early 1980s I worked for a company that did 3rd party computer maintenance on mainframe gear from the 1960s and 1970s, most of it was IBM systems. There were a bunch of tape systems and 12 inch disk packs used for customer data and daily uses - those disk packs were originally 100 Mb and later grew bigger. However, I was also given a case of pre-recorded 12 inch floppy discs to keep locked up unless authorised by the manager for issue to the senior techs as they contained some hard to get machine code to set-up the system again after a major problem. I'm pretty sure they were for the IBM 360 systems as that was what we mostly looked after. Without those disc and the fancy machine they put it in and hooked up to the system it was a VERY expensive job and time consuming to get the IBM techs to do the job, and if we needed the top IBM techs that meant waiting while they flew across the Pacific Ocean.

At that time I was in charge of the logistics operation and all I did with the huge suckers was to keep them safe and secure in a fireproof safe along with the case holding the machine they were used in.

The secured discs were bigger than 8 inch floppies as I had them on the shelf for general issue and use by the techs so I know they were bigger and they looked the same size as a LP or the disc packs.

Here's another thread asking about these alleged IBM 12-inch floppy disks, but no one could dig up any proof of them existing:


So what's the deal? Did such a thing actually exist? The Museum of Obsolete Media has documented virtually every kind of floppy disk known to exist, but there's no mention of anything larger than 8 inches:

 
This is one that crops up occasionally. I think that it's at the level of an urban legend. S/370 shipped firmware on read-only 8" media, but a bit different from 3740 media--the sector holes were near the outer edge of the cookie. cf. IBM 23FD. Somewhat similar to the Memorex 650.
 
Some of the IBM disk packs and cartridges used 14" non-flexible platters. I once found a Burroughs patent for 12" flexible disk packs but never found any evidence of a prototype being made or a single disk variant designed. https://patents.google.com/patent/US4823215 looks like one of the Burroughs patents. There was a repeated rumor that DEC experimented with a 9" floppy design before adopting the 8" design with the RX01.
 
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There's no way you're going to confuse a 2311 disk pack with a floppy, however. Same for a 2310 cartridge drive.
IBM may have invented the digital floppy disk, but the audio floppy disk dates back to the early 1950s.
 
Some of the 5440 related designs were quite modest in size. If one didn't pick up the cartridge and notice it does not flex, it would be a challenge to realize that it wasn't an oversized floppy disk for an oversized floppy drive.
 
Some of the 5440 related designs were quite modest in size.

Please give an example of what a "5440 related design" would be?
The 5440 was a top loading cartridge design done at IBM Rochester which was used instead of the front-loading 2315
They used rectangular rather than 'monkey face' round heads. The tech is what DEC used for the RL01 but using an embedded servo.
They all use 14" hard-sectored media, which was pretty much the standard until IBM moved to 8" platters in their small Winchesters.
The industry mostly followed in IBM's head technology footsteps for heads and media.
Someone just asked me if their were other platter sizes smaller than 14, and the only one I could think of were the platters in
Fujitsu Eagles.
 
CHM just got a donation of all of the ENDL newsletters, which was the primary source of insider info for
the disk business. I need to look through those.
 
This is one that crops up occasionally. I think that it's at the level of an urban legend. S/370 shipped firmware on read-only 8" media, but a bit different from 3740 media--the sector holes were near the outer edge of the cookie. cf. IBM 23FD. Somewhat similar to the Memorex 650.
I found a manual for a Century Data floppy that seems to match the specs for the IBM Minnow.
It spun really slowly (90rpm) and had a low track density (66)
 
Another platter size less than 14" but more than 8" was 10.5" used by a number of Honeywell-Bull designs in the late 70s to early 80s. CDC had a removable disk pack variation on their 9" hard drive design.

I was considering the RL01 as an example of a smaller cartridge drive since it took up the same rack space as a pair of 8" floppy drives. From a distance, if someone hadn't used it, it isn't too unexpected to be mistaken for a floppy drive. In some versions of the oversized floppy story, the disks are claimed to be stored in 9-track covers which makes it obvious that a cartridge platter was the source for the memory of the big floppy.
 
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Al, that Century Data drive looks like a knockoff of the Minnow. But 90 RPM with a 33KHz data rate? Wow.

As far as early flexible disks, I note that CHM has a BD-103 from LFE. I'd heard about it, but never thought that it was actually produced as a product. A bit more here. The disk was evidently non-removable. In 1960, the attraction must have been for portability of the unit.
 
I think I've found a picture of this elusive disk. Twelve inches was a bit of an understatement.

yap-3de5582da4f8b2e30812beb5aee6e672d3edde00-s800-c85.webp
 
No that's a Flintstones LP record, you play it with a birds beak.
 
Well there was a 12"(?) square removable disk cartridge for the General Electric GE-115 called the DS-12:
https://archive.org/details/TNM_Gen...mputer_Overview_and_Brochure/page/n5/mode/2up
It certainly looks like a giant floppy disk.
According to the Auerbach report from 1965, the DS-12 can only read one side of the disc but has data on both. Changing a disc cartridge was fraught with danger. Expecting the operator to routinely flip the disc seems likely to cause a lot of head crashes, not the sort of behavior that would result in operational drives in 1980.
 
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