Wikipedia has a long article on obscure floppy disk (diskette) formats:
https://en.wikipedia.org/wiki/Floppy_disk_variants
There's no mention of any 12 inch floppy disk format in this article. If such a
format ever existed I doubt it made it out of the labs "into the wild." I
wasn't aware until reading this article that IBM created a 4 inch format
("DemiDiskette"). DemiDiskettes barely made it out of the labs.
Could he have meant 2 inch diskettes (2 instead of 12)? I remember using a
Zenith minisPORT laptop, evidently the only machine to ever use 2 inch "LT"
format floppy disks. Unfortunately the minisPORT's LCD was not great even in
its era, so I didn't keep it long. I'm not aware of any IBM use of any 2 inch
floppy formats, mainframe-related or otherwise.
Or did he mean the IBM 2321 Data Cell's media which are 13 inches long? I think
the IBM 2321 first shipped sometime in 1965 and was withdrawn from marketing in
January, 1975. I guess you could argue the Data Cells (the media) were floppy
disk-like.
The IBM 2321 led at least indirectly to IBM Mag Cards, a smaller, also
rectangular media format that was somewhat common in IBM's high end word
processors and typewriters from the late 1960s well into the 1970s. From what I
can find IBM Mag Cards held anywhere from 5,000 to 8,000 characters depending
on the model/card. I found "Mag Card," "Mag Card/A," and "Mag Card II"
references (5,000, 6,000, and 8,000 character capacities respectively). IBM Mag
Cards were only about 7 inches long, I think. IBM Mag Cards did find some
mainframe-related use. You can find traces of that use even in today's (2024's)
IBM documentation. See here for example:
https://www.ibm.com/docs/en/cics-ts/6.x?topic=hardware-1063-magnetic-slot-reader
Are any of you still using IBM Mag Cards in conjunction with IBM CICS
Transaction Server Version 6.2 for z/OS? If you are, please post a video to
YouTube immediately! :-)
Drifting even further afield, there was the IBM 6400 Accounting Machine
announced in 1963. The 6400 used cards (30 cm x 35 cm) that were human readable
(printed) on one side and had a magnetic strip on the other side. ("You read
one side. The IBM 6400 reads the other.") You can still find examples of
similar media used today ? as single use tickets for public transport services,
for example.
?????
Timothy Sipples
Senior Architect
Digital Assets, Industry Solutions, and Cybersecurity
IBM Z/LinuxONE, Asia-Pacific
[email protected]
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