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From: "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com>
Newsgroups: comp.arch
Subject: Re: Where did CKD disks come from?
Date: Fri, 13 Dec 2024 00:04:24 -0800
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On 12/12/2024 11:55 PM, Lynn Wheeler wrote:
> John Levine <johnl@taugh.com> writes:
>> Any idea who invented CKD?  The Pugh et al history book says a lot about
>> disk hardware but nothing about software or CKD.  Someone must have invented
>> it but who?  When?
> 
> not who but why:
> https://retrocomputing.stackexchange.com/questions/24074/how-did-reserve-tracks-work-on-early-hard-disks
> Count Key Data was IBM's answer to unify three very different methods of
> data storage (Disk, Drum, Cells) into a single interface, while at the
> same time offloading basic tasks to hardware.
> 
> discussion "spare tracks" & "standard configuration"
> https://archive.computerhistory.org/resources/access/text/2014/07/102739924-05-03-acc.pdf
> Jack: That was the first time in a sense that you had an index, which is now
> standard configuration.
> Al: Right.
> Jack: Standard configuration. The other thing that we did, that we
> subsequently cursed a lot, was the idea of variable record length and count
> key data as the format. I don't know if IBM's gotten rid of that yet.
> 
> ... seems to imply collective "we" team/group
> 
> and more discussion of 1301&1311 to CKD 2311 (disk)
> https://archive.computerhistory.org/resources/text/Oral_History/IBM_1311_2311/IBM_1311_2311.oral_history.2005.102657931.pdf
> 

For some damn reason this makes me think of fuzzy bits on a disk. I am 
not sure why!

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