Re: Where did CKD disks come from?

EricP <ThatWouldBeTelling@thevillage.com> writes:

It's the 2841 Storage Control Unit that actually creates the CKD records.
The manual referenced below says that it does CKD on a 2311 disk and
2302 disk, but also a 2321 Data Cell Drive and a 7320 Drum drive.
Document A26-5988-0 is the earliest reference I could find from 1965,
but doesn't say where the idea came from.

univ got 360/67 with 2301 drum and bank of 2314 drives (replacing
709/1401) originally for tss/360 ... never came to production so ran as
360/65 ... when it arrived, I was hired fulltime responsible for os/360.

univ library then got an ONR grant to do an online catalog and some of
the money went for 2321 datacell ... also was selected as one of the
betatest sites for original CICS transaction processing product (and
CICS debugging/support was added to my tasks).

when IPL'ing, 2321 made distinct sound as os/360 read the volser
of each cell ... whirl, kerchuk, whirl, kerchuk, ....

2303 drum ran off same controller (2821) as used for 2311s ... 2301 was
similar to 2303 but read/wrote four tracks in parallel (four times the
transfer rate, 1/4 the number of "tracks" and each "track" four times
larger and needed its own controller)
https://en.wikipedia.org/wiki/IBM_drum_storage
https://en.wikipedia.org/wiki/History_of_IBM_CKD_Controllers

--
virtualization experience starting Jan1968, online at home since Mar1970