Origin of "partition" in storage devices

[Jay Jaeger]

Sent from my iPad

> On Feb 1, 2022, at 10:43, Jon Elson via cctalk <cctalk at classiccmp.org> wrote:
> 
> On 2/1/22 00:38, Peter Corlett via cctalk wrote:
>> On Mon, Jan 31, 2022 at 07:51:28PM -0500, Paul Koning via cctalk wrote:
>> [...]
>>> Yes, RT-11 is a somewhat unusual file system in that it doesn't just
>>> support contiguous files -- it supports ONLY contiguous files. That makes
>>> for a very small and very fast file system.
> 
> Well, the IBM 360 CKD disks had all files contiguous, too.
> 
> Jon
> 

That is not accurate.  CKD files (and FBA files, for that matter) can have multiple *extents*.  An extent is contiguous by nature, but if a file has multiple extents it is not contiguous other than by coincidence.

Side note:  Intergraph made disk controllers for the PDP11 and Vaxen that required graphics files (IGDS) to be contiguous so that the on-board CPU could scan for graphic element characteristics (layer, type, etc.)