Origin of "partition" in storage devices

Tom Gardner tom94022 at comcast.net
Mon Jan 31 15:35:36 CST 2022

FWIW a Google search:  "partition site:http://www.bitsavers.org/pdf/dec/pdp11/rt11" returns no relevant hits prior to 1983

I suspect that ESDI and MFM controllers emulating RL/RK disks are also later than 1983


-----Original Message-----
From: Zane Healy [mailto:healyzh at avanthar.com] 
Sent: Monday, January 31, 2022 12:40 PM
To: Paul Koning; General Discussion: On-Topic and Off-Topic Posts
Cc: t.gardner at computer.org; Tom Gardner
Subject: Re: Origin of "partition" in storage devices

On Jan 31, 2022, at 11:28 AM, Paul Koning via cctalk <cctalk at classiccmp.org> wrote:
> Both of these are memory partitions.   The only OS I can think of predating the ones you mentioned is RT-11, the later versions (V2 did not have them).  When did Unix first get partitions?
> 	paul

Partitions are pretty important in RT-11 v5.x, after all, there is the partition size limit, so you have to have multiple partitions for almost any HD, except very small ones.

Let�s not forget hardware enforced partitioning, the WEQSD/04 ESDI controller comes to mind.  It see�s a single large ESDI HD as a single disk, but you can partition it on the controller, and the OS sees each partition as a separate physical disk.  I seem to remember some MFM controllers that made the MFM drive appear to be RL01/RL02 or RK05 packs.


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