A somewhat broader search found the 1984 RT-11 System Release Notes with the following:
1.4.2.4 Logical Disk Subsetting Handler (LD) - The logical disk subsetting handler lets you define logical disks, which are subsets of physical disks. You define logical disks by assigning a logical disk unit number to a file on a physical disk. You can then use the logical disk as though it were a physical disk. AA-5286F-TC-T1_RT-11_System_Release_Notes_Jul84.pdf (bitsavers.org) <http://www.bitsavers.org/pdf/dec/pdp11/rt11/v5.1_Jul84/AA-5286F-TC-T1_RT-11_System_Release_Notes_Jul84.pdf> p15/102 Suggests DEC had not yet adopted the term “partition” for a segment of a disk Tom -----Original Message----- From: Tom Gardner [mailto:tom94...@comcast.net] 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 Tom -----Original Message----- From: Zane Healy [ <mailto:heal...@avanthar.com> mailto:heal...@avanthar.com] Sent: Monday, January 31, 2022 12:40 PM To: Paul Koning; General Discussion: On-Topic and Off-Topic Posts Cc: <mailto:t.gard...@computer.org> t.gard...@computer.org; Tom Gardner Subject: Re: Origin of "partition" in storage devices On Jan 31, 2022, at 11:28 AM, Paul Koning via cctalk < <mailto:cctalk@classiccmp.org> cctalk@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. Zane
