OT: Who? What? Was: Re: Origin of "partition" in storage devices

[Paul Koning]

> On Feb 1, 2022, at 4:31 PM, Grant Taylor via cctalk <cctalk at classiccmp.org> wrote:
> 
> On 2/1/22 11:23 AM, Paul Koning via cctalk wrote:
>> Did any DEC MSCP disks use it?
> 
> Please expand "MSCP".  My brain is failing to do so at the moment.

Mass Storage Control Protocol, the geometry-independent storage access scheme DEC created in the early 1980s.  Early implementations include the HSC50 (for VAXclusters) and the UDA50 (Unibus adapter), talking to disk drives such as the RA80.

With MSCP, DEC switched to addressing disks by sector offset, as SCSI did later, rather than by geometry (cylinder, track, sector) on devices like the RK05 and RP06.  If the OS sees only an LBA, it doesn't matter whether the drive uses zone recording; such complexity can be hidden inside the controller firmware.  But I don't know if that was actually done, either at that time or in later generations.

	paul