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

[Paul Koning]

> On Feb 1, 2022, at 6:46 PM, Jon Elson via cctalk <cctalk at classiccmp.org> wrote:
> 
> On 2/1/22 15:40, Paul Koning via cctalk wrote:
>> 
>>> 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)
> 
> All SCSI devices were logical block number, all the way back to the original SASI (Shugart Associates System Interface).  I had a 10 MB Memorex Winchester drive with SASI adapter on my Z-80 CP/M system in about 1981 or so.  Maybe I misunderstood your sentence above, what the "later" applied to.

I meant that SCSI appeared later than MSCP.  And that it used LBA addressing, but MSCP did it before SCSI.

	paul