[BBC-Micro] Hard or Soft Sectored Drives

[Ian Wolstenholme]

Thanks for all the info on this.  Reading a bit further
into the Adaptec manual and trying a few things out,
it seems like the Adaptec controller doesn't allow you
to set the number of sectors per track explicitly for
soft-sectored drives, it uses a preset number based
on the bytes-per-sector size specified.  So if it's 256
for use with ADFS, the number of sectors per track
will be 33 and if you change the sector size to 512
with a mode select command, mode sense will then
report a sectors per track value of 17.

Best wishes,



Ian

----- Original Message -----
From: Pete Turnbull [mailto:pete at dunnington.plus.com]
To: bbc-micro at lists.cloud9.co.uk
Sent: Fri, 22 Dec 2006 13:29:24 +0000
Subject: Re: [BBC-Micro] Hard or Soft Sectored Drives

Andrew Benham wrote:
 > I thought the original query was about hard sectored
 > HARD disks, not floppies ?
 >
 > I've found some references to hard sectored EDSI drives,
 > but not to ST506 ones.

Yes, ST506/416 drives are pretty simple devices, but some controllers 
have fixed ideas about sectors, and some SCSI and SMD drives are 
hard-sectored.

 > Superform issues the "format unit" SCSI command
 > as I recall, rather than formatting tracks or
 > cylinders or sectors.

Ah yes, that's right -- I misremembered.

-- 
Pete						Peter Turnbull
						Network Manager
						University of York

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