Date   : Thu, 21 Dec 2006 12:43:27 -0000
From   : BBCMailingList@... (Ian Wolstenholme)
Subject: Hard or Soft Sectored Drives

Could anybody explain the difference between hard
and soft sectored drives, in simple "DFS-user-guide-
think-of-a-disc-drive-as-a-filing-cabinet-with-drawers"
type lay language if possible!

I'm asking this because I am trying to understand
how the Adaptec controller in the Winchester disc
works in a bit more detail by dissecting Superform
and working through the Adaptec manual trying
out each of the commands in turn.

In the Mode Select command, a 22-byte data block
is sent to the controller if it's a soft-sectored drive
and a 24-byte block is used for hard-sectored or
removable drives.

Looking at Superform, it's set up for soft-sectored
drives but what is confusing me a bit is that the
final byte in the 24-byte control block is used to
set the number of sectors per track, but this 
information is not sent for soft-sectored drives.
I would have thought this sector-per-track
information would be needed for Superform to
format correctly.

Can anybody clear up this mighty confusion which
has filled my troubled mind (to misquote a Christmas
carol!)?

Best wishes,



Ian