Date   : Tue, 29 Aug 2006 00:50:47 +0100 (BST)
From   : Pete Turnbull <pete@...>
Subject: Re: writing and reading on 3.5 floppy

On Aug 28 2006,  1:06, Jonathan Graham Harston wrote:
> Mike Howard <aixguru@...> wrote:
> > Wright, Chris wrote:
> > > the drive number but the 3.5" drive doesn't. The PC lead that I
have for
> > > the 3.5" drive has a twist in it for a couple of wires. Is this
part of
> > > the drive selection (when connected to a PC) ?
> >
> > I'm no expert on the workings of floppys & drive selection. I
believe
> > though, that the twist in a PC cable forces the drive to drive 0
(zero)

No, it forces it to what would be drive 2, if a Beeb used all the
possible drive selects (0,1,2,3).  But a Beeb doesn't have four drive
selects; it only has two, and what a Beeb using DFS regards as drives 2
and 3 are just the other sides of drives 0 and 1.  A modern PC (or
compatible) also has but two possible drive selects on a normal
interface, but it uses 1 and 2 (instead of 0 and 1).

> See thread on here last October subject "Floppy pinouts and
> twists", specifically a post from Pete Turnbull on 25-Oct-2005.
> See http://nelsonit.net/~jon/BBCMicro/2005/10

Also worth a look is Andrew Benham's post from a couple of days
earlier, entitled " Floppy cables: the answer".

-- 
Pete                                           Peter Turnbull
                                               Network Manager
                                               University of York