Date   : Mon, 23 Jan 2006 00:13:10 +0000
From   : "Ian Wolstenholme" <BBCMailingList@...>
Subject: Re: eBay What is this?

I had noticed that *BYE wasn't doing anything.  I was working along
the lines of writing a small ROM to set the parameters after BREAK
is pressed but what I have got so far is causing more problems than
it solves, so I am looking forward to trying out the Xebec Utilities.

Best wishes,


Ian

----- Original Message -----
From: Pete Turnbull
To:  <bbc-micro@...>
Sent: Sun, 22 Jan 2006 19:13:19 GMT
Subject: Re: [BBC-Micro] eBay What is this?

On Jan 22 2006, 12:54, Ian Wolstenholme wrote:
>
> This morning I have discovered that the initialise routine was
working,
> but the disc controller parameters get reset to default every time
you
> press BREAK!!

I'd have thought that was fairly obvious, since the Xebec controller
gets the RESET signal generated by the BREAK key (or didn't you realise
that's what that key does?) :-)

There are a few other things you might want to know about using Xebecs.
 As you've realised, they don't store the disk parameters on the disk
itself, the way an Adaptec does.  The do (like an Adaptec) have a
default set of parameters -- in fact, the correct defaults for a
Seagate ST506 drive.  They don't use the same sector headers as an
Adaptec -- in fact that's true of ST412-type controllers in general,
hardly any use exactly the same headers and layout as each other, so
you often can't move a disk from one controller type/brand to another,
even in the IBM PC world.  Xebecs (and other controllers) also don't
use the same number of sectors per track as an Adaptec.  And they have
a different command set.

One consequence of that is that ADFS's *BYE command doesn't work on
Xebec controllers.  *BYE tells the Adaptec ACB4000 to park the heads --
soewthing most ST412-type drives don't do automatically the way later
ATA/IDE and SCSI drives do.

Years ago, in 1986, to be precise, when there were a number of Xebec
S1410A controlers around, I wrote a set of utilities including a
formatter, reset and park routines, and a boot program.  I sold a few
of them to potential Xebec users.  I also made and sold a few boards to
do the job of Acorn's 1MHZ Bus winchester, and bought and sold a few
Xebec controllers.  I still have the software and "manual", so if I
have time I'll try and make that available.  The formatter
documentation should be useful to you, because it will explain what
needs to be on the disk and how to ensure it's always where an
unprogrammed Xebec can get at it.  The formatter was sold as a "machine
code" program, run as a star command.  That was partly for convenience,
but actually it was a BASIC program inside a wrapper.  I'll dig out the
raw BASIC version.

It's not there yet, because I'll have to convert the VIEW document to
HTML or something, but I'll put it on my web page under
http://www.dunnington.u-net.com/public/BBC/

-- 
Pete                                           Peter Turnbull
                                               Network Manager
                                               University of York