Date   : Thu, 18 Aug 2005 21:56:45 +0100
From   : "David Hunt" <dm.hunt@...>
Subject: Re: FDC status register test - please help

A slight aside to this, I used to have a Cumana QFS board, I think it had a
WDC1772 controller. If you did *. and then pressed BREAK before the
catalogue appeared it would delete the first sector of track 0 !!!

I wonder if that is related to what you are seeing, maybe those boards use a
different "1770" ?

Anyhows, I lost a few discs before I ripped it out of the machine and
stamped on it - and bought something almost as bad, a Solidisk DFDC...

Dave ;)

-----Original Message-----
From: Majordomo List Manager [mailto:majordomo@...] On Behalf Of
Greg Cook
Sent: 18 August 2005 20:46
To: bbc-micro@...
Subject: Re: [BBC-Micro] FDC status register test - please help

On Thu, 18 Aug 2005 12:16:04 +0100, Rob <robert@...> wrote:

> At 09:29 18/08/2005, Greg Cook wrote:
> 
> >Of course *slaps forehead*, the controller is interrupted after
> >official ops.  For anyone interested, here's a revised test that
> >performs two seeks:
> >
> >*HELP
> >?&FE84=&C
> >PRINT "A=&"; ~?&FE84
> >?&FE87=&27
> >?&FE84=&1C
> >PRINT "B=&"; ~?&FE84
> 
> On that one, both A & B return &80 for me ..

The test isn't going as well as planned.  I was hoping for a result
like A=&24, B=&20, or vice versa which would mean the track register
has been inverted.  It would need some playing with a machine to get to
the bottom of this.  Maybe at next year's show...

As an aside, a status of &80 is odd coming twice, from a 1770.  It
ought to mean Motor On, but then the Track 0 bit should have toggled.

Greg



               
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