Date   : Thu, 18 Aug 2005 20:46:22 +0100 (BST)
From   : Greg Cook <debounce@...>
Subject: Re: 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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