[Coco] DSKINI glitch while using physical drive 1 and SDC DOS 1.5

Arthur Flexser flexser at fiu.edu
Sun Sep 3 17:08:02 EDT 2017


Never mind, Rietveld, Darren's explanation is undoubtedly correct.  If it
were the interrupts, you'd have gotten the OK prompt afterwards.  I didn't
read the exchange carefully enough.

Darren, I ran into a similar situation with Ext. ADOS-3, and went to the
solution of putting the CPU into double-speed mode at the begining of
DSKCON, so that all disk operations occur at double speed.  You may have
been reluctant to do that, wondering how to restore the speed back to its
former value on exit from DSKCON, since the speed register isn't readable.

I used the speed detection method within DSKCON of counting how many
horizontal interrupts occurred while a short loop executed.  I can send
this very short routine if you like.  Occasionally, the CPU halting throws
the count off, in which case you get a screwy value and have to repeat the
count.  With that modification, speed detection is highly reliable, and the
gain from operating at double speed within DSKCON more than compensates for
the extra processing time taken up by the addition of the speed detection
routine that is executed on entry..

Art


On Sun, Sep 3, 2017 at 2:56 PM, Rietveld Rietveld <rietveldh at hotmail.com>
wrote:

> Thanks.   I will try this when I get home and report back
>
> Sent from my BlackBerry Passport Red Edition.
>   Original Message
> From: Arthur Flexser
> Sent: Sunday, September 3, 2017 1:44 PM
> To: CoCoList for Color Computer Enthusiasts
> Reply To: CoCoList for Color Computer Enthusiasts
> Subject: Re: [Coco] DSKINI glitch while using physical drive 1 and SDC DOS
> 1.5
>
>
> Rietveld, you can check if the interrupts being off is the problem by
> printing out the value of the TIMER function a few times.  If it isn't
> changing, that's the problem.  Try a POKE&HFF03,&H35 (from memory, hope
> that's right) and see if the disk motor shuts off and the TIMER function
> starts working again.
>
> In any case, you can "manually" shut off the disk motor with POKE&HFF40,0.
>
> Art
>
> On Sun, Sep 3, 2017 at 1:35 PM, Rietveld Rietveld <rietveldh at hotmail.com>
> wrote:
>
> > So far I have just waited until the head stop stepping. That way I know
> > the formatting is complete. But motor stays on even after stepping is
> > done.   A reset and DIR1 confirms a successful DISINI format
> >
> >
> > Sent from my BlackBerry Passport Red Edition.
> >   Original Message
> > From: Darren A
> > Sent: Sunday, September 3, 2017 1:13 PM
> > To: CoCoList for Color Computer Enthusiasts
> > Reply To: CoCoList for Color Computer Enthusiasts
> > Subject: Re: [Coco] DSKINI glitch while using physical drive 1 and SDC
> DOS
> > 1.5
> >
> >
> > On Sun, Sep 3, 2017 at 10:56 AM, Rietveld Rietveld wrote:
> >
> > > Just 'hangs'. No 'ok' prompt until I do a reset
> > >
> > >
> > But can you hear the drive head stepping occasionally?
> > Try setting the appropriate High-Speed poke for your CoCo before doing
> the
> > DSKINI and see if that makes a difference.
> >
> > High-Speed poke for CoCo 1 or 2:
> >   POKE  65495,0
> >
> > High-Speed poke for CoCo 3:
> >   POKE  65497,0
> >
> >
> > - Darren
> >
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