[Coco] CocoSDC won't stay off

[Darren A]

John, sorry to hear about the probelms you are having. I just tried the
same steps (64K CoCo 2 with 26-3124 MPI, CoCo SDC in slot 1 and Floppy
controller in slot 4). DRIVE 0,OFF allowed me to do a DIR on the floppy
disk. After mounting a DSK image in drive 1 I entered BACKUP 0 TO 1 and it
copied the entire floppy to the SDC without error.

I read some of your previous posts regarding the difficulty you were having
in getting a floppy controller to work with your CoCo. This leads me to
believe there may still be some kind of problem with your hardware.

You also mentioned that the COPY command seems to work with small files but
not larger ones. This could be an indicator of a problem with the 6809 CPU
in your CoCo. In particular, the NMI* and HALT* signals are only asserted
during disk I/O operations. One of these may be failing intermittently and
be more likely to manifest during a longer I/O operation.

I would recommend testing with another CoCo if possibile.

- Darren

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On Tue, Dec 2, 2014 at 8:14 PM, John Goerzen wrote:

> Hi folks,
>
> I just got my Coco SDC in the mail (thanks everyone for your work on this!)
>  My first project is to copy some real floppies to the Coco SDC.
>
> I have the Multi-Pak Interface, and I managed to get a working floppy
> controller in it after some aggressive contact scrubbing.  So far, so good.
>
> So I have the SDC in slot 1, the switch set to 1, and the real floppy
> controller in slot 4.
>
> I type:
> DRIVE 0, OFF
>
> and the DRIVE command shows it off.
>
> I type
> DRIVE 1, "/NEWCOPY/GAMES.DSK"
>
> and that works.
>
> Then I type
> BACKUP 0 to 1
>
> and weird things happen.  It reads a few tracks from the real drive, then
> appears to hang.  The drive starts spinning but the light is off.  The SDC
> light is also off.  Eventually it dies with an I/O error, and any DRIVE
> commands at this point give a syntax error until I hit reset.  It's as if
> it's forgotten about the SDC commands, and the SDC entirely.
>
>