[Coco] DriveWire problem

[Steven Hirsch]

On Sun, 14 Feb 2016, Aaron Wolfe wrote:

> On Sun, Feb 14, 2016 at 5:07 PM, Steven Hirsch <snhirsch at gmail.com> wrote:
>
>>
>> The DW GUI is showing pairs of messages:
>>
>> Sun Feb 14 2016 16:53:47.362  WARN   DWProtocolHandler   dwproto-0-9
>>    Timed out reading from CoCo in OP_WRITE
>>
>> Sun Feb 14 2016 16:53:47.367  WARN   DWProtocolHandler   dwproto-0-9
>>     OP_WRITE took 286ms.
>>

> This means the server is waiting for data from the CoCo and not getting it
> within the expected time period.  Some operations like writing involve a
> few back and forth exchanges between server and coco.  If either side takes
> longer than ~250ms iirc then the other side is supposed to assume failure,
> which is what the server is warning about.  It really shouldn't happen.
> So... first thing I'd check is the serial cable itself for anything loose,
> etc.  Some people have had this kind of result when the cable was just too
> long.  OP_WRITE is one of few times the coco actually sends a lot of bytes
> in a row over the wire so it can reveal a more general problem.

> Some usb-serial adapters have settings that cause some number of bytes to
> be queued up before they are delivered to the computer.  There is usually a
> timeout where even a single byte will eventually get delivered, but with
> just the wrong settings you could probably get this to happen even if all
> the bytes are transmitted perfectly by the coco.  That, or any other kind
> of serial port issue might be involved.  If you can verify the serial port
> and cabling works fine that would be a good thing to do.

Ugh.  I suppose it's possible that my trusty FTDI USB/Serial adapter has 
developed problems.

I'll go through all the hardware piece by piece and see if I can find the 
failure point.

Trying a lower data rate might be a good experiment as well.

Thanks for the information, Aaron.



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