[Coco] serial port problem

Aaron Wolfe aawolfe at gmail.com
Fri Nov 1 00:09:03 EDT 2013


On Oct 31, 2013 11:56 PM, "Mathieu Bouchard" <matju at artengine.ca> wrote:
>
> Le 2013-10-31 à 22:51:00, Aaron Wolfe a écrit :
>
>
>> There are a wide variety of troubleshooting tools built into the
drivewire software.  These will provide much more accurate information than
tests with terminal programs will.  Before worrying about that, can you
double check that your cable matches this specification?
>>
>>
http://sourceforge.net/apps/mediawiki/drivewireserver/index.php?title=DriveWire_Specification#Physical_Interface_Requirements
>
>
> The cable+adaptor is 320 cm long, which is a tiny bit over the
recommended maximum length. Either terminal can use that cable as a
loopback using a paperclip (though my loopback test from the PC doesn't use
the adaptor). I describe this in my last mail to Tormod Volden this evening.
>
> I don't have a « Vcc » or « CD » wire in that cable : it has only three
wires. Is it really necessary ? The table only lists 3 pins to be used on
the DB9 side.
>
> I haven't connected the CD pin at all in the CoCo. I just tried doing so,
but it does not seem to make any difference.
>
> Now I noticed that regardless of whether the CD pin is plugged, doing a
DIR 0 (without DRIVE OFF) in HDB causes an UNKNOWN OPCODE 252 in DW. It
seems to be quite reproducible :
>
>   DIR 0   gives UNKNOWN OPCODE 252
>   DIR 1   gives UNKNOWN OPCODE 250
>   DIR 2   gives UNKNOWN OPCODE 249
>   DIR 3   gives UNKNOWN OPCODE 249
>   DIR 42  gives UNKNOWN OPCODE 24 then 237
>   DIR 128 gives UNKNOWN OPCODE 252
>   DIR 129 gives UNKNOWN OPCODE 250
>   DIR 130 gives UNKNOWN OPCODE 56 then 229
>   DIR 131 gives UNKNOWN OPCODE 56 then 229
>   DIR 170 gives UNKNOWN OPCODE 251

This is a baud rate mismatch, but other than that very promising, looks
like cable and physical ports are fine.

Make sure you are using the recommended ROMs, all of which are labeled
"dw3".  Anything labeled dw4 is experimental, requires special
configuration, and is very likely more trouble than its worth until
everything works perfectly with the stock Roms.

If you changed the baud rate from the default set by the goofy wizard, it
needs to remain at the default, which is 115200 for a coco 3.  I think its
more likely you just have the wrong ROM though.  That would cause exactly
what you are seeing.

>
> after « reset instance device » in DW, though, I don't get any messages
in DW until I restart DW.
>
>
>  ______________________________________________________________________
> | Mathieu BOUCHARD ----- téléphone : +1.514.383.3801 ----- Montréal, QC
>
>
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