[Coco] Weird CoCo3 problem...
Brian Blake
random_rodder at yahoo.com
Sat Jan 2 14:24:48 EST 2010
I used the same controller (FD-502) and same drives on all three CoCo's I tested.
________________________________
From: John Donaldson <johnadonaldson at sbcglobal.net>
To: CoCoList for Color Computer Enthusiasts <coco at maltedmedia.com>
Sent: Sat, January 2, 2010 2:23:03 PM
Subject: Re: [Coco] Weird CoCo3 problem...
Brian,
When you moved the drive, did you also move the controller? Also is
this one of the older controllers that requires 12VDC?
If you did not move the controller, there is the possibility that the
controller is bad.
John Donaldson
Brian Blake wrote:
> Hi Mike,
> The answer to both of those is 'yes'.
>
> I tried Tetris and it worked fine.
> I also tried the POKE on the CoCo3 with the C9 512k upgrade and the Drive 0 light did come on.
> --- On Sat, 1/2/10, Mike Pepe <lamune at doki-doki.net> wrote:
>
> From: Mike Pepe <lamune at doki-doki.net>
> Subject: Re: [Coco] Weird CoCo3 problem...
> To: "CoCoList for Color Computer Enthusiasts" <coco at maltedmedia.com>
> Date: Saturday, January 2, 2010, 2:10 AM
>
> 15KHz sounds about right for a loop like that. Every poke to that address should drive SCS low momentarily.
>
> Two other things come to mind for checking- if you put this controller/drive on another machine, does the poke make the drive activity light come on? Second thing is- do any other cartridges work on this machine? Any game paks to test with?
>
>
>
>> -----Original Message-----
>> From: coco-bounces at maltedmedia.com [mailto:coco-
>> bounces at maltedmedia.com] On Behalf Of Brian Blake
>> Sent: Friday, January 01, 2010 9:08 PM
>> To: CoCoList for Color Computer Enthusiasts
>> Subject: Re: [Coco] Weird CoCo3 problem...
>>
>> Hi Mike,
>>
>> Here's what I did - not sure if it was correct:
>>
>> 10 POKE &HFF40,1
>> 20 GOTO 10
>> RUN
>>
>> I then checked pin 6 of IC9 - which according to my schematic is the
>> /SCS line - HI reading on my DMM in logic mode (<1 = LO, >2 = HI, in
>> between it shows the voltage).
>> I then checked pin 40 on the 6809 - the /HALT line - and got a reading
>> of 1.545vdc.
>> Not sure if my DMM would react fast enough, I changed to Frequency mode
>> and checked pin 6 of IC9 again - got a reading of about 15-kHz.
>> I hit the break key and checked pin 6 again, and it was still HI.
>> Shut of the CoCo, waited a few seconds and turned it back on, checked
>> again and it was still HI.
>> Checking pin 36 on the slot yielded similar results, except the
>> frequency was very different ~110-kHz.
>>
>>
>>
>> ________________________________
>> From: Mike Pepe <lamune at doki-doki.net>
>> To: CoCoList for Color Computer Enthusiasts <coco at maltedmedia.com>
>> Sent: Fri, January 1, 2010 9:45:14 PM
>> Subject: Re: [Coco] Weird CoCo3 problem...
>>
>> I'd put that POKE &HFF40,1 into an endless loop and look to see if the
>> SCS line on the cartridge port is stuck high or if it pulsates.
>>
>> Radio Shack used to sell a pretty decent logic probe for about $20. Not
>> sure if they still do, but it would help diagnose the problem in this
>> case.
>>
>> The latch at $FF40 should function independently of a blown out 6809
>> HALT line which is what usually indicates a CPU replacement.
>>
>>
>>> -----Original Message-----
>>> From: coco-bounces at maltedmedia.com [mailto:coco-
>>> bounces at maltedmedia.com] On Behalf Of Brian Blake
>>> Sent: Friday, January 01, 2010 4:48 PM
>>> To: CoCoList for Color Computer Enthusiasts
>>> Subject: Re: [Coco] Weird CoCo3 problem...
>>>
>>> Nope - no logic probe. What kind of signal should be seen there? My
>>>
>> DMM
>>
>>> has some logic functions built into it, but, I'm not sure off hand
>>>
>> what
>>
>>> it's capable of...
>>>
>>>
>>>
>>> ________________________________
>>> From: Mike Pepe <lamune at doki-doki.net>
>>> To: CoCoList for Color Computer Enthusiasts <coco at maltedmedia.com>
>>> Sent: Fri, January 1, 2010 7:39:58 PM
>>> Subject: Re: [Coco] Weird CoCo3 problem...
>>>
>>> That's pretty strange. If you have a logic probe you can do some more
>>> investigation. The LS138 chip may be faulty.
>>>
>>>
>>>> -----Original Message-----
>>>> From: coco-bounces at maltedmedia.com [mailto:coco-
>>>> bounces at maltedmedia.com] Ong happens accept an I/O error - not
>>>>
>> light,
>>
>>> no
>>>
>>>> disk activity, nothing...
>>>>
>>>> Behalf Of Brian Blake
>>>> Sent: Friday, January 01, 2010 3:24 PM
>>>> To: CoCoList for Color Computer Enthusiasts
>>>> Subject: Re: [Coco] Weird CoCo3 problem...
>>>>
>>>> Tried the POKE and no drive activity light came on. Anytime I try
>>>>
>> to
>>
>>>> access the disk, nothin
>>>>
>>>> ________________________________
>>>> From: Mike Pepe <lamune at doki-doki.net>
>>>> To: CoCoList for Color Computer Enthusiasts <coco at maltedmedia.com>
>>>> Sent: Fri, January 1, 2010 6:08:28 PM
>>>> Subject: Re: [Coco] Weird CoCo3 problem...
>>>>
>>>> I suspect the 6809 as well. But if you do a poke &HFF40,1 the drive
>>>>
>> 1
>>
>>>> activity light should go on. If not something else may be wrong.
>>>>
>>>>
>>>>> -----Original Message-----
>>>>> From: coco-bounces at maltedmedia.com [mailto:coco-
>>>>> bounces at maltedmedia.com] On Behalf Of Brian Blake
>>>>> Sent: Friday, January 01, 2010 2:36 PM
>>>>> To: CoCoList for Color Computer Enthusiasts
>>>>> Subject: Re: [Coco] Weird CoCo3 problem...
>>>>>
>>>>> Hi Arthur,
>>>>>
>>>>> Unfortunately, it's not socketed. Tho, I have about 9 6309's and
>>>>>
>>>> plenty
>>>>
>>>>> of sockets... hmmmm.... maybe tomorrow....
>>>>>
>>>>>
>>>>>
>>>>> ________________________________
>>>>> From: Arthur Flexser <flexser at fiu.edu>
>>>>> To: CoCoList for Color Computer Enthusiasts
>>>>>
>> <coco at maltedmedia.com>
>>
>>>>> Sent: Fri, January 1, 2010 3:56:15 PM
>>>>> Subject: Re: [Coco] Weird CoCo3 problem...
>>>>>
>>>>> I vaguely recall something like this happening to me years ago
>>>>>
>> that
>>
>>>> was
>>>>
>>>>> fixed by replacing the 6809. If this machine and one of your
>>>>>
>>> others
>>>
>>>>> has had
>>>>> the 6809 socketed, it would be easy enough to swap in a 6809 from
>>>>>
>>> one
>>>
>>>>> of the
>>>>> other machines and see if the problem goes away.
>>>>>
>>>>> Art
>>>>>
>>>>> On 1/1/10, Brian Blake <random_rodder at yahoo.com> wrote:
>>>>>
>>>>>>
>>>>>> All of these new developments on the CoCo front finally lit the
>>>>>>
>>>> fire
>>>>
>>>>> under
>>>>>
>>>>>> my arse to set up real hardware again. Besides my repack
>>>>>>
>> project,
>>
>>> I
>>>
>>>>> have 3
>>>>>
>>>>>> other CoCo3's, two with 512k upgrades (one C9 and one PBJ) and
>>>>>>
>>> one
>>>
>>>>> 128k. The
>>>>>
>>>>>> one with the C9 upgrade works fine - can load and play
>>>>>>
>>> Sockmaster's
>>>
>>>>> Donkey
>>>>>
>>>>>> Kong.
>>>>>>
>>>>>> The one with the PBJ upgrade, not so... At boot, it comes up as
>>>>>>
>>> it
>>>
>>>>> should
>>>>>
>>>>>> with the proper display. However, any floppy commands are met
>>>>>>
>>> with
>>>
>>>> no
>>>>
>>>>>> response from the floppy drive (with an FD-502 controller) at
>>>>>>
>>> all.
>>>
>>>>> Almost
>>>>>
>>>>>> like the drive is off. The drive responds as it should in the
>>>>>>
>>> other
>>>
>>>>> two
>>>>>
>>>>>> machines. Upon removing the top case and k/b, I saw two wires,
>>>>>>
>>> each
>>>
>>>>> had been
>>>>>
>>>>>> soldered to opposite sides of R23. Now, under the keyboard, is
>>>>>>
>>>>> another wire
>>>>>
>>>>>> with alligator clips on each end, and the clips are holding on
>>>>>>
>> to
>>
>>>> the
>>>>
>>>>> bare
>>>>>
>>>>>> end of the wires soldered to R23, effectively bypassing the
>>>>>>
>>>> resistor.
>>>>
>>>>> I'm
>>>>>
>>>>>> looking for the PBJ instructions, pretty sure I have them, to
>>>>>>
>>> find
>>>
>>>>> out if
>>>>>
>>>>>> this is called for. I can also see where C65 & C66 have been
>>>>>>
>> cut
>>
>>>> and
>>>>
>>>>>> re-soldered. I have reseated the GIME and the PBJ memory chips,
>>>>>>
>>> and
>>>
>>>>> cleaned
>>>>>
>>>>>> the 40 pin connector.
>>>>>>
>>>>>> Any other suggestions? My 100MHz o'scope bit the dust so I
>>>>>>
>> don't
>>
>>>> have
>>>>
>>>>> that
>>>>>
>>>>>> tool any more (anybody have a CRT for a Leader 3 channel 100MHz
>>>>>>
>>>>> scope??)
>>>>>
>>>>>> Thanks,
>>>>>>
>>>>>> Brian
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> --
>>>>>> Coco mailing list
>>>>>> Coco at maltedmedia.com
>>>>>> http://five.pairlist.net/mailman/listinfo/coco
>>>>>>
>>>>>>
>>>>> --
>>>>> Coco mailing list
>>>>> Coco at maltedmedia.com
>>>>> http://five.pairlist.net/mailman/listinfo/coco
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> --
>>>>> Coco mailing list
>>>>> Coco at maltedmedia.com
>>>>> http://five.pairlist.net/mailman/listinfo/coco
>>>>>
>>>> --
>>>> Coco mailing list
>>>> Coco at maltedmedia.com
>>>> http://five.pairlist.net/mailman/listinfo/coco
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> --
>>>> Coco mailing list
>>>> Coco at maltedmedia.com
>>>> http://five.pairlist.net/mailman/listinfo/coco
>>>>
>>> --
>>> Coco mailing list
>>> Coco at maltedmedia.com
>>> http://five.pairlist.net/mailman/listinfo/coco
>>>
>>>
>>>
>>>
>>>
>>> --
>>> Coco mailing list
>>> Coco at maltedmedia.com
>>> http://five.pairlist.net/mailman/listinfo/coco
>>>
>> --
>> Coco mailing list
>> Coco at maltedmedia.com
>> http://five.pairlist.net/mailman/listinfo/coco
>>
>>
>>
>>
>>
>> --
>> Coco mailing list
>> Coco at maltedmedia.com
>> http://five.pairlist.net/mailman/listinfo/coco
>>
>
>
> --
> Coco mailing list
> Coco at maltedmedia.com
> http://five.pairlist.net/mailman/listinfo/coco
>
>
>
>
>
> --
> Coco mailing list
> Coco at maltedmedia.com
> http://five.pairlist.net/mailman/listinfo/coco
>
>
--
--
Coco mailing list
Coco at maltedmedia.com
http://five.pairlist.net/mailman/listinfo/coco
More information about the Coco
mailing list