[Coco] video composite on korean coco 26-3134A
Zippster
zippster278 at gmail.com
Sat Oct 4 09:13:00 EDT 2014
Hmm…,
I have a 26-3134 (no “A”), a 26-3136, and a 26-3028.
On all of them the label on the machine says 120v - 60hz.
Is this a NTSC CoCo for the North American market?
Do you hear a relay click when you switch on the machine?
-Ed
On Oct 4, 2014, at 12:59 AM, didier derny <didier at aida.org> wrote:
> I tried, I was not expecting a correct image, but at least something like a
> synchro
> But nothing, just snow...
>
> The tv see a "VCR" but no signal
>
> Any idea if the modulator or the coco uses the 60hz ?
> The power supply is 110v but 50Hz
>
> That's why I have a serious doubt about this machine...
>
> --
> didier
>
> -----Message d'origine-----
> De : Coco [mailto:coco-bounces at maltedmedia.com] De la part de Zippster
> Envoyé : samedi 4 octobre 2014 00:17
> À : CoCoList for Color Computer Enthusiasts
> Objet : Re: [Coco] video composite on korean coco 26-3134A
>
> You could rig up a quick and dirty piece of coax cable from the RF port to
> the antenna in jack on a tv and tune it to channel 3 or 4 (whatever the
> switch is on). The picture may not even be that bad.
>
> Or the relay.
>
>
> -Ed
>
>
> On Oct 3, 2014, at 4:30 PM, Chris <coronet1969 at gmail.com> wrote:
>
>> type CLOAD and listen for the relay.
>>
>> On Fri, Oct 3, 2014 at 3:29 PM, Zippster <zippster278 at gmail.com> wrote:
>>
>>> Check for a clock signal and address/data line activity at the cpu.
>>>
>>> -Ed
>>>
>>>
>>> On Oct 3, 2014, at 2:16 PM, didier derny <didier at aida.org> wrote:
>>>
>>>> I'll probably order a pcb
>>>>
>>>> My main problem, is that I have absolutely no idea if the coco 2 is
>>> working
>>>> at all
>>>> I tested inside the modulator but I've not seen any signal looking
>>>> like a video signal (no synchro seen)
>>>>
>>>> Is there any other way to know if it is dead or alive ?
>>>>
>>>> --
>>>> didier
>>>>
>>>>
>>>> -----Message d'origine-----
>>>> De : Coco [mailto:coco-bounces at maltedmedia.com] De la part de
>>>> Zippster Envoyé : vendredi 3 octobre 2014 19:21 À : CoCoList for
>>>> Color Computer Enthusiasts Objet : Re: [Coco] video composite on
>>>> korean coco 26-3134A
>>>>
>>>> Mike,
>>>>
>>>> I made this board to replace the RF modulator box that was in my
>>>> Korean CoCo2.
>>>> I removed the modulator, and soldered pin headers in where the
>>>> inputs to
>>> the
>>>> modulator are. Y, øA, øB, CHB, CLK, Sound, and +5v are all in these
>>>> headers.
>>>> The area underneath the modulator is pretty much all ground plane,
>>> allowing
>>>> me to drill mounting holes for the board, and use standoffs to attach
> it.
>>>>
>>>> Corresponding female headers on the board then just plug into the
>>>> motherboard (except for
>>>> 1 ground wire that needs to be attached). Then I made a cutout in
>>>> the
>>> back
>>>> of the CoCo case, basically expanding where the RF connector was.
>>>> It
>>> makes
>>>> for a pretty neat installation.
>>>> (I’ll put some more pics up later).
>>>>
>>>> I’m not sure if all Korean CoCo2 main boards have the same layout in
>>>> the modulator area, but I think we may have the same model, so it
>>>> should
>>> fit.
>>>>
>>>> I know other CC2’s have differing layouts for the modulator area,
>>>> but
>>> it’s
>>>> easy enough to lay out a board to fit those (with measurements).
>>>>
>>>> I had also thought of the idea of a board plugging into the MC6847
>>> socket,
>>>> and moving it to onto the board, which is a good one. I’m planing
>>>> on
>>> this
>>>> approach for a Component Video board I’m working on. It would be
>>>> pretty easy to socket non-socketed 6847’s if you’re willing to
>>>> sacrifice the
>>> chip
>>>> (utsource has them, I think I paid $5ea for five).
>>>>
>>>> - Ed
>>>>
>>>>
>>>>
>>>> On Oct 3, 2014, at 11:17 AM, mike at borncoco.com wrote:
>>>>
>>>>> Ed, I ordered some of your boards from OSHpark. Nice layout! I'll
>>>>> have
>>> to
>>>> open up a Korean CoCo 2 this weekend to see how you made the
>>>> connections
>>> to
>>>> the motherboard. Any info on what you must remove? If you already
>>> discussed
>>>> this here, just say so and I'll look in the archives later. As you
>>>> said,
>>> it
>>>> would not be difficult to use clip leads to make the connections for
>>>> any CoCo2. I am still interested in creating a version that can be
>>>> plugged
>>> into
>>>> the 6847 socket. I know the other puzzle is that some models of the
>>>> CoCo
>>> 2
>>>> have the RF modulator box mounted in different ways - some at 90
>>>> degrees
>>> to
>>>> the motherboard.
>>>>>
>>>>> Great work on the board and I appreciate the time and effort you
>>>>> put
>>> into
>>>> this and sharing it with all of us! I look forward to assembling the
>>> boards
>>>> when they arrive.
>>>>>
>>>>> Cheers,
>>>>> -Mike
>>>>>
>>>>> -----Original Message-----
>>>>> From: "Zippster" <zippster278 at gmail.com>
>>>>> Sent: Friday, October 3, 2014 11:53am
>>>>> To: "CoCoList for Color Computer Enthusiasts"
>>>>> <coco at maltedmedia.com>
>>>>> Subject: Re: [Coco] video composite on korean coco 26-3134A
>>>>>
>>>>> There was when it was sent, not sure what’s stripping them out.
>>>>>
>>>>> I’ll list them this way…
>>>>>
>>>>> https://sites.google.com/site/thezippsterzone/home/coco2-projects
>>>>>
>>>>> https://oshpark.com/shared_projects/lHtMJ67Z
>>>>>
>>>>> -Ed
>>>>>
>>>>>
>>>>> On Oct 3, 2014, at 10:48 AM, Al Hartman <alhartman6 at optonline.net>
>>> wrote:
>>>>>
>>>>>> There's no link in that message...
>>>>>>
>>>>>> -[ Al ]-
>>>>>>
>>>>>> -----Original Message----- From: Zippster
>>>>>> Sent: Friday, October 03, 2014 10:34 AM
>>>>>> To: CoCoList for Color Computer Enthusiasts
>>>>>> Subject: Re: [Coco] video composite on korean coco 26-3134A
>>>>>>
>>>>>> Hey guys,
>>>>>>
>>>>>> You may have missed my earlier post. I did a version of this
>>>>>> circuit
>>> in
>>>> Eagle.
>>>>>> Sound output is included.
>>>>>>
>>>>>> The files are in the zip on this page. CoCo2 Projects (Tandy
>>>>>> Color Computer 2) - The Zippster Zone
>>>>>>
>>>>>> I put it up as a shared project on OSHPark. OSH Park ~ Coco2
>>>>>> Composite Out (Type 01) Rev 03
>>>>>>
>>>>>> I laid the board out to replace the RF modulator in my Korean
>>>>>> CoCo2’s, but as long as you get the signals to it, you could mount
>>>>>> it
>>>> anywhere.
>>>>>>
>>>>>> -Ed
>>>>>>
>>>>>>
>>>>>> On Oct 3, 2014, at 7:20 AM, Michael Rowen <mike at borncoco.com> wrote:
>>>>>>
>>>>>>> John is indeed correct. I have built the simple circuit that
>>>>>>> includes
>>> a
>>>> 1372 that connects to the signal from the 6847. It works well on
>>>> every monitor I've used with a CoCo 2. The circuit is in the data
>>>> sheet for the 6847. I have not had the time to create a PCB with
>>>> Eagle. Some CoCos have the 6847 socketed, so it would be easy to
>>>> make a board that plugs into
>>> that
>>>> 40 pin socket, with the 6847 plugging into the board. CoCo 2s with a
>>>> soldered 6847, would require 7-8 clip leads, but can be done. I have
>>> bread
>>>> boarded this on a CoCo 2. This was the same method used by the
>>>> Colorware adapter. I scored one of these at last year's CoCo fest.
>>>> Its circuit uses more caps, but the principle is the same. I have
>>>> not found any
>>> significant
>>>> quality differences using the reference circuit. Clean and sharp.
>>>> Any
>>> Eagle
>>>> experts with some time on their hands to create the PCB files?? :)
>>>> It
>>> will
>>>> probably be Christmas time before I get the chunk of time to tackle
> this.
>>>> I'm a newbie with Eaglecad. I'll try to post a video this weekend.
>>>>>>>
>>>>>>> Cheers,
>>>>>>> Mike Rowen
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> "John W. Linville" <linville at tuxdriver.com> wrote:
>>>>>>>
>>>>>>>> NTSC CoCo2's use a modulator that does _not_ take a composite
>>>>>>>> video input.
>>>>>>>>
>>>>>>>> The 6847 outputs signals called Y, phiA, and phiB. These are
>>>>>>>> (very) roughly analogous to the YIQ signals that form a
>>>>>>>> composite
>>> video
>>>> signal.
>>>>>>>> A Motorola 1372 chip is used to combine those signals into
>>>>>>>> something useful. The 1372 chip can produce either a baseband
>>>>>>>> composite video signal or (by use of an RF tank circuit) a
>>>> TV-compatible radio signal.
>>>>>>>>
>>>>>>>> On the Coco1, the 1372 only produced a composite video signal
>>>>>>>> that was then fed (along with the audio signal) to an off the
>>>>>>>> shelf RF modulator. On the CoCo2, the 1372 chip is only
>>>>>>>> included as part of the RF modulator itself. The Y, phiA, and
>>>>>>>> phiB signals go straight to the modulator where the RF-equipped
>>>>>>>> 1372 turns them into a TV
>>>> signal.
>>>>>>>>
>>>>>>>> I'm not sure if there is a pristine composite video signal
>>>>>>>> available anywhere inside the RF modulator on a CoCo2. I was
>>>>>>>> never able to find one, FWIW. You probably need to pull the
>>>>>>>> modulator and build a new 1372-based circuit to replace it.
>>>>>>>>
>>>>>>>> Good luck!
>>>>>>>>
>>>>>>>> John
>>>>>>>>
>>>>>>>> P.S. It sounds like the PAL CoCo2 might be designed more like
>>>>>>>> the
>>>>>>>> CoCo1 in this regard. Of course, that only helps you if you are
>>>>>>>> using a PAL CoCo2... :-)
>>>>>>>>
>>>>>>>> On Thu, Oct 02, 2014 at 09:56:31PM +0200, didier derny wrote:
>>>>>>>>> Hi,
>>>>>>>>>
>>>>>>>>> I tried but no success...
>>>>>>>>>
>>>>>>>>> I don’t have any image on tv (connected to the antenna) No idea
>>>>>>>>> if the coco 2 is broken or if my tv is unable to process the
>>>>>>>>> signal
>>>>>>>>>
>>>>>>>>> With the oscilloscope I've not been a able to find a composite
>>>>>>>>> signal Inside the modulator...
>>>>>>>>>
>>>>>>>>> Any idea ?
>>>>>>>>>
>>>>>>>>> Thanks
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> --
>>>>>>>>> didier
>>>>>>>>>
>>>>>>>>> -----Message d'origine-----
>>>>>>>>> De : Coco [mailto:coco-bounces at maltedmedia.com] De la part de
>>>>>>>>> Simon Jonassen Envoyé : samedi 27 septembre 2014 16:26 À :
>>>>>>>>> 'CoCoList for Color Computer Enthusiasts'
>>>>>>>>> Objet : Re: [Coco] video composite on korean coco 26-3134A
>>>>>>>>>
>>>>>>>>> Hey....
>>>>>>>>>
>>>>>>>>> I did mine by tapping into the feeds that go directly to the rf
>>>>>>>>> modulator....
>>>>>>>>>
>>>>>>>>> A couple of shielded wires soldered on to the pins and 2 rca
>>>>>>>>> jacks on the rear of the case (audio/video)
>>>>>>>>>
>>>>>>>>> Works fine... No extra components needed (PAL machine)...
>>>>>>>>>
>>>>>>>>> /Simon :-)
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> -----Oprindelig meddelelse-----
>>>>>>>>> Fra: Coco [mailto:coco-bounces at maltedmedia.com] På vegne af
>>>>>>>>> didier derny
>>>>>>>>> Sendt: 27. september 2014 13:23
>>>>>>>>> Til: 'CoCoList for Color Computer Enthusiasts'
>>>>>>>>> Emne: [Coco] video composite on korean coco 26-3134A
>>>>>>>>>
>>>>>>>>> Hi
>>>>>>>>>
>>>>>>>>> Is there an easy way to get a video composite signal on this
>>> machine ?
>>>>>>>>>
>>>>>>>>> I guess a video composite signal or something approaching
>>>>>>>>> should be found Somewhere near the modulator or inside the
> modulator ?
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> Thanks
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> --
>>>>>>>>> Coco mailing list
>>>>>>>>> Coco at maltedmedia.com
>>>>>>>>> https://pairlist5.pair.net/mailman/listinfo/coco
>>>>>>>>> -----
>>>>>>>>> Ingen virus fundet i denne meddelelse.
>>>>>>>>> Kontrolleret af AVG - www.avg.com
>>>>>>>>> Version: 2012.0.2247 / Virusdatabase: 4031/7782 - Udgivelsesdato:
>>>>>>>>> 27-09-2014
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> --
>>>>>>>>> Coco mailing list
>>>>>>>>> Coco at maltedmedia.com
>>>>>>>>> https://pairlist5.pair.net/mailman/listinfo/coco
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> --
>>>>>>>>> Coco mailing list
>>>>>>>>> Coco at maltedmedia.com
>>>>>>>>> https://pairlist5.pair.net/mailman/listinfo/coco
>>>>>>>>>
>>>>>>>>
>>>>>>>> --
>>>>>>>> John W. Linville Someday the world will need a hero, and you
>>>>>>>> linville at tuxdriver.com might be all we have. Be ready.
>>>>>>>>
>>>>>>>> --
>>>>>>>> Coco mailing list
>>>>>>>> Coco at maltedmedia.com
>>>>>>>> https://pairlist5.pair.net/mailman/listinfo/coco
>>>>>>>
>>>>>>> --
>>>>>>> Coco mailing list
>>>>>>> Coco at maltedmedia.com
>>>>>>> https://pairlist5.pair.net/mailman/listinfo/coco
>>>>>>
>>>>>>
>>>>>> --
>>>>>> Coco mailing list
>>>>>> Coco at maltedmedia.com
>>>>>> https://pairlist5.pair.net/mailman/listinfo/coco
>>>>>>
>>>>>> --
>>>>>> Coco mailing list
>>>>>> Coco at maltedmedia.com
>>>>>> https://pairlist5.pair.net/mailman/listinfo/coco
>>>>>
>>>>>
>>>>> --
>>>>> Coco mailing list
>>>>> Coco at maltedmedia.com
>>>>> https://pairlist5.pair.net/mailman/listinfo/coco
>>>>>
>>>>>
>>>>>
>>>>> --
>>>>> Coco mailing list
>>>>> Coco at maltedmedia.com
>>>>> https://pairlist5.pair.net/mailman/listinfo/coco
>>>>
>>>>
>>>> --
>>>> Coco mailing list
>>>> Coco at maltedmedia.com
>>>> https://pairlist5.pair.net/mailman/listinfo/coco
>>>>
>>>>
>>>> --
>>>> Coco mailing list
>>>> Coco at maltedmedia.com
>>>> https://pairlist5.pair.net/mailman/listinfo/coco
>>>
>>>
>>> --
>>> Coco mailing list
>>> Coco at maltedmedia.com
>>> https://pairlist5.pair.net/mailman/listinfo/coco
>>>
>>
>> --
>> Coco mailing list
>> Coco at maltedmedia.com
>> https://pairlist5.pair.net/mailman/listinfo/coco
>
>
> --
> Coco mailing list
> Coco at maltedmedia.com
> https://pairlist5.pair.net/mailman/listinfo/coco
>
>
> --
> Coco mailing list
> Coco at maltedmedia.com
> https://pairlist5.pair.net/mailman/listinfo/coco
More information about the Coco
mailing list