C64 video output vs standard NTSC

[Ray Carlsen]

Can anyone tell me what the difference is between the video output
of a C64 or 128 and video signals from other sources? I bought a
StarTech AVLink comp2VGA converter that accepts all video sources and
displays them correctly, except for Commodore computers. I bought a Coby
15" LCD TV and it will not display a picture when connected to those
computers but works with any other video source: VCR, camera, old game
console, etc. Strangely enough, A VIC20 does work on that TV and with
the StarTech adapter.

Ray

[Andreas Meerbann]

> Can anyone tell me what the difference is between the video output
> of a C64 or 128 and video signals from other sources? I bought a

The output of the C64 (and many other home computers and video game consoles) is not adhering very much to any standard at all. Main difference is the fact that the C64 is generating a progressive signal whilst the NTSC standard demands an interlaced signal. To achieve this the C64 transmits only even (or odd? Don't remember) frames with a vertical resolution of 262 lines (288 in PAL) - The official standard demands consecutive even/odd frames with 262 and 263 lines resulting in the NTSC resolution of 525 lines for one full picture. I remember that there are other minor differences in the generation of the colour burst pulses but I would need to do some measurements to tell you the exact details of these standard deviations.
Some modern Displays are confused by such kind of signals because they try to sync up to an interlaced signal. Once they find one correct frame they try to sync up to the next which they expect to have its timing shifted by a half scan line. Since the C64 does not generate such kind of second frames the sync block constantly reports a sync error every second frame usually resulting in a picture mute. That's why modern TVs have problems with these signals.
There is not much you (as a "simple user") could do about it - just try to find the product that works for you and ignore the ones that don't.

[Payton Byrd]

Vizio TVs work great with C= equipment. Being an American company where there products are actually designed in America, they probably have more insight into what needs to be supported than some random Chinese company would.

[Ray Carlsen]

On 3/6/2013 3:42 AM, Andreas Meerbann wrote:
>> Can anyone tell me what the difference is between the video output
>> of a C64 or 128 and video signals from other sources?

> Main difference is the fact that the C64 is generating a progressive
> signal whilst the NTSC standard demands an interlaced signal.

<snip>

Thanks for the explanation, Andreas!

Ray

[Brendan Robert]

On Wednesday, March 6, 2013 7:24:28 AM UTC-6, Payton Byrd wrote:
> Vizio TVs work great with C= equipment. Being an American company where there products are actually designed in America, they probably have more insight into what needs to be supported than some random Chinese company would.

My LG TV seems to work with the standard composite signal just fine also.

-B

[rusure]

I have a random COBY 15.4" model TFTV 1524https://docs.google.com/file/d/0B80L9cEZ8YnvNlZvM2RIVnFabXM/edit?usp=sharing

[rusure]

See if I can get it right this time

On Tuesday, March 5, 2013 10:37:12 PM UTC-7, Ray Carlsen wrote:

I can plug the 128 composite AV output directly into my 15.4" COBY model TFTV 1524 AV ports. The video on the COBY looks like the composite video on a 1084 Commodore monitor. When I sold one of my RGB monitors, I wrote 3 programs to test the alighment of the monitor's RGB beams. The peograms can be used for generating test patterns. The program for RGB mode works perfectly running in 128 80 column mode. The programs for the 128 40 column mode and the one for the C64 are flaky. The RGB test pattern generator requires the RGB ML program first published in RUN magazine. I don't have the issue at my fingertips. The C64 program uses the graphics program named DGRAPH first published in the April 1988 issue of COMPUTE GAZETTE. I have uploaded the three programs to the following site:

https://docs.google.com/file/d/0B80L9cEZ8YnvNlZvM2RIVnFabXM/edit?usp=sharing

The programs requiring an ML module have them tacked onto the end of the BASIC graphics programs.

[Clocky]

Payton Byrd wrote:
> Vizio TVs work great with C= equipment. Being an American company where there products are actually designed in America, they probably have more insight into what needs to be supported than some random Chinese company would.
>

My cheap Chinese TV displays more formats than anything I've ever owned
before, and it displays them perfectly and likely uses the very same
components Vizio does given they produce a good percentage of them in
China.

[Groepaz]

where do you think does the decoder chip come from that is working inside
this "american" tv set?

--

http://www.hitmen-console.org http://magicdisk.untergrund.net
http://www.pokefinder.org http://ftp.pokefinder.org

Good artists copy, great artists steal.
<Pablo Picasso>

[Payton Byrd]

The decoder chip may very well be Chinese, but I would wager a bet that it was built to specs from Vizio.

[Groepaz]

Payton Byrd wrote:

> On Thursday, March 7, 2013 8:33:01 AM UTC-6, Groepaz wrote:
>> Payton Byrd wrote:
>>
>>
>>
>> > Vizio TVs work great with C= equipment. Being an American company
>> > where
>>
>> > there products are actually designed in America, they probably have
>> > more
>>
>> > insight into what needs to be supported than some random Chinese
>> > company
>>
>> > would.
>>
>>
>>
>> where do you think does the decoder chip come from that is working inside
>>
>> this "american" tv set?

>

> The decoder chip may very well be Chinese, but I would wager a bet that it
> was built to specs from Vizio.

you can be almost sure that they, like the entire industry, uses one of the
CDX decoderships from SONY. or an unlicensed chinese clone of it for that
matter.

"Vizio's major partner in the consumer electronics arena is AmTran
Technology, a Taiwan-based OEM/ODM that manufactures more than half of the
televisions sold by Vizio[3] and owns a 23% stake in the company.[3][4]
Vizio also manufactures its products in Mexico and China under agreements
with ODM assemblers in those countries."

its really just the same cheap asian stuff that you get from everyone else.
the display, the decoder, the powersupply. all standard off the shelve
chinese manufactured.

you can be lucky if the guys at vizio did actually "spec" anything at all.
perhaps the color of the case and the size of the box it ships in =P

--

http://www.hitmen-console.org http://magicdisk.untergrund.net
http://www.pokefinder.org http://ftp.pokefinder.org

When animal-rights activists and right-to-life protesters are marching
outside your laboratory, then you know you've definitely made progress in
your artificial life research.
<Donald A. Smith>

[rusure]

On Tuesday, March 5, 2013 10:37:12 PM UTC-7, Ray Carlsen wrote:

> Can anyone tell me what the difference is between the video output

> of a C64 or 128 and video signals from other sources? I bought a Coby

> 15" LCD TV and it will not display a picture when connected to those
> computers but works with any other video source: VCR, camera, old game
> console, etc. Strangely enough, A VIC20 does work on that TV and with
> the StarTech adapter.
>
> Ray

My COBY 15.4" model TFTV 1524 works perfectly with a C128D and
SX64. Do you have any of those on hand for experimenting?

[Clocky]

Groepaz wrote:
> Payton Byrd wrote:
>
>> On Thursday, March 7, 2013 8:33:01 AM UTC-6, Groepaz wrote:
>>> Payton Byrd wrote:
>>>
>>>
>>>
>>>> Vizio TVs work great with C= equipment. Being an American company
>>>> where
>>>
>>>> there products are actually designed in America, they probably have
>>>> more
>>>
>>>> insight into what needs to be supported than some random Chinese
>>>> company
>>>
>>>> would.
>>>
>>>
>>>
>>> where do you think does the decoder chip come from that is working inside
>>>
>>> this "american" tv set?
>
>>
>> The decoder chip may very well be Chinese, but I would wager a bet that it
>> was built to specs from Vizio.
>
> you can be almost sure that they, like the entire industry, uses one of the
> CDX decoderships from SONY. or an unlicensed chinese clone of it for that
> matter.
>

I doubt anyone uses Sony's chips as they are notorious for price gouging
on their custom logic.

> "Vizio's major partner in the consumer electronics arena is AmTran
> Technology, a Taiwan-based OEM/ODM that manufactures more than half of the
> televisions sold by Vizio[3] and owns a 23% stake in the company.[3][4]
> Vizio also manufactures its products in Mexico and China under agreements
> with ODM assemblers in those countries."
>
> its really just the same cheap asian stuff that you get from everyone else.
> the display, the decoder, the powersupply. all standard off the shelve
> chinese manufactured.
>
> you can be lucky if the guys at vizio did actually "spec" anything at all.
> perhaps the color of the case and the size of the box it ships in =P
>

I agree. If anything I would expect the multinationals to have a better
grasp of display compatibility as their market isn't just NTSC.

Anyway, IIRC the PAL signal the C64 puts out isn't clean either.

[Ray Carlsen]

Yes. I just tried it with my DCR and... nothing, "no signal". My Coby TV
is Model LEDTV1526 recently purchased from MCM Electronics. It surprised
me that it would not work with the Commodore since all my other LCD TV's
work fine, and I bought it as a small portable monitor specifically to
test those computers. Nuts!

Ray

[rusure]

On Tuesday, March 5, 2013 10:37:12 PM UTC-7, Ray Carlsen wrote:

> Can anyone tell me what the difference is between the video output

> of a C64 or 128 and video signals from other sources?. I bought a Coby

> 15" LCD TV and it will not display a picture when connected to those
> computers but works with any other video source: VCR, camera, old game
> console, etc. Strangely enough, A VIC20 does work on that TV and with
> the StarTech adapter.
>
> Ray

Have you tried adjusting the COBY's horizontal or vertical positions. Maybe your COBY thinks your C64 / C128's videos are somewhere in the Bermuda triangle. On my COBY, there is a SETUP menu. In there is an ADVANCED sub menue. The activation of the auto function fixed my VGA display headaches.

If worse comes to worse, your problematic Commodores' RF signals may need to be connected to the COAXIAL ports of your COBY or adapter.

[Ray Carlsen]

> On Tuesday, March 5, 2013 10:37:12 PM UTC-7, Ray Carlsen wrote:
>> Can anyone tell me what the difference is between the video output
>> of a C64 or 128 and video signals from other sources?. I bought a
>> Coby 15" LCD TV and it will not display a picture when connected
>> to those computers but works with any other video source: VCR,
>> camera, old game console, etc. Strangely enough, A VIC20 does work
>> on that TV and with the StarTech adapter.

> Have you tried adjusting the COBY's horizontal or vertical
> positions. Maybe your COBY thinks your C64 / C128's videos are
> somewhere in the Bermuda triangle. On my COBY, there is a SETUP
> menu. In there is an ADVANCED sub menue. The activation of the auto
> function fixed my VGA display headaches. If worse comes to worse,
> your problematic Commodores' RF signals may need to be connected to
> the COAXIAL ports of your COBY or adapter.

The PC adjustments you mentioned only work if you are running a VGA
computer input to the TV. This TV only has a simple menu, no advanced
settings possible. I did try the RF input as well, no luck. It just
doesn't like the progressive (as opposed to standard interlaced) video.

Ray