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The Commodore 64 appears to be the second computer to offer native Y/C


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My first computer was the Coleco ADAM computer in October of 1983. It had a Zilog Z80 3.58Mhz CPU which was more powerful when compared to the January 1985 Commodore 128 Z80 2Mhz CPU. However, the Commodore Amiga 500 which was released in July 1985 was more powerful when compared to the Coleco ADAM computer system (The Coleco ADAM ended up being discontinued back in January of 1985).

I am discovering that every 8 bit computer has its plusses and minuses. The Commodore 128 had a better quality 80 column video output when compared to the Coleco ADAM video output plus the Commodore 128 offered native Y/C output which bypasses the TV/Monitors combo filter. When the Commodore 64 first came out in August 1982 the first motherboards only offered composite video output by a 5 pin DIN jack. However, in the Spring of 1983 the 250407 Commodore 64 motherboards had a 8 pin DIN connector with true Y/C output when connected to a special computer monitor. The November 1979 ATARI 800 was the first computer with Y/C output. The better quality S-Video jack with luminance and chrominance separated was not designed until 1987 and then in the late 1987 new TV/Monitors started appearing on the market with S-Video. However, around the year 2010+ S-Video was dropped from all new TV/Monitors being manufactured in retail stores. It is too bad S-Video is no longer offered on new models of TV/Monitors since that was the best quality video output offered for the Commodore 64 and 128 computers. I guess some people in the 21st Century might be internally modifying their Commodore 64 and 128 computers to have native HDMI, VGA, and component video output which is even better than S-Video.

Edited by HDTV1080P
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As far as I understand it, the VIC-II chip basically generates Y/C signals natively, and the internal color palette is stored in that sort of form. There's nowhere on the motherboard, nor even inside the VIC-II chip itself, that you can tap into RGB. The best you're going to get from the hardware is Y/C.

 

Even if modern TVs had S-Video inputs, they'd still be internal digital conversions & upscales to native resolution. So using an external device to encode to HDMI would generally yield similar or better quality than TV-native S-Video, though maybe also adding latency.

 

The C64 cartridges & replacement motherboards which output VGA and HDMI contain their own FPGA recreation of a fully RGB VIC-II, and aren't using any video source from inside the C64.

Edited by White Flame
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There seems to be several explanations what the S in S-Video really stands for. Wikipedia says Separate, others say Super, yet others say Sony. As far as I understand, the latter comes from the Sony Betacam launched in August 1982. It stores luminance on one track and chrominance on another track with alternating segments of R-Y and B-Y. However as noted the Atari 800 predates both the C64 and Betacam by three years, so Y/C must've been used elsewhere before that, just that perhaps it wasn't called S-Video until much later.

 

Of course Georges Valensi patented Y/C video already back in 1938, so perhaps it should be called GV-Video? :)

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My first computer was the Coleco ADAM computer in October of 1983. It had a Zilog Z80 3.58Mhz CPU which was more powerful when compared to the January 1985 Commodore 128 Z80 2Mhz CPU. However, the Commodore Amiga 500 which was released in July 1985 was more powerful when compared to the Coleco ADAM computer system (The Coleco ADAM ended up being discontinued back in January of 1985).

I am discovering that every 8 bit computer has its plusses and minuses. The Commodore 128 had a better quality 80 column video output when compared to the Coleco ADAM video output plus the Commodore 128 offered native Y/C output which bypasses the TV/Monitors combo filter. When the Commodore 64 first came out in August 1982 the first motherboards only offered composite video output by a 5 pin DIN jack. However, in the Spring of 1983 the 250407 Commodore 64 motherboards had a 8 pin DIN connector with true Y/C output when connected to a special computer monitor. The November 1979 ATARI 800 was the first computer with Y/C output. The better quality S-Video jack with luminance and chrominance separated was not designed until 1987 and then in the late 1987 new TV/Monitors started appearing on the market with S-Video. However, around the year 2010+ S-Video was dropped from all new TV/Monitors being manufactured in retail stores. It is too bad S-Video is no longer offered on new models of TV/Monitors since that was the best quality video output offered for the Commodore 64 and 128 computers. I guess some people in the 21st Century might be internally modifying their Commodore 64 and 128 computers to have native HDMI, VGA, and component video output which is even better than S-Video.

 

 

This is incorrect, neither the Atari 800 nor the 800XL offered Y/C video. They only offered composite or Luma (monochrome) on the video port. The idea being you would hook to either a composite monitor, or a monochrome monitor.

 

Atari never hooked up the Chroma signal to their video port until the XE-series in 1985.

 

So Commodore was the first to offer it to the mass market, and this also explains why no Y/C monitors appeared for Atari in the 3 year period between when the 800 was released and the C64 was released.

 

Also, this is a topic for another thread, but the 2mhz 8502 in the C128 would clean the clock of a 3.58mhz Z/80 :-)

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The original ATARI 800 from Nov 1979 has a 5 pin DIN jack that has Y/C output and with the proper cable can be connected to a old pre 2010 TV with S-Video. The 800XL did not start offering Y/C until after August of 1984. The Atari 65XE and 130XE offer Y/C output.

 

Therefore the ATARI 800 offered Y/C output 4 years before the Commodore 64 started offering the feature. However the Commodore 64 and Commodore 128 are clearly more powerful computers when compared to the ATARI computer. I prefer my ADAM computer over the Commodroe 64, however there are some nice advanced features like 80 column color on the Commodore 128 that outperform the Coleco ADAM computer in those areas.

Edited by HDTV1080P
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This is incorrect, neither the Atari 800 nor the 800XL offered Y/C video. They only offered composite or Luma (monochrome) on the video port. The idea being you would hook to either a composite monitor, or a monochrome monitor.

 

Atari never hooked up the Chroma signal to their video port until the XE-series in 1985.

 

 

That is demonstrably incorrect. The Atari 800 sitting less that 10 feet away from me is connected (ironically) to a Commodore 1702 monitor using separate chroma and luma.

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Correct. I wonder why they removed it from the XL.

That is a good question. Perhaps only 1% of ATARI 800 owners were using the Y/C feature and maybe for cost cutting reasons when the ATARI 800XL first came out it was not wired for Y/C. However starting in August of 1984 all ATARI 800XL's were being manufactured with the Y/C output active on the 5 pin DIN jack.

 

In the years between 1987 to 2010 there were many higher end TV/monitors that offered the S-Video feature that both ATARI and Commodore computer owners took advantage of to get the best picture in the 80's and 90's. However around the year 2018 many people internally modify their classic 80's computers now so that they have HDMI output which is much better then S-Video. But ATARI and Commodore will go down in history as the first two computer companies that used native Y/C output. I would have to research to make sure but I believe that there was some videogame systems in the late 80's or early 90's that used native S-Video and possible native component video which is better then S-Video. Around 1997 soon after the DVD format launched 480i component video jacks became the high-end video connection that would replace S-Video. By the year 2010 480i or 1080i component jacks along with HDMI replaced the S-Video jacks on all TV's. Now HDMI is rapidly replacing component video on most TV and on all computer monitors. Also in the early 21st 1080i component video was used on HDTV's. Some videogame systems most likely have native component video hookups. Possible some 16 bit and 32 bit videogame systems.

Edited by HDTV1080P
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There seems to be several explanations what the S in S-Video really stands for. Wikipedia says Separate, others say Super, yet others say Sony.

 

"S-Video" as a term definitely stands for "Super Video". It comes from S-VHS, which stands for "Super-Video Home System". And it refers specifically to the 4 pin mini-DIN connector developed in 1987 (the same year S-VHS was developed, which is what that connector was developed for).

 

Separate Y/C video has been around for a lot longer than the term "S-Video" or the 4 pin mini-DIN connector has been in use, obviously. But nobody called it "S-Video" before 1987, because that particular standard didn't exist yet. You can do an experiment yourself and search for the term "S-Video" in Google Groups, which includes most of the original Usenet from the 80's and before, using the "before:" date modifier. There's not a single mention of it before 1989. And all of the mentions in 1989 are either about S-VHS or the 4 pin mini-DIN connector.

 

Interestingly, there's a guy in one of those 1989 posts who defines a bunch of video terms, and one of them is S-Video:

 

 

 

S-video, S-connector, YC3.58, YC4.43. An interface which conveys

luminance, and quadrature modulated chrominance, as two separate signals

on a specific 4-pin mini-DIN connector.

 

So he doesn't say specifically what the "S" stands for, but he does say it's specific to the connector introduced in 1987.

 

As someone who grew up knowing this (I sold electronics for a living just after high school), I was always really confused when I started seeing people use the term "S-Video" to refer to Y/C video generally, regardless of connector. If somebody told me a monitor had "S-Video", to me that meant it had the 4 pin mini-DIN connector. I still get tripped up by this sometimes but I've learned to ask people to clarify what they mean. It can mean the difference between buying an off the shelf cable or having to make one myself, sometimes using connectors that are borderline impossible to find.

 

I'm not sure what the most common term for Y/C video was before the S-Video standard came about... probably just Y/C video. I see people using the terms accurately in this thread, though, which is kind of refreshing (and not the norm these days, in my experience).

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Perhaps only 1% of ATARI 800 owners were using the Y/C feature

 

The same hold true for c64 owners I knew including myself. But I recall that I got a very good picture using the RF cable on my Sanyo TV set.

 

Only 1 person of all the people I knew had a monitor to take advantage of this. I wonder why Commodore left it in.

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every one I have seen back in the day with a commodore monitor used the yc connections, and I worked with a lot of them back then

 

its like you paid almost as much for the screen as you did for the computer might as well use the good stuff right

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