60 vs. 50 Hz doesn't matter.
110 vs. 230 Volt does - most likely you would also need a transformer.

When I was using my A1200 in the UK on a 1024S monitor, I could switch it to NTSC mode and adjust the vertical hold to synch the picture. This was only helpful in one or two games that had messed up aspect ratio, or seemed a tad too slow (50hz vs 60hz refresh)... Anyway, what I'm saying is that a composite monitor with sufficient adjustment in vertical hold mayyyy synch up NTSC picture right. However, I am wondering if it has to be a monitor with models sold in US/Japan like mine was to be able to recognise the NTSC color signal.

If you have a PAL TV that can decode NTSC composite (or a Multistandard monitor that can take composite), that'll do the trick nicely, no need to fuss with step-down converters and all that stuff.

Vynix wrote on 2022-09-29, 01:39:

If you have a PAL TV that can decode NTSC composite (or a Multistandard monitor that can take composite), that'll do the trick nicely, no need to fuss with step-down converters and all that stuff.

I'm curious as to how good or bad NTSC composite artifact color looks on a monitor or TV with a higher end 2D or 3D comb filter as opposed to one with a basic notch filter .

Apparently a simpler notch filter may yield better results shttps://nicole.express/2021/shouldve-had-field-sequential.html

Alternatively, one could use one of these https://www.serdashop.com/MCE2VGA with a VGA monitor (NTSC composite artifact colors are processed/converted into something VGA compatible) . See here for a review from a few years ago https://www.youtube.com/watch?v=9SII7ujB3FY .

EDIT : Forgot the video link

EDIT 2 : A Raspberry Pi RGB to HDMI also handles NTSC composite artifact color https://www.youtube.com/watch?v=p7ceH8Ol2qE

clb wrote on 2022-09-28, 20:19:

IBM PCs with CGA graphics adapters were able to produce "artifact colors" when running in the NTSC region

Even in PAL regions the IBM PC with CGA generates video with NTSC timings (262 lines per frame at 60 frames per second) on both the RGBI (digital) and the composite outputs. On the composite output, the colour information is encoded using NTSC.

PAL computer monitors such as the famous Commodore 1084S have an RGBI input and can display CGA video at 60hz perfectly fine. They can also display a black and white composite signal from the CGA at 60hz. What they can't do is decode the NTSC colour signal that the CGA generates.

If you want to view composite artifact colours from the CGA in a PAL region you just need a multi-standard television set (one that can decode both PAL and NTSC colour signals). These are quite common nowadays, although I don't think they were particularly common in the early 1980s when the IBM PC and CGA were introduced.

kdr wrote on 2022-09-29, 04:20:

clb wrote on 2022-09-28, 20:19:

IBM PCs with CGA graphics adapters were able to produce "artifact colors" when running in the NTSC region

If you want to view composite artifact colours from the CGA in a PAL region you just need a multi-standard television set (one that can decode both PAL and NTSC colour signals). These are quite common nowadays, although I don't think they were particularly common in the early 1980s when the IBM PC and CGA were introduced.

Those multi-standard television sets became more and more common since the 1990s, I think.
At least here in Europe/Germany.

The lower-end TVs, but with SCART, did usually support 60 Hz automatically.
Except for the colour, if fed with NTSC via CVBS (Composite) port.

Anyway, 60 Hz monochrome support was no problem, even in the 1980s.
Green/monochrome monitors or PAL video monitors had V-Hold, H-Hold knobs to adjust picture frequency.

That being said, the VIDEO port (RCA/Phono/Cinch connector) on many non-US computers was monochrome.

My Nixdorf 8810 M35 has on-board CGA, but does not support color burst signal. It's always monochrome.

Same for the Amiga 500. The VIDEO port is monochrome only.
The external video adapter module is required to get colour.

I assume, these has two reasons:
a) no need to pay royalties for NTSC patents and providing international video standards compatibility
b) the higher quality/resolution of a purely monochrome signal

The latter makes sense to me, since professional video monitors (for computer use) were monochrome only (called video display, data display).

On such monochrome monitors, an NTSC/PAL colour information causes unwanted artifacts/noise.

Think of green monitors, as they were popular with the Apple II and its clones.
The afterglow/long persistence phosphor made a normal TV grade video signal almost eye-friendly.
Like on a modern 120Hz/100 Hz TV 20yrs later.

That's also why the Amiga Workbench was Orange/Blue/White.
These colours provided both high contrast on a fuzzy monitor and their hues were monochrome compatible.

Edit: My apologies for this long post.

Here's something more useful..
a) There used to be video transcoder chips PAL<->NTSC, PAL <-> SECAM, RGB <-> PAL etc

b) All video signals are available on the CGA's DE9 port. So you can create an NTSC color signals externally with a little circuit.

Edit: On a footnote: PAL video recorders from Europe could display American/Japanese video tapes as PAL60.
This was a quick hack, essentially. And required TVs capable of 60 Hz.
Anyway, this means, NTSC and PAL existed in both 50/60 Hz flavors in the day.
Modern VCRs are (or rather, were) truely multi-standard, by comparison, I think.
DSPs and microcontrollers could perform needed tasks much better.

yes it's very possible
all you need is a tv/display that supports NTSC
here is my Hyundai XT with an IBM CGA some years back, I used a late-era sony tv that supported all color encodings:

it got replaced with a NTSC 1084 monitor that by pure luck I was able to find locally 😁

Thanks, super informative as always!

Now to do some shopping 😀

My 1024s was the one with a digital/analog switch on it for RGB input. I understand there were different versions of it, some less featured. I am recalling feeding it CGA on one or two occasions, whereupon I didn't need to fiddle with the hold to synch it, I guess because it had the synch signal. I don't know if it did artifact when connected like that, because I didn't know about it, and don't remember having any of the games that use it. Also it would seem to be skipping NTSC decoding which is the point where the magic or "turning a bug into a feature" happens.

clb wrote on 2022-09-29, 09:01:

Thanks, super informative as always!

Now to do some shopping 😀

There's another possibility that I had found out just recently! 😁

Some Apple IIs for the PAL market had an internal converter circuit that decode NTSC artifacts
and converted them to real colours, thus made them compatible with PAL.

This perhaps not the most practical way of doing it nowadays, but it is an interesting read, at least.

http://nerdlypleasures.blogspot.com/2021/10/a … color-ntsc.html

Jo22 wrote on 2023-01-29, 17:34:

There's another possibility that I had found out just recently! :D […]
Show full quote

clb wrote on 2022-09-29, 09:01:

Thanks, super informative as always!

Now to do some shopping 😀

There's another possibility that I had found out just recently! 😁

Some Apple IIs for the PAL market had an internal converter circuit that decode NTSC artifacts
and converted them to real colours, thus made them compatible with PAL.

This perhaps not the most practical way of doing it nowadays, but it is an interesting read, at least.

http://nerdlypleasures.blogspot.com/2021/10/a … color-ntsc.html

In Re: Is it possible to get CGA NTSC Artifact Colors when running an IBM PC in Europe? , I mentioned modern ways of doing essentially that but while outputting to VGA or HDMI. One could add an extra converter to end up with a PAL signal .

So, in a way, I would postulate, that it might actually be "the most practical way of doing it nowadays" 😉