No, it's just not done yet. Hopefully, one day it will be. It is not that difficult, just a matter of applying correct palette but there is one twist. The final image will look fine for amber and greyscale modes, those were typically quite sharp with very little afterglow; but it will be very far from the "uglyness" of the original green monitor. Do you want 2 seconds afterglow and blurry image as well?
I think, MESS does monochrome CGA.

Hummm, 2 sec. afterglow and blurry. That would be nice. 😀

Add all that black space between the pixels (0.4 dot pitch or higher I guess) and it would be perfect.

I happen to like the screen effects used on some Mame distributions. They add a old CRT feel to it...

Some shaders from my direct3d patch simulate the effect. But I'm not certain how real it looks since I never owned a green or amber monitor...

Very interesting those shaders!

Just tried the MCGreen.fx shader and unfortunately it really isn't much like the real thing (at least as far as green CGA monitor image is concerned). It sure makes things all green but besides being green the image it produces looks like it suffered from color reduction or something like that.

One game screen where this "color reduction" effect is very clear is the "Select Skill Level" screen on Test Drive II: The Duel. The skill bar has 12 levels, each one with it's own color (it uses patterns to make up for lack of real colors). With the shader 5 levels at the middle of the bar seems as they all got the same green color.

Strangely enough the matrix.fx shader is all green too but handles the patterned colors on the skill bar much better. It's just a pity it also has that funny outline effect on everything! 😁

Well, I guess I'll try and mess a bit with those shaders... that is... if I can understand then at all! 😉

In the 80's I were one of those that played games on CGA mode in a green phosphor CRT and loved it. Seeing CGA games today on all their real color "glory" don't fell like the real thing at all to me. It's like green (or ambar for that matter) was "The way it was meant to be played" all along Very Happy

I would find this to be very odd indeed. CGA stands for color/graphics adapter , which means it was designed for color monitors using a digital TTL RGB encoding @ 60Hz. There were better cards, the MDA and Hercules, that could be used with digital TTL monochrome monitors. They used long-persistence phosphors to reduce the flicker at 50Hz.

Now, CGA adapters cannot use mono displays and MDA adapters cannot use color displays. However, this assumes you are using IBM hardware. There were clones that supported both MDA and CGA standards and supported both types of monitors. To use a CGA modes on a monochrome monitor would require the card to translate the data into something the monitor can display.

However, there is an easy way to do monochrome CGA, use a monochrome analog monitor, which the Apple IIs used. Works for every CGA mode and CGA does assign unique luminence amplitude values to each of the 16 colors in its palette. All this requires is full composite color CGA support, unlike the halfway support currently available (but for that to happen there would have to be a composite CGA mode added to the adapters DOSBox supports.)

Great Hierophant wrote:

Now, CGA adapters cannot use mono displays and MDA adapters cannot use color displays. However, this assumes you are using IBM hardware. There were clones that supported both MDA and CGA standards and supported both types of monitors. To use a CGA modes on a monochrome monitor would require the card to translate the data into something the monitor can display.

Actually I remember I owned 8088 machine with hercules graphic card and cute amber monitor. I could run cga games running cga-card emulator (TSR program) for the hercules. If DOSBox could emulate hercules, one could use those tsr emulators to run cga games and get monochrome display. (heh, DoSbox emulating hercules, so you could run program emulatnig cga on it; Funny, but would work 😀).

However in DOSBox, for practical reasons it would be easier to apply a filter to get that effect.

I would find this to be very odd indeed. CGA stands for color/graphics adapter , which means it was designed for color monitors using a digital TTL RGB encoding @ 60Hz.

I remember PC color monitors being very expensive and people that wanted color would use CGA cards with TV-Outs as an alternative. The funky CGA palletes and lack of sharpness of TV made the "green" monitors actually look very good in comparison.

However, there is an easy way to do monochrome CGA, use a monochrome analog monitor, which the Apple IIs used.

Now that you mentioned, I guess what I used at the time was in fact a composite monitor. It was all green, but not really monochrome. Oh well, I was only a child and I was told it was monochrome... so kept that wrong definition for no good reason.

Jeez, I guess the topic title is wrong then! It should be "Green Composite CGA simulation. Is it possible?" 😁

I feel the same,like old times.
Next version should come with Green phophor or Ambar monitors emulators like BlueMSX(MSX Emulator) that you can choose which kind of monitor you want to use,blurry or sharp with scanlines and everything.
Good point!
EdusP

Oh well, I was only a child and I was told it was monochrome... so kept that wrong definition for no good reason.

They weren't wrong, they were just exposing a technical definition of color. Monochrome means one color, not black and white. If all that monitor could display was either green and black (or amber and black or white and black), then its a monochrome monitor. Even though it could display multiple intensities of green, as it could with an attached CGA, does not make it a color monitor in some definitions.

Oh well, I messed with the shaders but had no luck with them... to be fair, with the knowledge I have on shaders making it work would be a matter of pure luck indeed.

In the end I tried MESS as vasyl suggested. It does simulate a mono monitor so that you end with shades of gray that really looks like the real thing.

Gray... yes.. no green for me yet but I guess it's good enough as it is.

I used the "PC (CGA)" system, mounted a DOS 3.3 boot floppy in the Floppy Disk #1 and once running choose "Mono RGB" on "Options/Configuration/CGA monitor type".

The whole process of making it work definitely isn’t as easy and straightforward as using DOSBox. Then again if you really used DOS 3.3 back at the time you wouldn't expect things to be easy anyway. 😉