Originally posted by Great Hierophant The CGA colors are less than ideal,

Yes, that would be the "far-too-polite" way of saying it.

...but most computers at the time it was introduced (1981) did not use crisp RGB monitors but even crappier composite monitors.

Giving us a crisp display of crap, instead of a crappy display of a tolerable palette.

But I prefer that we get the colors and palettes accurate first, then worry about selecting colors.

Fine. It seems pretty accurate as is. But by all means fine tune it...

The Tandy 1000 PSG emulation is incomplete as of the public .58 release. The emulation can generate tones, but not noise that the Tandy's PSG can also do.

True. I was thinking more in terms of CanadaCow's version and I should have specified it:
showthread.php?threadid=2319&highlight=tandy

Perhaps they have implemented it in the CVS?

I think CanadaCow's version is the most advanced version available. He seems to have lost interest in it since he's started his MT32 emulation crusade (and a mighty crusade it is...).

Geeze guys, lay off the purist CGA addict.

What do people hate the most about the CGA? The limited 16 color palette, which I gave an example above? The 3-color palette limitation? The inability to set the colors? Originally it was very slow, but now that is not an issue.

Accuracy is most important with the CGA emulation. DosBox .58 is not very accurate. Contrary to popular belief, not all games use palette 1 at high intensity, which is what .58 does.

As for the poor color/sharp display argument, don't forget that the CGA was capable of 16 colors at 160x200 resolution in its artifaced composite mode, rivaling similar Atari and Apple modes. Too bad too few people every enjoyed it, because a fair amount of older software actually supported it.

Also, I am waiting for the day that DosBox will run Icon - Quest for the Ring. That is a CGA game that does full 16-color graphics, and my modern PC can run it without difficulty, but DosBox cannot.

No other project is more necessary than accurate MT-32 emulation. Canadacow's work is very promising, if he can just get that reverb down.

As far as i can see icon runs in the current cvs and it just uses 16 color text mode.

[quote="Snover [/i]Geeze guys, lay off the purist CGA addict. [/quote] My problem is not with the purist, my problem is with CGA.

Originally posted by Great Hierophant What do people hate the most about the CGA? The limited 16 color palette, which I gave an example above?

16 colors was a perfectly acceptable limitation of the time, considering what hardware was available.

The 3-color palette limitation? The inability to set the colors?

The combination of these two. IBM could've done much better than this, they just chose not to...

As for the poor color/sharp display argument, don't forget that the CGA was capable of 16 colors at 160x200 resolution in its artifaced composite mode, rivaling similar Atari and Apple modes. Too bad too few people every enjoyed it, because a fair amount of older software actually supported it.

Yes. I'm well aware of it. It was the preferred method for running much of the (really) older software. The original "King's Quest" being a perfect example.

Also, I am waiting for the day that DosBox will run Icon - Quest for the Ring. That is a CGA game that does full 16-color graphics, and my modern PC can run it without difficulty, but DosBox cannot.

Originally posted by Harekiet"]
As far as i can see icon runs in the current cvs and it just uses 16 color text mode.

A little more complex than that:
http://www.mobygames.com/featured_article/fea … e,10/index.html

Just a quick note: My tandy patch includes support for both the correct CGA mode implementations as well as MAME's Tandy sound emulation.

Does anybody knows if the 16-colour CGA Mode on the AMSTRAD PC1512 was the same as Tandy's?

P.S: I have seen this mode once, used by an earlier Infogrames game. Don't remember exactly which one (Iznogoud?). Maybe some others around this time, had the same support for the aforementioned mode.

hmm as far as i can see the amstrad's 16 color modes used 4 different planes for red,green,blue,intensity instead of the tandy which just has 2 pixels packed into 1 byte.
So amstrad seems more like EGA without all the freaky write modes.

Thanks for the reply. It was paradise who developed the CGA chipset on these AMSTRAD machines, btw?
In 1988 i had an AMSTRAD PC2086 (paradise VGA). Best VGA i have seen. It could emulate everything (from hercules to CGA/EGA) perfectly.

CGA Emulation with old sierra quest games is getting somewhat weird, since it can seem to run in 320x200x4 color or 640x200x2 color mode. But i need to hack the cga_graf.ovl driver a bit to get the 4 color mode, very strange. Looks whacked though 😀

Or with 4 colors

Check out my Tandy patch source as to how I fixed this for CGA support.

your tandy patch wasn't right at this, the game first sets videomode 0x4 and then programs the hardware directy to go to 640x200. Tried it in MESS XT-CGA emulation too, then it also gives the 640x200 version, but it's just strange since when you look in cga_graf.ovl it can also run in 4-color mode like i've shown here, but that test can never be sucessfull since the detection code in agi seems fucked.

Don't forget that in my Tandy version you have to explictly change the mode (from CGA, Tandy, and VGA) for the detection routines to work right. I just went back and tested it with PQ1 and the CGA stuff looks exactly as I remember it.

hmm stupid the 640x200 mode it sets also sets the the special video out bit so it turns into that 160x200x16 color mode, let's see how that can get hacked in somewhat.

I hate to keep bugging you, but that too (composite CGA), is built into my Tandy patch.

I have a question about the CGA emulation of the DosBox with Tandy support, and now I know who to ask. I noticed that when I use the old CGA color composite mode with games that support that mode, Sierra's AGI games and The Bard's Tale I, the colors seem to be slightly different from the Tandy and EGA palettes.

It seems like the emulator switches the colors of red and purple. Red objects, like the castle banner in KQ1 become purple while purple objects, like the shadow of the purple flag, are now red. Does the real CGA color composite mode do this also? I have attached a comparison example of what KQ1 looks like in EGA/VGA and what it looks like with the color composite CGA mode. The top screenshot shows the game in standard EGA/VGA, and the bottom screenshot shows the game using DosBox's composite CGA mode, minus the graphic bugs and text fringing.

How does one select colors for pixels in the composite graphics mode? In the 320 pixel modes a pair of bits can select a pixel's color from one of the four colors available. In the 640 pixel mode each bit selects the pixel color from the two colors available. Since the color composite mode has a horizontal pixel count of 160 pixels, I would assume that each nybble would choose the pixel color of one pixel from the 16 colors available.

It's quite euhm strange that composite mode, since when i use screenshots of mobygames of some, like mean 18. First of all in the mean18 i seem to notice there's 3 shades of green in the title shot. Which is somewhat strange with only 2 being in the cga palette.

Then i made some kind of conversion table for converting the nibbles of the composite mode to normal cga colors, but if you have 1 game looking like the ega version mean 18 screws up again. Gonna need to do some testing on a real cga with composite out to be sure i think 😀

The color bleeding is also quite horrendous, whereas you see the screenshots of certain games like flight simulator 3, the display panel at the bottem is quite readable, but in the emulator it's horrible 😀

There are some issues with VGA i've noticed.

1.VGA mode 11 (640x480x2) is not emulated.
Game Hound of Baskerville (->the underdogs) uses this mode.
And it doesn't even run properly in pure DOS on my Radeon: if I move mouse during a screen change, output becomes garbled.
Dosbox (CVS) gives "unhandled VGA mode 7" when this is run.
Btw. in DOS, this game has colors, which is strange for a monochrome color mode.

Prehistorik 2 runs with a black screen, but sounds can be heard in background.
Another game, Virtual Pool for some reason draws only half of the screen in 320x240(200?). This game has support for VESA 640x480 but it's drawn incorrectly too.

Reg. Virtual Pool: Half-screen horizontal, or half-screen vertical? Also, in the future, please post specific game problems in the designated forum in a separate thread for each program.