you have set the machine to cga ?

coolhaken wrote:

I use a TSR named COMP4.COM from CGA Composite Mode under DOSBOX (Commited r3804) to force it run in CGA composite mode.

Zak McKracken uses mode 4 (320x200) for composite output, which is currently not supported by DOSBox. That TSR forces it to use mode 6 (effectively), which is supported, but the resulting palette is completely different so the colors will be wrong.
There's a patch later on in the same thread that adds composite support in mode 4. It's still a work in progress however.

coolhaken wrote:

But the horizontal position does not at center.

The game doesn't appear to do anything unusual with hsync position for hercules graphics, so maybe it's just like that. Perhaps Hal can check it on his herc clones.

VileRancour wrote:

That TSR forces it to use mode 6 (effectively)

To clarify, COMP4 causes DOSBox to use 160x200x16 composite drawing while in mode 4. The earlier COMP6 did change mode 4 into mode 6, but that wasn't necessary, and in fact was problematic. The colors are indeed wrong with COMP4, though.

Actually, I think it might be worthwhile to take a closer look at the composite mode of Maniac Mansion and Zak McKracken (both original and enhanced versions) with the patch being developed, because the colors seem strange no matter how I try to adjust them.

VileRancour wrote:

There's a patch later on in the same thread that adds composite support in mode 4. It's still a work in progress however.

Thank you ! I download dosbox_composite.zip. The game's color then looks better. (but auto-detect doesn't work)

ripsaw8080 wrote:

The game doesn't appear to do anything unusual with hsync position for hercules graphics, so maybe it's just like that

Yes, I played this game in M.E.S.S. and PCE. They are all in the same state.
I can adjust the monitor on real machine. But I can't do this in DOSBox.
If this is the only one case, please don't care it or make patch for it. 😀

ripsaw8080 wrote:

To clarify, COMP4 causes DOSBox to use 160x200x16 composite drawing while in mode 4. The earlier COMP6 did change mode 4 into mode 6, but that wasn't necessary, and in fact was problematic. The colors are indeed wrong with COMP4, though.

Actually, I think it might be worthwhile to take a closer look at the composite mode of Maniac Mansion and Zak McKracken (both original and enhanced versions) with the patch being developed, because the colors seem strange no matter how I try to adjust them.

I stand corrected - COMP4 never sets mode 6 as such. The value written to port 0x3d8 just sets bit 4 high and bit 2 low, which translates to 640x200 graphics w/color burst enabled: this triggers DOSBox's composite detection which (in turn) only emulates mode 6 behavior as of now.

As for the colors, perhaps these games were tested on a Tandy or so in development? In mode 4 that would entail some more tweaking, similar to PCjr. I'll try to do some testing later and post the results in the relevant thread.

coolhaken wrote:

(but auto-detect doesn't work)

It doesn't work by design, you have to toggle composite on in 320x200x4 modes to get composite output. If the monitor= setting discussed in the other thread is fully implemented at some point, monitor=composite would automatically have composite output in ALL modes, including text modes.

VileRancour wrote:

As for the colors, perhaps these games were tested on a Tandy or so in development?

The games have support for Tandy 16-color graphics, so I think it's possible that the composite mode was developed on Tandys, and the developers might not have been aware that the colors would be different on "regular" CGA.

My goal in trying to adjust the composite colors was to achieve green grass without the other colors looking strange.

The Hercules screenshot is accurate, as the game is fitting 640x200 graphics into a 720x348 resolution. Would have been nicer for Lucasarts to have centered the graphics, but that probably would have been more difficult.

NewRisingRun indicated years ago that Maniac Mansion and Zak McKracken had kinda lousy support for CGA color composite. The 640x200 mode would have been better, and it is much closer to how they did it on the Apple II.

Tested and posted results here - Re: CGA Composite Mode under DOSBOX

I made an error with the Hercules graphics.

Zak is designed to run in a 320x200 resolution. The Hercules graphics mode uses a 720x348 resolution. If you were to put the original graphics inside the Hercules mode, you would have a very small graphics window in the middle of your screen, so they had to use a scaler to make the graphics appear larger.

Since the game uses a 320-pixel horizontal resolution, there is little difficulty upscaling by 2 to 640. Since the horizontal resolution of the Hercules graphics is 720, this leaves the game with 80 empty pixels. As for the vertical resolution, the game actually seems to use 340 lines between the status bar, graphics window, commands and inventory. In the 320 modes, the graphics window has a height of 128 pixels. In the Hercules mode, the height is also a multiple of 2, 256 pixels. The text remains at 8x8 pixels and there are 8 rows of text on the screen for 64 pixels, either in 320 or Hercules modes. That leaves 8 unused vertical pixels for the 320 modes and 28 unused vertical pixels in the Hercules mode.

It is possible to eliminate the extra black borders with machine=hercules by using Magic Key and running the game in CGA mode, although it will have a somewhat different appearance. Magic Key changes the display dimensions to 640x200.

Not too shabby at all... especially with aspect correction. I assume that on real hardware the image would be vertically squashed?

VileRancour wrote:

I assume that on real hardware the image would be vertically squashed?

Might be. I guess it depends on mono monitor behavior, but most likely one can manually adjust the vertical size with a knob or so. DOSBox uses a fixed 1.5 pixel aspect ratio for Hercules so 720x348 becomes 720x522 (almost, but not quite, 4:3), and 640x200 becomes 640x300. My SVN test build has a modification that calculates the pixel aspect ratio to always get exactly 4:3, for better or for worse, so 720x348 becomes 720x540, and 640x200 becomes 640x480. Probably not any kind of "accurate", but it hasn't yet offended my sense of proper proportion. ;)

ripsaw8080 wrote:

It is possible to eliminate the extra black borders with machine=hercules by using Magic Key and running the game in CGA mode, although it will have a somewhat different appearance. Magic Key changes the display dimensions to 640x200.

Hahaha ... another cheating ... 😉
I believe this is practicable on real machine, too.

ripsaw8080 wrote:

VileRancour wrote:

I assume that on real hardware the image would be vertically squashed?

Might be. I guess it depends on mono monitor behavior, but most likely one can manually adjust the vertical size with a knob or so. DOSBox uses a fixed 1.5 pixel aspect ratio for Hercules so 720x348 becomes 720x522 (almost, but not quite, 4:3), and 640x200 becomes 640x300. My SVN test build has a modification that calculates the pixel aspect ratio to always get exactly 4:3, for better or for worse, so 720x348 becomes 720x540, and 640x200 becomes 640x480. Probably not any kind of "accurate", but it hasn't yet offended my sense of proper proportion. 😉

On the IBM 5151, you cannot adjust the monitor height. The aspect ratio of the monitor is 5:4, but you also need to take the borders into consideration.

5:4 sounds a bit off - admittedly I don't have a 5151 on hand, but the web seems to have some nicely-oriented images to go by. ;) Looks somewhat wider than that, maybe closer to 7:5.

The mono monitor I used did have some kind of vsize control, but it was some no-name brand thing that supported both MDA and CGA signals/timings (so aspect was probably off for one or the other).

NewRisingRun indicated years ago that Maniac Mansion and Zak McKracken had kinda lousy support for CGA color composite. The 640x200 mode would have been better

Right...he found that they just dump the Tandy graphics data into B800 when Ctrl+P is pressed. Apparently LucasArts had no idea how composite graphics are supposed to work and assumed it was like Mode Ah.

and it is much closer to how they did it on the Apple II.

Yes, Apple Maniac Mansion runs in DHGR mode. The Zak McKracken manual has loading instructions for the Apple II, but that version was never released. I have no idea why, but I suspect that the Apple MM sold poorly (it certainly seems to be the least well-known version of the game) and they possibly thought making Zak for the platform wasn't worth it.