Very nice, I would like to see it in Magellan. Is it ordinary graphics mode?
There are many nice versions out there that don't necessarily have continuous smooth scrolling.
No, it's bitmap mode. In ordinary graphics mode, there would be more color clashes. In bitmap mode, you can get it with almost no color clashes, at least if you do away with the shadows and the shading.
The versions in this video which don't have continuous smooth scrolling are made by Melbourne House (for the Spectrum and the Amstrad) and are based off "Gyroscope" they did earlier as an unofficial Marble Madness clone. Those versions also have very few similarities to the arcade version regarding the maze structure and the enemies. But the Spectrum version of "Gyroscope" gave me an idea how Marble Madness could be done with relatively clean graphics. Of course you could do it that way on the TI-99, but I always thought this is somewhat poor. There's another version not shown in the video, which is an LCD game by Tiger which actually has converted to 2D and is rather like the rolling ball mazes out of wood which you can buy as toys.
I've attached what I have so far as a Magellan project here:
Marble Madness V5_mag.zip 3.34KB
It's the first three levels of the game. The third level could still use some refinement as it doesn't come near to the maximum number of transitions yet. I thought of adding the "cyan area" at the bottom where there are waves in the original. If there's no room for waves, you could just drag the ball to the lower right when on this area.
Just an experiment. An obvious trick for getting less color clashes with the 9918A is to make pictures wider as in more of the same color horizontally.
I took a 128 x 192 pixel snapshot - half the width of the TI screen.
Repeated all pixels horizontally.
Remapped colors manually and secured a max of 2 colors per 8 pixels horizontally - with a few manual corrections.
Now besides vertical scrolling, you'd also had to worry about some kind of horizontal scrolling. One could have a system with which the screen would scroll on 8 pixel boundaries (both ways) and center the marble in a Zelda type fast scroll when it came within a distance of 40 pixels from the border.
Well, also if not doubling the width, you could do a much better approximation of the arcade graphics than I did... the TI-99 would be capable of it, graphically. The reason why I simplified my version so much is actually the "transitions"... I imagined it to be scrolled the same way as in "Titanium", and there every transition from a character to another counts as a character to be scrolled, and there are only a maximum of about 128 transitions allowed for each level... maybe even fewer if you need static text for scores etc. This limits the complexity of the screens severely. If you do character-wise scrolling instead, the graphics might be better as well, since then you basically have full bitmap mode... as long as you can cram it into memory somehow. Even with 256 distinct characters per level, you can do much better than I did... I think in my version, each level only uses 40-50 distinct characters. I had a preliminary version (which I also attached as 1st try) where I tried to do it as faithful as possible, and there I ran out of transitions after about half a screenful of data. This one is here:
Marble Madness 1st try_mag.zip 1.3KB
Finally, an XBASIC version which I wrote back in 1987... this one scrolls in steps of 4 characters and only has the first two levels (also not as true to the arcade as the Magellan maps since I did most of it from memory). Use with Classic99:
YIE AR KUNG FU ,beautiful game.
Rasmus can do this miracle?
Well, there's an MSX version of that game, also by Konami. It's fairly good graphically, although it moves the enemies in 8-pixel steps. I don't see to many problems putting up a TI-99 version like that. Of course, it's a time-consuming process. I once did a version in XBasic on the TI-99 myself, but in my version, two players play against each other with magnified, monochrome characters and no background graphics at all.