SpritesMind.Net

what would be great for the megadrive is a super gamegear, bit like "nintendo's super gameboy for snes" now if they could make a cart that worked with gameboy / gameboy colour games, it should in theory be possibull to make a game gear -> megadrive adapter, now you might be thinking theres not much point since most of the games on a game gear were availbull on the megadrive, yet i dissagree, and think it would be a execlent idear now the only problem is the fact of you cant get the gg cart slots, but since faulty game gears are so easaily availbull on ebay it would be easy to get one for the cart slot, ive got 6 faulty gg my self

let me know if this is possibull at all

Ben

As far as I know, the game gear was compatible with most SMS games (via Master Gear Converter), but not the other way around - game gear had some hardware that MS did not (deeper color palette, etc.). If the game was just the SMS code in a GG cart, then it might work, but if it was written specifically for GG, I doubt you'd have much success. Maybe someone with more knowledge on the subject can provide more information.

thats why the hardware being the conveter, would have all the required chips etc to convert gg only games to sms games on the fly, as the gg can only display 32 colours on the screen at anyone time

Ben

with modern ic's fpga's i dont see that it would not be possibul

Both SMS and GG can display only 32 colors simultaneously. Difference is that GG has larger palette - 4096 colors instead of 512.

Modern FPGA allows you to make SMS/GG replica which can be connected to TV or monitor, without using SMD and even without real GG carts, if you want. And I think, it will be easier than making converter.

Isn't it also possible to add TV Out to a GameGear? I've seen this done for RGB, anyway. That'd be a much simpler project.

Doesn't the VDP has a 9bit pixel bus output? You could pass that through another DAC. I mean, talking in terms of hacking or creating a special setup. Each game would need to be hacked for palette data write redirection, though.

Yep it does, (10bits). It needs to be activated by setting some bits in it's registers. But it's not RGB, it is to connect an external pallete, and an external DAC.

The pallete + DAC need to be made manually and its DMAs/normal writes need to be captured.

Also SPA/B and YS are unneeded for this.

And there are more 10pins with unknown function but for sure they aren't no-connects, because all of them have internal pullup (the VDP fab process is somekind of NMOS technology).

Jorge Nuno wrote:Yep it does, (10bits). It needs to be activated by setting some bits in it's registers. But it's not RGB, it is to connect an external pallete, and an external DAC.

Yeah, it's just multiplexed pixel/palette/priority data - no RGB. But 10bit? What's the format? You only need 4bits pixel, 4bits for palette, and 1bit for SPRITE pixel or BG pixel (priority bit).

Color index: 4 bit
Pallete select: 2 bit
Shadow/Highlight: 2 bit
Optional pallete selection for sprites (SPA/B): 1 bit
VDP output or external video source(YS): 1 bit

Oh, thank you for that bit of info

/saves