Thanks for the great info.lordofduct wrote:This is a thing that people have been screaming about for years.
Over at SX in the Sega Genesis/SCD dev and help sections one of their rules (which has been in effect for several years now) is to not even bother asking about playing Sega Genesis games via the CD-Rom of the SCD. There have been several lengthy discussions between hopeful gamers, programmers, and others on the topic (don't feel like digging for them).
The big problem is where to load the rom into for the processor to handle its information. You figure it this way, games on a genesis average 4-8 megabits, and climb to 32megabits (not to be confused with megabytes). The cartridge slot is directly accessed by the motorolla 68000 (the main cpu of the genny) for playing the game. With out the memory on the cartridge there is no space anywhere on the console to store that data for access by the genny. There isn't enough memory on the console to do so... even considering the extra memory the SCD adds.
Now in the case of that "Sega Classics Collection"... they are kinda a port... not really a port mainly because its the same freakin' hardware. But the games had to be modified to be playable on the SCD. I'm not sure exactly how, but by looking at the disc itself, from what I can tell is that the game was broken into several small parts that are then controlled by another program. These parts are loaded into the limited amount of memory when needed, and removed when not needed. (just like most disc games).
Other issues that come in are the fact that when the genesis boots up it checks the cartridge slot. If nothing is in the cartridge slot (designated by a certain pin) it automatically boots off the expansion port. If the SCD is connected to the expansion port it loads up the bios of the SCD as if it were a game cartridge, then putting it into SCD mode. To load and run a genny game you'd need some type of storage area for the game, and a way to drop back into genny mode.
And streaming the games like in the case of Sega Classics Collection... you'd have to create a build on a game by game basis. Basically porting it, in a sense, like I said it's not porting by definition. Its just you have to change the architecture of how the system looks at the game.
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then again no one will trust what I said. But I tell you, have fun asking any of the genny programmers/hackers out there. I guarantee they probably won't appreciate the request.
i know, because I made the same fatal mistake myself several years ago.
Anyways, if they just made some type of bypass cart then thats a good possibility. you can have the cartridge load the roms off of the cd. but whatever sounds to complicated to me to get deep into.
I may look into the cartridge that plugs into the PC.
Soooo...Mabye the 32x has enough memory. They make Sega CD 32x games that run from the CD to the 32x's processors/memory. Mabye there is a way to make them, but it would require a 32x attached.
