Large ROM images and Sega CD + 32X
Posted: Sat May 20, 2017 7:53 pm
Okay, so I got my Everdrive X7 and all was well until I tried running some large homebrew images on a Wondermega. As soon as tried an image exceeding 32 megabit, I got an error message prompting me to unplug the CD and 32X add-ons. The problem is, Wondermega, just like CDX and X'Eye, has the CD module integrated.
I do understand that regular cart space is mapped up to $3FFFFF, but I thought that space above that, up to $7FFFFF, could also be used by a flat mapped cartridge without a CD present. After all, the drive stays inactive when a cartridge is inserted. What would happen if this check was disabled and Everdrive would try to run large ROM images on a Wondermega [or CDX, or X'Eye]? Would this guarantee a bus conflict?
I have posted this question on the Mega Everdrive subforum, but unfortunately it remains unanswered. I guess I never thought of the bus conflicts, because no "normal" game is this big, and the modern big stuff, like Overdrive II, uses bank switching. But there are things like What Is Love, which are huge, but flat mapped. Anyway, I'd appreciate any kind of definite clarification when it comes to systems with an integrated CD component and bus conflict issues. Thanks!
I do understand that regular cart space is mapped up to $3FFFFF, but I thought that space above that, up to $7FFFFF, could also be used by a flat mapped cartridge without a CD present. After all, the drive stays inactive when a cartridge is inserted. What would happen if this check was disabled and Everdrive would try to run large ROM images on a Wondermega [or CDX, or X'Eye]? Would this guarantee a bus conflict?
I have posted this question on the Mega Everdrive subforum, but unfortunately it remains unanswered. I guess I never thought of the bus conflicts, because no "normal" game is this big, and the modern big stuff, like Overdrive II, uses bank switching. But there are things like What Is Love, which are huge, but flat mapped. Anyway, I'd appreciate any kind of definite clarification when it comes to systems with an integrated CD component and bus conflict issues. Thanks!