MottZilla wrote:
I'm not a huge fan of CHR-RAM, though it really depends on the project if I'd prefer RAM or ROM. Mainly I don't like CHR-RAM as you have no options for banking, and there is no DMA to VRAM like on SNES.
Lately, I'm starting to prefer CHR RAM. On NTSC, without using sprite 0 or an IRQ to end rendering early, you can blast 160 bytes to VRAM every frame in a 16x unrolled loop and still have time to blast OAM. (At least it works in Nintendulator and Nestopia.) That can be useful for double-buffering each sprite's next frame of animation, up to 10 tiles at a time. If you want to do something like the background tile animation seen in SMB2 and SMB3, you'll need a mapper capable of swapping 2 KiB or smaller CHR banks, and that's expensive to reproduce because you can't just use the CPLD MMC1 clone.
MottZilla wrote:
If you have to use a real game please make sure it sucks and is common.
In that case, I've been told that UNROM (common as dirt) or BNROM (Deadly Towers) makes a good CHR RAM devcart. If you can't find those, you can put together a complete ReproPak from parts for under $20.