VRAM Offsets

[Sylus101]

I believed I had already had a pretty good handle on this, but as I'm trying to review it I'm missing something.

What exactly does using the offsets for VRAM Banks do? The starting address changes by 0x20000 which is 128k, basically moving into another banks space? Yea, I'm confused. Any practical example of why you'd use an offset at all would be very helpful. I picture maybe the need to Shift Bank B a bit to give more room to A, but that seems like making something out of nothing...

[eKid]

If you take vram A and B together, offset B by 128k, then you can make a big 256k bank. The 'large bitmap' bg mode I think uses all four banks combined.

[Sylus101]

Okay wait... A, B, C, and D all start at 0x6000000 technically and the offsets of 128k steps for B, C, and D are the "defaults" (reviewed video.h again...) Okay duh... Now I've got it. I know I had come to that conclusion before but somehow lost it in all the new information I've been taking in.

Thanks!