[marshray]

> NES games never drew their own sprites. They just said "Hey NES, write the sprite at this x and y location"

Yeah, but the hardware is so limited with weird corner cases that writing a bitblt might be easier. For example, some games have to reconfigure their sprites at the beginning of every horizontal scan line to overcome the hardware limitation on simultaneously displayed sprites (8).

[klodolph]

Which games? To my knowledge this is at best exceptionally rare because there are only ~114 CPU cycles in a scan line. The reports I've heard are that if you do any OAM changes mid-frame, you get something like four lines of glitches. More common is to just do a full OAM DMA during vertical blank, at least from the ROMs I've seen.

[marshray]

I can't find the original link where I read about this, it may have been more theory than about specific games. These links seem to be relevant: http://wiki.nesdev.com/w/index.php/Sprite_overflow_games http://forums.nesdev.com/viewtopic.php?t=16299