tepples wrote:
TmEE: "Passive" means vertical blank period, right? If so, the DMA bandwidth to the Genesis VDP in H256 mode appears almost identical to that to the S-PPU after deducting time to copy the sprite attribute table and a row or column of background map. The advantage of "Blast Processing" over DMA to the S-PPU is really just the ability to decompress tiles (Nemesis, Kosinski, etc.) directly to VRAM without using any vblank time.
Yes, it means vertical blanking period. I don't think there are many games that touch VRAM from active display. You still get 16 or 18 bytes per line and could use that to transfer some/all of the sprite list during a statusbar etc.
ccovell wrote:
Blue's Journey on any Neo-Geo and double-check that the borders around text during the introduction or in-game are all visible. That's 320 pixels.
Unfortunately I don't have that game (and it seems way out my budget too), I only have the Metal Slugs, Neo Turf Masters and Riding Hero and none of those do more than 304 no matter what I tried. My TV shows almost all the image from sync to sync with only few pixels worth clipped off on left side in the porch so it isn't a matter of me not seeing the pixels if they were there, plus I had scope running simultaneously and it never showed any activity at the edges of regular active display area when I was testing around.
EDIT: When I looked through my chat log with Furrtek I saw that I did manage to get some noise show up in the sides of screen when I toyed around with some control signals but there was never any actual graphics there.
I'll remain unconvinced about the 320 pixels until I see them myself. I don't plan to take up NG programming yet and I'm not very familiar with the machine to write a small test ROM anyway that would set up things so that in theory there will be stuff visible at the sides. I could swap out the 68K program ROM in one of my carts for sake of testing.