Just found the pointers to the auto-scrolls in SMA3.
There are 14 different ones in the game. The SNES had 11.
It's obvious, that two of them are used. One of them in Secret 4 and the other one in Secret 6. Don't know what the last one is for, though...
Anyways, the pointers go from 0x17CE84 to 0x17CEBB.
The last three auto-scrolls are this:
Type-L (Used in ??? Looks like a level you must climb, looking at the Y-coordinates!)
0C 70 08
14 6E 08
1E 70 08
2A 6A 08
2E 6A 08
3B 70 08
53 70 0A
71 70 0A
8F 70 08
98 67 04
8F 5B 06
90 2E 03
94 2C 08
9D 2C 08
A6 2C 08
AD 2F 0A
B6 36 08
CA 36 08
D4 3A 04
E2 43 08
F0 3F 08
FF
Type-M (Used in Secret 6)
30 60 14
60 60 10
96 60 16
D1 60 08
FF
Type-N (Used in Secret 4)
4C 60 12
61 5D 14
72 60 12
90 5F 12
BB 5D 06
C9 5F 0A
FD <------- Special command: releases screen downwards & to the right
(00 00 00) Probably unused space
EDIT:
It's weird: I've experimented a little with room EA and found out, that in the GBA version the Bullet Bill Shooters (I've tested it with all of them) on platforms (Sprites 089 and 08A) only appear under certain conditions. If one is standing on the right edge of a platform, it only appears, if you come from the left. If one is in the middle it always appears, and if one is on the left edge, it only appears, in case you are coming from the right. I've also tested it with the line-guided green platforms. They always seem to appear on them. That's really weird, since the other sprite, which can stand there, the Egg/Cactus-spitting flower (Sprite 0F4) always appears, no matter on what edge they stand.
Also, other things about the auto-scrolls:
6-8, Secret 4 and Secret 6 all use GBA sprite 1D4, which is auto-scroll Type-A.
BUT, obviously, it is able to activate three different auto-scrolling types, which are at least Type-M and Type-N.
The sprite 1D4 itself is not dependant of any X/Y coordinates in its levels, since in two levels it's the same.
I found out, that the sprite is also not dependant of the translevel number, but on the room number instead.
If 1D4 is placed in another room than 6B or EA, then it will behave like it does in Secret 6.
Nintendo tweaked it twice for EA, since there the sprite activates a scroll differently from the one in Secret 6 plus in Secret 4 free vertical scrolling is inactive. In 6B and Secret 6 free vertical scrolling is active, but can't be used, since both are horizontal rooms.
With a few tweaks, it also might be possible to fully make this sprite X/Y dependant, so it activates Type-A, Type-L, Type-M or Type-N depending on the coordinates.
Furthermore, there's an unused special ending command FC for auto-scrolls, which works like FF. It might be possible to edit FC.
The SNES version also has an unused auto-scroll IIRC, since there's twelve pointer as far as I know.
I'll check now, whether the special commands other than FF and FE can also be used in the SNES version.
NEW! SMW2 Yoshi's Island is done!
Last update: 2012-12-31