SMS save format

Offset	Size
0000	0040	Directory entry
0000	0006		Game ID
0006	0001		Unused (0xFF)
0007	0001		Bit 0: Banner format (0 = RGB5A3, 1 = CI8)
			Bit 1: Banner present?
			Bit 2: Icon animation (0 = forward, 1 = ping-pong)
0008	0020		File name
0028	0004		Last modified (seconds since 01/01/2000 0:00:00)
002C	0004		Graphics offset in file
0030	0002		Icon GFX format (2 bits per icon)
			00 = no icon
			01 = CI8 with a shared palette after the last frame
			10 = RGB5A3
			11 = CI8 with a unique palette after the frame
0032	0002		Animation speed (2 bits per icon; x4 frames; 00 = no icon)
0034	0001		File permissions (2 = public, 3 = no copy, 4 = no move)
0035	0001		Copy counter
0036	0002		First block
0038	0002		Blocks used
003A	0002		Unused (0xFFFF)
003C	0004		Comments offset in file

0040	2000	Block 1
0044	0020		Game name
0064	0020		File info

0084	0C00		Banner
0C84	0200		Banner palette
0E84	0400		Icon 1
1284	0400		Icon 2
1684	0200		Icon palette

1884	0004		Should be 0x00000002, otherwise reset options
1888	0001		Section 7 (rumble, surround, subtitles)
1889	0004		Section 8 (language)

203C	0004		Block 1 checksum

2040	2000	Block 2
2040	0004		Write counter
2044	0004		0x00000004
2048	0008		Last save time (ticks)
2050	0008		Zeroes
2058	0004		Save count (if 0, file is considered empty)
205C	0002		Shine count
205E	0042		Zeroes
20A0	0200		Section 1 (only takes 0x77 bytes, rest is zeroes)
22A0	0200		Section 2 (only takes 0x54 bytes, rest is zeroes)

403C	0004		Block 2 checksum

Blocks 3-7 follow the same pattern as block 2. Each save file uses two blocks to avoid losing data: saving overwrites the oldest block (based on write counter), loading reads the most recent block.
File A: blocks 2-3
File B: blocks 4-5
File C: blocks 6-7