diff options
Diffstat (limited to 'sd')
| -rw-r--r-- | sd/README.md | 68 |
1 files changed, 66 insertions, 2 deletions
diff --git a/sd/README.md b/sd/README.md index 32b9060..cf55cbc 100644 --- a/sd/README.md +++ b/sd/README.md @@ -39,7 +39,7 @@ A172,24,48 checksum, size in Mbit, number of banks (lorom needs twice as many banks as hirom for the same rom size) #### hirom64.map -This is a Nintendo Power mapping file that changes the mapping to a single 4MB HiRom game with 64Kbit/8KByte save. The first byte is used to specify the mapping. +This is a Nintendo Power SF Memory mapping file that changes the mapping to a single 4MB HiRom game with 64Kbit/8KByte save. The first byte is used to specify the mapping. Bit0-1 SRAM Size (0=2K, 1=8K, 2=32K, 3=None) ;ie. 2K SHL (N*2) Bit2-4 ROM Size (0=512K, 2=1.5M, 5=3M, 7=4M) ;ie. 512K*(N+1) @@ -55,7 +55,7 @@ Example: 01 -> 8K #### lorom256.map -This is a Nintendo Power mapping file that changes the mapping to a single 4MB LoRom game with 256Kbit/32 KByte save. +This is a Nintendo Power SF Memory mapping file that changes the mapping to a single 4MB LoRom game with 256Kbit/32 KByte save. Example: 0x1e = 0b 00 0 111 10 @@ -63,3 +63,67 @@ Example: 0 0b111 -> 7 -> 4M 0x10 -> 2 ->32k + +#### mbc5.map +This is a Nintendo Power GB Memory mapping file that changes the mapping to a single 1MB MBC5 game with 32 KByte save. + +GB Mapping Info (by skaman) +Entries start at 0x0 divided into 3 Byte segments + +For example, let's look at the start of the mapping for a multi-game cart: +A8 00 00 71 04 00 48 94 04 separates into +A8 00 00 MENU +71 04 00 GAME 1 +48 94 04 GAME 2 + +Byte 00 of each entry contains the MBC Type, ROM Size, and SRAM Size (start). +SRAM Size is 3 bits across Byte 00 and Byte 01. + MBC SZE SRAM +A8 = 101 010 00 0 MBC5, size 2 = 128KB +71 = 011 100 01 0 MBC3, size 4 = 512KB, SRAM 8KB +48 = 010 010 00 1 MBC2, size 2 = 128KB, SRAM MBC2 + +Byte 00: 1st 3 Bits = MBC Type + 000 = MBC0 + 001 = MBC1 + 010 = MBC2 + 011 = MBC3 + 101 = MBC5 + +Byte 00: 2nd 3 Bits = ROM Size (minimum size is 128KB due to block size) + 010 = Size 2 - 128KB + 011 = Size 3 - 256KB + 100 = Size 4 - 512KB + 101 = Size 5 - 1MB + +Byte 00: Last 2 Bits (bit1..bit0) + Byte 01: 1st Bit (bit7) = SRAM Size + 00 0 = NONE + 00 1 = SRAM MBC2 + 01 0 = SRAM 8KB + 01 1 = SRAM 32KB + +Byte 01 contains the SRAM Size (end) and ROM Block in the Flash. +ROM Blocks are 128KB (8 total) +Byte 01: Last 7 Bits (bit6..bit0) = ROM Block + 00 = ROM Block 0 start offset 0KB + 04 = ROM Block 1 start offset 128KB + 08 = ROM Block 2 start offset 256KB + 0C = ROM Block 3 start offset 384KB + 10 = ROM Block 4 start offset 512KB + 14 = ROM Block 5 start offset 640KB + 18 = ROM Block 6 start offset 768KB + 1C = ROM Block 7 start offset 896KB + +Byte 02 contains the RAM Block in the SRAM. +RAM Blocks are 8KB (16 total) +Byte 02: RAM Block: + 00 = RAM Block 0 start offset 0KB + 04 = RAM Block 1 start offset 8KB + 08 = RAM Block 2 start offset 16KB + 0C = RAM Block 3 start offset 24KB + and so on until RAM Block 15. + +Going back to our example cart: +A8 00 00 MENU: MBC5, size 2 = 128KB, ROM Block 0, RAM Block 0 (Ignored since SRAM is 000) +71 04 00 GAME 1: MBC3, size 4 = 512KB, SRAM 8KB, ROM Block 1, RAM Block 0 +48 94 04 GAME 2: MBC2, size 2 = 128KB, SRAM MBC2, ROM Block 5, RAM Block 1 |