Double Dragon MMC5 Patch

About this project

This is a Mapper Conversion hack for Double Dragon ROM from MMC1 to MMC5.

Features:

Expansion RAM ($5C00-$5FFF, read/write)
CPU $6000-$7FFF: 8 KB switchable PRG RAM bank
Bank switching included. Readme file for more info.
Extended RAM mode ($5104)

Read the Readme for changes in this version v1.0b

All emulators are now supported!

Database match: Double Dragon (USA) Database: No-Intro: Nintendo Entertainment System (v. 20180803-121122) File SHA-1: 84698B12F4E56A37C67BB47359758124C9B012BB File CRC32: 62AFE166 ROM SHA-1: 96356DA50FF4CD4E3D399181AC19DAFBF298EEA8 ROM CRC32: F1CC048

Readme & instructions

4818readme.txt

Double Dragon Mapper Conversion Patch FROM Mapper 1 (MMC1) TO Mapper 5 (MMC5) Converted by Dracula X RELEASE DATE: 11/27/19 Modified: 5/14/2021 MMC5 setup is located at $3FF10 CHR is located at $40010 PRG Bankswitch Routine is at $FEEE To switch banks from $C000 - $FFFF, use like so: LDA bank_number JSR $FFEE JMP to any location in $8000-$BFFF CHR Sprite Bankswitch Routine (Left side of PPU) is at $FE9E To switch sprite pages, use like so: LDA page_number JSR $FE9E CHR Background Bankswitch Routine (Right side of PPU) is at $FEC6 To switch background pages, use like so: LDA page_number JSR $FEC6 Nametable Mapping Routine (one of its uses is…

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Double Dragon
Mapper Conversion Patch
FROM Mapper 1 (MMC1) TO Mapper 5 (MMC5)
Converted by Dracula X
RELEASE DATE: 11/27/19
Modified: 5/14/2021


MMC5 setup is located at $3FF10
CHR is located at $40010

PRG Bankswitch Routine is at $FEEE

To switch banks from $C000 - $FFFF, use like so:

LDA bank_number
JSR $FFEE
JMP to any location in $8000-$BFFF




CHR Sprite Bankswitch Routine (Left side of PPU) is at $FE9E

To switch sprite pages, use like so:

LDA page_number
JSR $FE9E




CHR Background Bankswitch Routine (Right side of PPU) is at $FEC6

To switch background pages, use like so:

LDA page_number
JSR $FEC6




Nametable Mapping Routine (one of its uses is mirroring) is at $FE76

To change mirroring for instance, use like so:

LDA mirroring_number (#$50 for Horizontal, #$44 for Vertical)
JSR $FE76

This patch does not work for:
Double Dragon (Europe)

This patch also works for:
Sou Setsu Ryuu (Japan)

Hacks supported:
All!
Note: to get Double Dragon Remasted to work just add the changes
that I made to CHR Bank 1 and MMC5 setup and thats it.

Hacks not supported:
Double Dragon - MMC1 to MMC3

Use Delta Patcher to patch the xdelta file to the ROM. 
Ignore the checksum and then patch the file.

Changes for this version 1.0a
Fixed the PPU Viewer CHR Left and all hacks are now supported.

Changes for this version 1.0b
Fixed mmc5 setup and added Upper CHR Bank bits to CHR Bank 1
and all emulators are now supported.

Credits:
Rockman or RetroRain: for info on how to convert the mapper!
Disch: for his mapper docs and a better MMC5 startup!

All emulators are now supported!