LaTumbaMuerto.com

NES Release Guide

Converting MIDI files into a playable music NES (Nintendo Entertainment System) cartridge involves several steps, including preparing your MIDI files, converting them into a format compatible with the NES’s sound hardware, assembling an NES ROM, and finally flashing the ROM onto a physical cartridge. Below is a detailed, step-by-step guide to help you through the process.

Prerequisites

Before you begin, ensure you have the following:

A MIDI file that you wish to convert.
A computer capable of running the necessary software (Windows, macOS, or Linux).
Basic knowledge of command-line operations and programming concepts.
NES Development Tools: Such as NESASM or cc65 for assembling code.
NES Sound Tools: FamiTracker or FamiStudio for audio creation.
Hardware: A programmable NES cartridge (e.g., INL Retro, Kazzo) and an NES console for testing.

Step 1: Prepare Your MIDI File

1. Simplify the MIDI File

The NES has specific audio limitations:

Five Audio Channels:
- Two Pulse Waves: For melody and harmony.
- One Triangle Wave: Often used for bass.
- Noise Channel: For percussion.
- DPCM Channel: For sampled sounds (limited and advanced usage).

Use a MIDI editor to reduce your MIDI file to these channels, ensuring each part is monophonic where necessary.

Recommended MIDI Editors:

Anvil Studio (Windows)
MuseScore (Windows, macOS, Linux)
LMMS (Windows, macOS, Linux)

Step 2: Install FamiTracker or FamiStudio

1. Download FamiTracker

Visit the FamiTracker Website for the official version.
Alternatively, download the FamiTracker Community Edition.

2. Download FamiStudio (Alternative)

Visit the FamiStudio GitHub Repository.
FamiStudio provides a more user-friendly interface and modern features.

3. Install the Software

Install FamiTracker or FamiStudio following the provided instructions.
Ensure the software runs correctly on your system.

Step 3: Import and Edit MIDI in FamiTracker/FamiStudio

1. Import MIDI File

In FamiTracker:
- Go to File > Import MIDI.
- Select your simplified MIDI file.
In FamiStudio:
- Go to Project > Import and select Import MIDI File.

2. Map MIDI Channels to NES Channels

Assign each MIDI track to the appropriate NES audio channel.
Adjust instruments to use NES-compatible sounds.

3. Edit the Song

Fine-tune notes, volumes, and effects to match the NES’s capabilities.
Use built-in instruments or create custom ones that emulate NES sounds.

4. Test the Music

Press the Play button to listen to your track within the software.
Make necessary adjustments to improve sound quality and compatibility.

Step 4: Export the Music to NSF Format

1. Export from FamiTracker

Go to File > Export.
Choose NES Sound Format (*.nsf) as the export format.
Save the file as your_song.nsf.

2. Export from FamiStudio

Go to Project > Export and select Export NSF.
Save the file accordingly.

Note: The NSF file is a music format specifically for the NES.

Step 5: Set Up NES Development Environment

1. Install NESASM or cc65

NESASM:
- Download from NESASM GitHub Repository.
cc65:
- Visit the cc65 Website.
- Download and install the assembler suite.

2. Create Project Directories

Create a new directory for your NES project.
Inside, create subdirectories like src for source code and music for the NSF file.

Step 6: Integrate NSF into NES ROM

1. Convert NSF to Assembly Data (Optional)

If you need to include the NSF data directly into your assembly code, you can convert it to an object file.
Alternatively, you can load the NSF file as is, depending on your method.

2. Create the Main Assembly Code

Create a file named main.asm in your src directory with the following content:

    .include "nes.inc"

    .org $C000

Start:
    SEI             ; Disable interrupts
    CLD             ; Clear decimal mode
    LDX #$40
    STX $4017       ; Disable APU frame IRQ
    LDX #$FF
    TXS             ; Set up stack
    INX
    STX $2000       ; Disable NMI
    STX $2001       ; Disable rendering
    STX $4010       ; Disable DMC IRQs

    JSR PlayMusic   ; Jump to music playback routine

Forever:
    JMP Forever     ; Infinite loop

; Music playback routine
PlayMusic:
    ; Initialize NSF player here
    ; Load NSF data into memory
    ; Set up pointers
    RTS

    .bank 1
    .org $E000

    ; Include NSF data
    .incbin "../music/your_song.nsf"

    .bank 2
    .org $FFFA
    .dw NMI          ; NMI vector
    .dw Reset        ; Reset vector
    .dw IRQ          ; IRQ/BRK vector

NMI:
    RTI

Reset:
    JMP Start

IRQ:
    RTI

This is a simplified example. The actual implementation requires a proper NSF player routine.
There are existing NSF player source codes available that you can include in your project.

3. Use an Existing NSF Player

Nerdy Nights NSF Player: A basic NSF player example.
Kevin Horton’s NSF Player: More advanced and supports more features.

Step 7: Compile the NES ROM

1. Using NESASM

Open a command prompt or terminal in your project directory.
Run:

nesasm src/main.asm

This will assemble your code into an NES ROM.

2. Using cc65

Compile and link your code using cc65 tools:

ca65 src/main.asm -o main.o
ld65 main.o -C nes.cfg -o game.nes

Ensure you have a correct configuration file (nes.cfg) for the NES.

3. Troubleshooting

If errors occur, check your assembly code for syntax issues.
Ensure all included files and paths are correct.

Step 8: Test the ROM in an Emulator

1. Choose an Emulator

FCEUX (Windows, macOS, Linux): Download FCEUX
Nestopia (Windows, macOS, Linux): Download Nestopia
Mesen (Windows, Linux): Download Mesen

2. Load and Test the ROM

Open the emulator and load your assembled ROM file (e.g., game.nes).
Verify that the music plays correctly.
Use the emulator’s debugging tools if needed.

Step 9: Flash the ROM onto an NES Cartridge

1. Obtain a Flashable Cartridge

INL Retro Programmers and Boards: Infinite NES Lives
Kazzo Cartridge Dumper/Programmer: Allows flashing to donor cartridges.

2. Install Necessary Drivers and Software

Install drivers for the programmer hardware.
Install software provided by the manufacturer to flash the ROM.

3. Prepare the Cartridge

Use a compatible donor cartridge or flash cartridge.
Ensure the cartridge hardware supports the mapper used in your ROM (most basic music ROMs use NROM).

4. Flash the ROM

Connect the cartridge programmer to your computer.
Use the provided software to write your game.nes ROM to the cartridge.

Step 10: Play the Cartridge on an NES Console

1. Insert the Cartridge

Place the flashed cartridge into your NES console.

2. Test the Music

Turn on the NES.
Confirm that the music plays as intended on the actual hardware.

Additional Tips

Understanding Mappers: NES cartridges use mappers to handle memory beyond the base capabilities. For simple applications, use the NROM mapper (mapper 0).
NSF Players: Integrating an NSF player into your ROM can be complex. Consider using existing open-source NSF player code to simplify the process.
Optimize Audio Quality: The NES has limitations in audio playback. Fine-tune your module files for better performance.
Alternative Tools: If you encounter issues with FamiTracker, consider using FamiStudio, which might offer a more intuitive interface.
Community Support: Engage with communities like NESDev Forums for assistance.
Legal Considerations: Ensure that you have the rights to distribute any music you convert, especially if the MIDI files are of commercial songs.

Summary

By following these steps, you can successfully convert MIDI files into a playable music NES cartridge. This process involves:

Preparing and simplifying your MIDI file.
Converting the MIDI to an NES-compatible format using FamiTracker or FamiStudio.
Assembling the music into an NES ROM using an assembler like NESASM or cc65.
Testing the ROM in an emulator.
Flashing the ROM onto a physical cartridge using appropriate hardware.
Playing the cartridge on an actual NES console.

This not only allows you to enjoy custom music on original hardware but also provides a hands-on experience with retro console development.

Disclaimer: Working with NES hardware and software development involves a learning curve and attention to detail. Always back up your work and proceed with caution when flashing hardware. Additionally, respect intellectual property laws when using or distributing music.