The D51 disassembler is a specialized tool modified to support the unique A5 instruction set found on Oki 8XC154 microcontrollers.

Important

This tool is intended for advanced users performing reverse engineering or custom ROM development on supported Honda ECU hardware.

Usage and Compatibility#

The tool is available in both Linux and Windows binary formats. To operate the disassembler, execute the binary via the command line interface.

• Linux Binaries: Compiled for standard Linux distributions.
• Windows Binaries: Compiled for Windows environments.

Command Line Interface#

To view available flags, input parameters, and configuration options, execute the binary with the help argument:

./d51 --help

Technical Specifications#

The primary modification to the standard D51 codebase is the implementation of the A5 instruction opcode, which is non-standard for generic 8051-based disassemblers but required for proper decoding of Oki 8XC154 firmware.

Tip

Always verify the checksum of your ROM file before and after disassembly to ensure data integrity during the conversion process.