This document provides a centralized reference for the Oki 66K processor family, which serves as the foundation for most Honda OBD1 and OBD2 engine control units.

Documentation#

• 66k Assembler Docs0: Official factory documentation regarding the Oki 66xxx processor architecture.
• 66k Operations: A comprehensive list of standard 66xxx assembler operations and their specific implementation within PGM-FI systems.

Utilities#

Assemblers and Disassemblers#

• ASM6620: Open-source assembler/disassembler for the Oki Nx8/200 66k processor series.
• 66507 DASM: Specialized disassembler for the OBD2 Oki 66507 processor.

Development Environment Support#

• jEdit Mode Definition: assembly-Oki66k.xml provides syntax highlighting and structure for the jEdit text editor.
• okiedit: A Win32-based syntax-highlighting editor specifically designed for 66k assembly development.
• TextPad Syntax: Custom syntax definition files for TextPad 4.6 to support 66k assembly formatting.

Note

Ensure that your development environment is configured for the specific processor variant (e.g., 66507 vs. 66200) to avoid instruction set mismatches during disassembly or assembly.